mirror of https://github.com/django/django.git
2657 lines
78 KiB
Plaintext
2657 lines
78 KiB
Plaintext
==================================
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Built-in template tags and filters
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==================================
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This document describes Django's built-in template tags and filters. It is
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recommended that you use the :doc:`automatic documentation
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</ref/contrib/admin/admindocs>`, if available, as this will also include
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documentation for any custom tags or filters installed.
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.. _ref-templates-builtins-tags:
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Built-in tag reference
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======================
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.. highlight:: html+django
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.. templatetag:: autoescape
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``autoescape``
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--------------
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Controls the current auto-escaping behavior. This tag takes either ``on`` or
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``off`` as an argument and that determines whether auto-escaping is in effect
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inside the block. The block is closed with an ``endautoescape`` ending tag.
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When auto-escaping is in effect, all variable content has HTML escaping applied
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to it before placing the result into the output (but after any filters have
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been applied). This is equivalent to manually applying the :tfilter:`escape`
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filter to each variable.
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The only exceptions are variables that are already marked as "safe" from
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escaping, either by the code that populated the variable, or because it has had
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the :tfilter:`safe` or :tfilter:`escape` filters applied.
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Sample usage::
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{% autoescape on %}
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{{ body }}
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{% endautoescape %}
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.. templatetag:: block
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``block``
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---------
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Defines a block that can be overridden by child templates. See
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:ref:`Template inheritance <template-inheritance>` for more information.
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.. templatetag:: comment
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``comment``
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-----------
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Ignores everything between ``{% comment %}`` and ``{% endcomment %}``.
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An optional note may be inserted in the first tag. For example, this is
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useful when commenting out code for documenting why the code was disabled.
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Sample usage::
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<p>Rendered text with {{ pub_date|date:"c" }}</p>
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{% comment "Optional note" %}
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<p>Commented out text with {{ create_date|date:"c" }}</p>
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{% endcomment %}
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``comment`` tags cannot be nested.
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.. templatetag:: csrf_token
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``csrf_token``
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--------------
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This tag is used for CSRF protection, as described in the documentation for
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:doc:`Cross Site Request Forgeries </ref/csrf>`.
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.. templatetag:: cycle
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``cycle``
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---------
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Produces one of its arguments each time this tag is encountered. The first
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argument is produced on the first encounter, the second argument on the second
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encounter, and so forth. Once all arguments are exhausted, the tag cycles to
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the first argument and produces it again.
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This tag is particularly useful in a loop::
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{% for o in some_list %}
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<tr class="{% cycle 'row1' 'row2' %}">
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...
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</tr>
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{% endfor %}
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The first iteration produces HTML that refers to class ``row1``, the second to
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``row2``, the third to ``row1`` again, and so on for each iteration of the
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loop.
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You can use variables, too. For example, if you have two template variables,
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``rowvalue1`` and ``rowvalue2``, you can alternate between their values like
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this::
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{% for o in some_list %}
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<tr class="{% cycle rowvalue1 rowvalue2 %}">
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...
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</tr>
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{% endfor %}
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Variables included in the cycle will be escaped. You can disable auto-escaping
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with::
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{% for o in some_list %}
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<tr class="{% autoescape off %}{% cycle rowvalue1 rowvalue2 %}{% endautoescape %}">
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...
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</tr>
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{% endfor %}
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You can mix variables and strings::
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{% for o in some_list %}
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<tr class="{% cycle 'row1' rowvalue2 'row3' %}">
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...
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</tr>
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{% endfor %}
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In some cases you might want to refer to the current value of a cycle
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without advancing to the next value. To do this,
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give the ``{% cycle %}`` tag a name, using "as", like this::
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{% cycle 'row1' 'row2' as rowcolors %}
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From then on, you can insert the current value of the cycle wherever you'd like
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in your template by referencing the cycle name as a context variable. If you
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want to move the cycle to the next value independently of the original
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``cycle`` tag, you can use another ``cycle`` tag and specify the name of the
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variable. So, the following template::
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<tr>
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<td class="{% cycle 'row1' 'row2' as rowcolors %}">...</td>
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<td class="{{ rowcolors }}">...</td>
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</tr>
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<tr>
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<td class="{% cycle rowcolors %}">...</td>
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<td class="{{ rowcolors }}">...</td>
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</tr>
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would output::
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<tr>
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<td class="row1">...</td>
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<td class="row1">...</td>
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</tr>
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<tr>
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<td class="row2">...</td>
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<td class="row2">...</td>
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</tr>
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You can use any number of values in a ``cycle`` tag, separated by spaces.
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Values enclosed in single quotes (``'``) or double quotes (``"``) are treated
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as string literals, while values without quotes are treated as template
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variables.
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By default, when you use the ``as`` keyword with the cycle tag, the
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usage of ``{% cycle %}`` that initiates the cycle will itself produce
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the first value in the cycle. This could be a problem if you want to
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use the value in a nested loop or an included template. If you only want
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to declare the cycle but not produce the first value, you can add a
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``silent`` keyword as the last keyword in the tag. For example::
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{% for obj in some_list %}
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{% cycle 'row1' 'row2' as rowcolors silent %}
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<tr class="{{ rowcolors }}">{% include "subtemplate.html" %}</tr>
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{% endfor %}
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This will output a list of ``<tr>`` elements with ``class``
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alternating between ``row1`` and ``row2``. The subtemplate will have
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access to ``rowcolors`` in its context and the value will match the class
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of the ``<tr>`` that encloses it. If the ``silent`` keyword were to be
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omitted, ``row1`` and ``row2`` would be emitted as normal text, outside the
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``<tr>`` element.
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When the silent keyword is used on a cycle definition, the silence
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automatically applies to all subsequent uses of that specific cycle tag.
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The following template would output *nothing*, even though the second
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call to ``{% cycle %}`` doesn't specify ``silent``::
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{% cycle 'row1' 'row2' as rowcolors silent %}
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{% cycle rowcolors %}
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You can use the :ttag:`resetcycle` tag to make a ``{% cycle %}`` tag restart
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from its first value when it's next encountered.
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.. templatetag:: debug
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``debug``
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---------
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Outputs a whole load of debugging information, including the current context
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and imported modules.
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.. templatetag:: extends
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``extends``
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-----------
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Signals that this template extends a parent template.
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This tag can be used in two ways:
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* ``{% extends "base.html" %}`` (with quotes) uses the literal value
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``"base.html"`` as the name of the parent template to extend.
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* ``{% extends variable %}`` uses the value of ``variable``. If the variable
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evaluates to a string, Django will use that string as the name of the
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parent template. If the variable evaluates to a ``Template`` object,
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Django will use that object as the parent template.
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See :ref:`template-inheritance` for more information.
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Normally the template name is relative to the template loader's root directory.
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A string argument may also be a relative path starting with ``./`` or ``../``.
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For example, assume the following directory structure::
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dir1/
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template.html
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base2.html
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my/
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base3.html
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base1.html
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In ``template.html``, the following paths would be valid::
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{% extends "./base2.html" %}
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{% extends "../base1.html" %}
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{% extends "./my/base3.html" %}
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.. templatetag:: filter
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``filter``
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----------
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Filters the contents of the block through one or more filters. Multiple
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filters can be specified with pipes and filters can have arguments, just as
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in variable syntax.
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Note that the block includes *all* the text between the ``filter`` and
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``endfilter`` tags.
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Sample usage::
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{% filter force_escape|lower %}
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This text will be HTML-escaped, and will appear in all lowercase.
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{% endfilter %}
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.. note::
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The :tfilter:`escape` and :tfilter:`safe` filters are not acceptable
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arguments. Instead, use the :ttag:`autoescape` tag to manage autoescaping
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for blocks of template code.
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.. templatetag:: firstof
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``firstof``
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-----------
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Outputs the first argument variable that is not "false" (i.e. exists, is not
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empty, is not a false boolean value, and is not a zero numeric value). Outputs
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nothing if all the passed variables are "false".
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Sample usage::
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{% firstof var1 var2 var3 %}
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This is equivalent to::
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{% if var1 %}
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{{ var1 }}
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{% elif var2 %}
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{{ var2 }}
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{% elif var3 %}
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{{ var3 }}
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{% endif %}
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You can also use a literal string as a fallback value in case all
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passed variables are False::
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{% firstof var1 var2 var3 "fallback value" %}
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This tag auto-escapes variable values. You can disable auto-escaping with::
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{% autoescape off %}
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{% firstof var1 var2 var3 "<strong>fallback value</strong>" %}
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{% endautoescape %}
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Or if only some variables should be escaped, you can use::
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{% firstof var1 var2|safe var3 "<strong>fallback value</strong>"|safe %}
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You can use the syntax ``{% firstof var1 var2 var3 as value %}`` to store the
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output inside a variable.
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.. templatetag:: for
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``for``
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-------
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Loops over each item in an array, making the item available in a context
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variable. For example, to display a list of athletes provided in
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``athlete_list``::
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<ul>
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{% for athlete in athlete_list %}
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<li>{{ athlete.name }}</li>
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{% endfor %}
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</ul>
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You can loop over a list in reverse by using
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``{% for obj in list reversed %}``.
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If you need to loop over a list of lists, you can unpack the values
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in each sublist into individual variables. For example, if your context
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contains a list of (x,y) coordinates called ``points``, you could use the
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following to output the list of points::
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{% for x, y in points %}
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There is a point at {{ x }},{{ y }}
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{% endfor %}
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This can also be useful if you need to access the items in a dictionary.
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For example, if your context contained a dictionary ``data``, the following
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would display the keys and values of the dictionary::
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{% for key, value in data.items %}
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{{ key }}: {{ value }}
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{% endfor %}
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Keep in mind that for the dot operator, dictionary key lookup takes precedence
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over method lookup. Therefore if the ``data`` dictionary contains a key named
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``'items'``, ``data.items`` will return ``data['items']`` instead of
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``data.items()``. Avoid adding keys that are named like dictionary methods if
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you want to use those methods in a template (``items``, ``values``, ``keys``,
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etc.). Read more about the lookup order of the dot operator in the
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:ref:`documentation of template variables <template-variables>`.
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The for loop sets a number of variables available within the loop:
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========================== ===============================================
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Variable Description
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========================== ===============================================
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``forloop.counter`` The current iteration of the loop (1-indexed)
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``forloop.counter0`` The current iteration of the loop (0-indexed)
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``forloop.revcounter`` The number of iterations from the end of the
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loop (1-indexed)
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``forloop.revcounter0`` The number of iterations from the end of the
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loop (0-indexed)
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``forloop.first`` True if this is the first time through the loop
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``forloop.last`` True if this is the last time through the loop
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``forloop.parentloop`` For nested loops, this is the loop surrounding
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the current one
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========================== ===============================================
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``for`` ... ``empty``
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---------------------
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The ``for`` tag can take an optional ``{% empty %}`` clause whose text is
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displayed if the given array is empty or could not be found::
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<ul>
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{% for athlete in athlete_list %}
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<li>{{ athlete.name }}</li>
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{% empty %}
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<li>Sorry, no athletes in this list.</li>
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{% endfor %}
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</ul>
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The above is equivalent to -- but shorter, cleaner, and possibly faster
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than -- the following::
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<ul>
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{% if athlete_list %}
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{% for athlete in athlete_list %}
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<li>{{ athlete.name }}</li>
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{% endfor %}
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{% else %}
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<li>Sorry, no athletes in this list.</li>
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{% endif %}
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</ul>
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.. templatetag:: if
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``if``
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------
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The ``{% if %}`` tag evaluates a variable, and if that variable is "true" (i.e.
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exists, is not empty, and is not a false boolean value) the contents of the
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block are output::
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{% if athlete_list %}
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Number of athletes: {{ athlete_list|length }}
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{% elif athlete_in_locker_room_list %}
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Athletes should be out of the locker room soon!
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{% else %}
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No athletes.
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{% endif %}
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In the above, if ``athlete_list`` is not empty, the number of athletes will be
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displayed by the ``{{ athlete_list|length }}`` variable.
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As you can see, the ``if`` tag may take one or several ``{% elif %}``
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clauses, as well as an ``{% else %}`` clause that will be displayed if all
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previous conditions fail. These clauses are optional.
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Boolean operators
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~~~~~~~~~~~~~~~~~
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:ttag:`if` tags may use ``and``, ``or`` or ``not`` to test a number of
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variables or to negate a given variable::
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{% if athlete_list and coach_list %}
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Both athletes and coaches are available.
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{% endif %}
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{% if not athlete_list %}
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There are no athletes.
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{% endif %}
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{% if athlete_list or coach_list %}
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There are some athletes or some coaches.
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{% endif %}
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{% if not athlete_list or coach_list %}
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There are no athletes or there are some coaches.
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{% endif %}
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{% if athlete_list and not coach_list %}
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There are some athletes and absolutely no coaches.
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{% endif %}
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Use of both ``and`` and ``or`` clauses within the same tag is allowed, with
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``and`` having higher precedence than ``or`` e.g.::
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{% if athlete_list and coach_list or cheerleader_list %}
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will be interpreted like:
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.. code-block:: python
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if (athlete_list and coach_list) or cheerleader_list
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Use of actual parentheses in the :ttag:`if` tag is invalid syntax. If you need
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them to indicate precedence, you should use nested :ttag:`if` tags.
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:ttag:`if` tags may also use the operators ``==``, ``!=``, ``<``, ``>``,
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``<=``, ``>=``, ``in``, ``not in``, ``is``, and ``is not`` which work as
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follows:
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``==`` operator
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^^^^^^^^^^^^^^^
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Equality. Example::
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{% if somevar == "x" %}
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This appears if variable somevar equals the string "x"
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{% endif %}
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``!=`` operator
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^^^^^^^^^^^^^^^
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Inequality. Example::
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{% if somevar != "x" %}
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This appears if variable somevar does not equal the string "x",
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or if somevar is not found in the context
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{% endif %}
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``<`` operator
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^^^^^^^^^^^^^^
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Less than. Example::
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{% if somevar < 100 %}
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This appears if variable somevar is less than 100.
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{% endif %}
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``>`` operator
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^^^^^^^^^^^^^^
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Greater than. Example::
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{% if somevar > 0 %}
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This appears if variable somevar is greater than 0.
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{% endif %}
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``<=`` operator
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^^^^^^^^^^^^^^^
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Less than or equal to. Example::
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{% if somevar <= 100 %}
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This appears if variable somevar is less than 100 or equal to 100.
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{% endif %}
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``>=`` operator
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^^^^^^^^^^^^^^^
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Greater than or equal to. Example::
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{% if somevar >= 1 %}
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This appears if variable somevar is greater than 1 or equal to 1.
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{% endif %}
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``in`` operator
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^^^^^^^^^^^^^^^
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Contained within. This operator is supported by many Python containers to test
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whether the given value is in the container. The following are some examples
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of how ``x in y`` will be interpreted::
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{% if "bc" in "abcdef" %}
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This appears since "bc" is a substring of "abcdef"
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{% endif %}
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{% if "hello" in greetings %}
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If greetings is a list or set, one element of which is the string
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"hello", this will appear.
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{% endif %}
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{% if user in users %}
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If users is a QuerySet, this will appear if user is an
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instance that belongs to the QuerySet.
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{% endif %}
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``not in`` operator
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^^^^^^^^^^^^^^^^^^^
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Not contained within. This is the negation of the ``in`` operator.
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``is`` operator
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^^^^^^^^^^^^^^^
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Object identity. Tests if two values are the same object. Example::
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{% if somevar is True %}
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This appears if and only if somevar is True.
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{% endif %}
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{% if somevar is None %}
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This appears if somevar is None, or if somevar is not found in the context.
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{% endif %}
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``is not`` operator
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^^^^^^^^^^^^^^^^^^^
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Negated object identity. Tests if two values are not the same object. This is
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the negation of the ``is`` operator. Example::
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{% if somevar is not True %}
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This appears if somevar is not True, or if somevar is not found in the
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context.
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{% endif %}
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{% if somevar is not None %}
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This appears if and only if somevar is not None.
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{% endif %}
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Filters
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~~~~~~~
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|
|
You can also use filters in the :ttag:`if` expression. For example::
|
|
|
|
{% if messages|length >= 100 %}
|
|
You have lots of messages today!
|
|
{% endif %}
|
|
|
|
Complex expressions
|
|
~~~~~~~~~~~~~~~~~~~
|
|
|
|
All of the above can be combined to form complex expressions. For such
|
|
expressions, it can be important to know how the operators are grouped when the
|
|
expression is evaluated - that is, the precedence rules. The precedence of the
|
|
operators, from lowest to highest, is as follows:
|
|
|
|
* ``or``
|
|
* ``and``
|
|
* ``not``
|
|
* ``in``
|
|
* ``==``, ``!=``, ``<``, ``>``, ``<=``, ``>=``
|
|
|
|
(This follows Python exactly). So, for example, the following complex
|
|
:ttag:`if` tag::
|
|
|
|
{% if a == b or c == d and e %}
|
|
|
|
...will be interpreted as:
|
|
|
|
.. code-block:: python
|
|
|
|
(a == b) or ((c == d) and e)
|
|
|
|
If you need different precedence, you will need to use nested :ttag:`if` tags.
|
|
Sometimes that is better for clarity anyway, for the sake of those who do not
|
|
know the precedence rules.
|
|
|
|
The comparison operators cannot be 'chained' like in Python or in mathematical
|
|
notation. For example, instead of using::
|
|
|
|
{% if a > b > c %} (WRONG)
|
|
|
|
you should use::
|
|
|
|
{% if a > b and b > c %}
|
|
|
|
.. templatetag:: ifchanged
|
|
|
|
``ifchanged``
|
|
-------------
|
|
|
|
Check if a value has changed from the last iteration of a loop.
|
|
|
|
The ``{% ifchanged %}`` block tag is used within a loop. It has two possible
|
|
uses.
|
|
|
|
1. Checks its own rendered contents against its previous state and only
|
|
displays the content if it has changed. For example, this displays a list of
|
|
days, only displaying the month if it changes::
|
|
|
|
<h1>Archive for {{ year }}</h1>
|
|
|
|
{% for date in days %}
|
|
{% ifchanged %}<h3>{{ date|date:"F" }}</h3>{% endifchanged %}
|
|
<a href="{{ date|date:"M/d"|lower }}/">{{ date|date:"j" }}</a>
|
|
{% endfor %}
|
|
|
|
2. If given one or more variables, check whether any variable has changed.
|
|
For example, the following shows the date every time it changes, while
|
|
showing the hour if either the hour or the date has changed::
|
|
|
|
{% for date in days %}
|
|
{% ifchanged date.date %} {{ date.date }} {% endifchanged %}
|
|
{% ifchanged date.hour date.date %}
|
|
{{ date.hour }}
|
|
{% endifchanged %}
|
|
{% endfor %}
|
|
|
|
The ``ifchanged`` tag can also take an optional ``{% else %}`` clause that
|
|
will be displayed if the value has not changed::
|
|
|
|
{% for match in matches %}
|
|
<div style="background-color:
|
|
{% ifchanged match.ballot_id %}
|
|
{% cycle "red" "blue" %}
|
|
{% else %}
|
|
gray
|
|
{% endifchanged %}
|
|
">{{ match }}</div>
|
|
{% endfor %}
|
|
|
|
.. templatetag:: include
|
|
|
|
``include``
|
|
-----------
|
|
|
|
Loads a template and renders it with the current context. This is a way of
|
|
"including" other templates within a template.
|
|
|
|
The template name can either be a variable or a hard-coded (quoted) string,
|
|
in either single or double quotes.
|
|
|
|
This example includes the contents of the template ``"foo/bar.html"``::
|
|
|
|
{% include "foo/bar.html" %}
|
|
|
|
Normally the template name is relative to the template loader's root directory.
|
|
A string argument may also be a relative path starting with ``./`` or ``../``
|
|
as described in the :ttag:`extends` tag.
|
|
|
|
This example includes the contents of the template whose name is contained in
|
|
the variable ``template_name``::
|
|
|
|
{% include template_name %}
|
|
|
|
The variable may also be any object with a ``render()`` method that accepts a
|
|
context. This allows you to reference a compiled ``Template`` in your context.
|
|
|
|
Additionally, the variable may be an iterable of template names, in which case
|
|
the first that can be loaded will be used, as per
|
|
:func:`~django.template.loader.select_template`.
|
|
|
|
An included template is rendered within the context of the template that
|
|
includes it. This example produces the output ``"Hello, John!"``:
|
|
|
|
* Context: variable ``person`` is set to ``"John"`` and variable ``greeting``
|
|
is set to ``"Hello"``.
|
|
|
|
* Template::
|
|
|
|
{% include "name_snippet.html" %}
|
|
|
|
* The ``name_snippet.html`` template::
|
|
|
|
{{ greeting }}, {{ person|default:"friend" }}!
|
|
|
|
You can pass additional context to the template using keyword arguments::
|
|
|
|
{% include "name_snippet.html" with person="Jane" greeting="Hello" %}
|
|
|
|
If you want to render the context only with the variables provided (or even
|
|
no variables at all), use the ``only`` option. No other variables are
|
|
available to the included template::
|
|
|
|
{% include "name_snippet.html" with greeting="Hi" only %}
|
|
|
|
.. note::
|
|
The :ttag:`include` tag should be considered as an implementation of
|
|
"render this subtemplate and include the HTML", not as "parse this
|
|
subtemplate and include its contents as if it were part of the parent".
|
|
This means that there is no shared state between included templates --
|
|
each include is a completely independent rendering process.
|
|
|
|
Blocks are evaluated *before* they are included. This means that a template
|
|
that includes blocks from another will contain blocks that have *already
|
|
been evaluated and rendered* - not blocks that can be overridden by, for
|
|
example, an extending template.
|
|
|
|
.. templatetag:: load
|
|
|
|
``load``
|
|
--------
|
|
|
|
Loads a custom template tag set.
|
|
|
|
For example, the following template would load all the tags and filters
|
|
registered in ``somelibrary`` and ``otherlibrary`` located in package
|
|
``package``::
|
|
|
|
{% load somelibrary package.otherlibrary %}
|
|
|
|
You can also selectively load individual filters or tags from a library, using
|
|
the ``from`` argument. In this example, the template tags/filters named ``foo``
|
|
and ``bar`` will be loaded from ``somelibrary``::
|
|
|
|
{% load foo bar from somelibrary %}
|
|
|
|
See :doc:`Custom tag and filter libraries </howto/custom-template-tags>` for
|
|
more information.
|
|
|
|
.. templatetag:: lorem
|
|
|
|
``lorem``
|
|
---------
|
|
|
|
Displays random "lorem ipsum" Latin text. This is useful for providing sample
|
|
data in templates.
|
|
|
|
Usage::
|
|
|
|
{% lorem [count] [method] [random] %}
|
|
|
|
The ``{% lorem %}`` tag can be used with zero, one, two or three arguments.
|
|
The arguments are:
|
|
|
|
=========== =============================================================
|
|
Argument Description
|
|
=========== =============================================================
|
|
``count`` A number (or variable) containing the number of paragraphs or
|
|
words to generate (default is 1).
|
|
``method`` Either ``w`` for words, ``p`` for HTML paragraphs or ``b``
|
|
for plain-text paragraph blocks (default is ``b``).
|
|
``random`` The word ``random``, which if given, does not use the common
|
|
paragraph ("Lorem ipsum dolor sit amet...") when generating
|
|
text.
|
|
=========== =============================================================
|
|
|
|
Examples:
|
|
|
|
* ``{% lorem %}`` will output the common "lorem ipsum" paragraph.
|
|
* ``{% lorem 3 p %}`` will output the common "lorem ipsum" paragraph
|
|
and two random paragraphs each wrapped in HTML ``<p>`` tags.
|
|
* ``{% lorem 2 w random %}`` will output two random Latin words.
|
|
|
|
.. templatetag:: now
|
|
|
|
``now``
|
|
-------
|
|
|
|
Displays the current date and/or time, using a format according to the given
|
|
string. Such string can contain format specifiers characters as described
|
|
in the :tfilter:`date` filter section.
|
|
|
|
Example::
|
|
|
|
It is {% now "jS F Y H:i" %}
|
|
|
|
Note that you can backslash-escape a format string if you want to use the
|
|
"raw" value. In this example, both "o" and "f" are backslash-escaped, because
|
|
otherwise each is a format string that displays the year and the time,
|
|
respectively::
|
|
|
|
It is the {% now "jS \o\f F" %}
|
|
|
|
This would display as "It is the 4th of September".
|
|
|
|
.. note::
|
|
|
|
The format passed can also be one of the predefined ones
|
|
:setting:`DATE_FORMAT`, :setting:`DATETIME_FORMAT`,
|
|
:setting:`SHORT_DATE_FORMAT` or :setting:`SHORT_DATETIME_FORMAT`.
|
|
The predefined formats may vary depending on the current locale and
|
|
if :doc:`/topics/i18n/formatting` is enabled, e.g.::
|
|
|
|
It is {% now "SHORT_DATETIME_FORMAT" %}
|
|
|
|
You can also use the syntax ``{% now "Y" as current_year %}`` to store the
|
|
output (as a string) inside a variable. This is useful if you want to use
|
|
``{% now %}`` inside a template tag like :ttag:`blocktranslate` for example::
|
|
|
|
{% now "Y" as current_year %}
|
|
{% blocktranslate %}Copyright {{ current_year }}{% endblocktranslate %}
|
|
|
|
.. templatetag:: regroup
|
|
|
|
``regroup``
|
|
-----------
|
|
|
|
Regroups a list of alike objects by a common attribute.
|
|
|
|
This complex tag is best illustrated by way of an example: say that ``cities``
|
|
is a list of cities represented by dictionaries containing ``"name"``,
|
|
``"population"``, and ``"country"`` keys:
|
|
|
|
.. code-block:: python
|
|
|
|
cities = [
|
|
{'name': 'Mumbai', 'population': '19,000,000', 'country': 'India'},
|
|
{'name': 'Calcutta', 'population': '15,000,000', 'country': 'India'},
|
|
{'name': 'New York', 'population': '20,000,000', 'country': 'USA'},
|
|
{'name': 'Chicago', 'population': '7,000,000', 'country': 'USA'},
|
|
{'name': 'Tokyo', 'population': '33,000,000', 'country': 'Japan'},
|
|
]
|
|
|
|
...and you'd like to display a hierarchical list that is ordered by country,
|
|
like this:
|
|
|
|
* India
|
|
|
|
* Mumbai: 19,000,000
|
|
* Calcutta: 15,000,000
|
|
|
|
* USA
|
|
|
|
* New York: 20,000,000
|
|
* Chicago: 7,000,000
|
|
|
|
* Japan
|
|
|
|
* Tokyo: 33,000,000
|
|
|
|
You can use the ``{% regroup %}`` tag to group the list of cities by country.
|
|
The following snippet of template code would accomplish this::
|
|
|
|
{% regroup cities by country as country_list %}
|
|
|
|
<ul>
|
|
{% for country in country_list %}
|
|
<li>{{ country.grouper }}
|
|
<ul>
|
|
{% for city in country.list %}
|
|
<li>{{ city.name }}: {{ city.population }}</li>
|
|
{% endfor %}
|
|
</ul>
|
|
</li>
|
|
{% endfor %}
|
|
</ul>
|
|
|
|
Let's walk through this example. ``{% regroup %}`` takes three arguments: the
|
|
list you want to regroup, the attribute to group by, and the name of the
|
|
resulting list. Here, we're regrouping the ``cities`` list by the ``country``
|
|
attribute and calling the result ``country_list``.
|
|
|
|
``{% regroup %}`` produces a list (in this case, ``country_list``) of
|
|
**group objects**. Group objects are instances of
|
|
:py:func:`~collections.namedtuple` with two fields:
|
|
|
|
* ``grouper`` -- the item that was grouped by (e.g., the string "India" or
|
|
"Japan").
|
|
* ``list`` -- a list of all items in this group (e.g., a list of all cities
|
|
with country='India').
|
|
|
|
Because ``{% regroup %}`` produces :py:func:`~collections.namedtuple` objects,
|
|
you can also write the previous example as::
|
|
|
|
{% regroup cities by country as country_list %}
|
|
|
|
<ul>
|
|
{% for country, local_cities in country_list %}
|
|
<li>{{ country }}
|
|
<ul>
|
|
{% for city in local_cities %}
|
|
<li>{{ city.name }}: {{ city.population }}</li>
|
|
{% endfor %}
|
|
</ul>
|
|
</li>
|
|
{% endfor %}
|
|
</ul>
|
|
|
|
Note that ``{% regroup %}`` does not order its input! Our example relies on
|
|
the fact that the ``cities`` list was ordered by ``country`` in the first place.
|
|
If the ``cities`` list did *not* order its members by ``country``, the
|
|
regrouping would naively display more than one group for a single country. For
|
|
example, say the ``cities`` list was set to this (note that the countries are not
|
|
grouped together):
|
|
|
|
.. code-block:: python
|
|
|
|
cities = [
|
|
{'name': 'Mumbai', 'population': '19,000,000', 'country': 'India'},
|
|
{'name': 'New York', 'population': '20,000,000', 'country': 'USA'},
|
|
{'name': 'Calcutta', 'population': '15,000,000', 'country': 'India'},
|
|
{'name': 'Chicago', 'population': '7,000,000', 'country': 'USA'},
|
|
{'name': 'Tokyo', 'population': '33,000,000', 'country': 'Japan'},
|
|
]
|
|
|
|
With this input for ``cities``, the example ``{% regroup %}`` template code
|
|
above would result in the following output:
|
|
|
|
* India
|
|
|
|
* Mumbai: 19,000,000
|
|
|
|
* USA
|
|
|
|
* New York: 20,000,000
|
|
|
|
* India
|
|
|
|
* Calcutta: 15,000,000
|
|
|
|
* USA
|
|
|
|
* Chicago: 7,000,000
|
|
|
|
* Japan
|
|
|
|
* Tokyo: 33,000,000
|
|
|
|
The easiest solution to this gotcha is to make sure in your view code that the
|
|
data is ordered according to how you want to display it.
|
|
|
|
Another solution is to sort the data in the template using the
|
|
:tfilter:`dictsort` filter, if your data is in a list of dictionaries::
|
|
|
|
{% regroup cities|dictsort:"country" by country as country_list %}
|
|
|
|
Grouping on other properties
|
|
~~~~~~~~~~~~~~~~~~~~~~~~~~~~
|
|
|
|
Any valid template lookup is a legal grouping attribute for the regroup
|
|
tag, including methods, attributes, dictionary keys and list items. For
|
|
example, if the "country" field is a foreign key to a class with
|
|
an attribute "description," you could use::
|
|
|
|
{% regroup cities by country.description as country_list %}
|
|
|
|
Or, if ``country`` is a field with ``choices``, it will have a
|
|
:meth:`~django.db.models.Model.get_FOO_display` method available as an
|
|
attribute, allowing you to group on the display string rather than the
|
|
``choices`` key::
|
|
|
|
{% regroup cities by get_country_display as country_list %}
|
|
|
|
``{{ country.grouper }}`` will now display the value fields from the
|
|
``choices`` set rather than the keys.
|
|
|
|
.. templatetag:: resetcycle
|
|
|
|
``resetcycle``
|
|
--------------
|
|
|
|
Resets a previous `cycle`_ so that it restarts from its first item at its next
|
|
encounter. Without arguments, ``{% resetcycle %}`` will reset the last
|
|
``{% cycle %}`` defined in the template.
|
|
|
|
Example usage::
|
|
|
|
{% for coach in coach_list %}
|
|
<h1>{{ coach.name }}</h1>
|
|
{% for athlete in coach.athlete_set.all %}
|
|
<p class="{% cycle 'odd' 'even' %}">{{ athlete.name }}</p>
|
|
{% endfor %}
|
|
{% resetcycle %}
|
|
{% endfor %}
|
|
|
|
This example would return this HTML::
|
|
|
|
<h1>José Mourinho</h1>
|
|
<p class="odd">Thibaut Courtois</p>
|
|
<p class="even">John Terry</p>
|
|
<p class="odd">Eden Hazard</p>
|
|
|
|
<h1>Carlo Ancelotti</h1>
|
|
<p class="odd">Manuel Neuer</p>
|
|
<p class="even">Thomas Müller</p>
|
|
|
|
Notice how the first block ends with ``class="odd"`` and the new one starts
|
|
with ``class="odd"``. Without the ``{% resetcycle %}`` tag, the second block
|
|
would start with ``class="even"``.
|
|
|
|
You can also reset named cycle tags::
|
|
|
|
{% for item in list %}
|
|
<p class="{% cycle 'odd' 'even' as stripe %} {% cycle 'major' 'minor' 'minor' 'minor' 'minor' as tick %}">
|
|
{{ item.data }}
|
|
</p>
|
|
{% ifchanged item.category %}
|
|
<h1>{{ item.category }}</h1>
|
|
{% if not forloop.first %}{% resetcycle tick %}{% endif %}
|
|
{% endifchanged %}
|
|
{% endfor %}
|
|
|
|
In this example, we have both the alternating odd/even rows and a "major" row
|
|
every fifth row. Only the five-row cycle is reset when a category changes.
|
|
|
|
.. templatetag:: spaceless
|
|
|
|
``spaceless``
|
|
-------------
|
|
|
|
Removes whitespace between HTML tags. This includes tab
|
|
characters and newlines.
|
|
|
|
Example usage::
|
|
|
|
{% spaceless %}
|
|
<p>
|
|
<a href="foo/">Foo</a>
|
|
</p>
|
|
{% endspaceless %}
|
|
|
|
This example would return this HTML::
|
|
|
|
<p><a href="foo/">Foo</a></p>
|
|
|
|
Only space between *tags* is removed -- not space between tags and text. In
|
|
this example, the space around ``Hello`` won't be stripped::
|
|
|
|
{% spaceless %}
|
|
<strong>
|
|
Hello
|
|
</strong>
|
|
{% endspaceless %}
|
|
|
|
.. templatetag:: templatetag
|
|
|
|
``templatetag``
|
|
---------------
|
|
|
|
Outputs one of the syntax characters used to compose template tags.
|
|
|
|
Since the template system has no concept of "escaping", to display one of the
|
|
bits used in template tags, you must use the ``{% templatetag %}`` tag.
|
|
|
|
The argument tells which template bit to output:
|
|
|
|
================== =======
|
|
Argument Outputs
|
|
================== =======
|
|
``openblock`` ``{%``
|
|
``closeblock`` ``%}``
|
|
``openvariable`` ``{{``
|
|
``closevariable`` ``}}``
|
|
``openbrace`` ``{``
|
|
``closebrace`` ``}``
|
|
``opencomment`` ``{#``
|
|
``closecomment`` ``#}``
|
|
================== =======
|
|
|
|
Sample usage::
|
|
|
|
{% templatetag openblock %} url 'entry_list' {% templatetag closeblock %}
|
|
|
|
.. templatetag:: url
|
|
|
|
``url``
|
|
-------
|
|
|
|
Returns an absolute path reference (a URL without the domain name) matching a
|
|
given view and optional parameters. Any special characters in the resulting
|
|
path will be encoded using :func:`~django.utils.encoding.iri_to_uri`.
|
|
|
|
This is a way to output links without violating the DRY principle by having to
|
|
hard-code URLs in your templates::
|
|
|
|
{% url 'some-url-name' v1 v2 %}
|
|
|
|
The first argument is a :ref:`URL pattern name <naming-url-patterns>`. It can
|
|
be a quoted literal or any other context variable. Additional arguments are
|
|
optional and should be space-separated values that will be used as arguments in
|
|
the URL. The example above shows passing positional arguments. Alternatively
|
|
you may use keyword syntax::
|
|
|
|
{% url 'some-url-name' arg1=v1 arg2=v2 %}
|
|
|
|
Do not mix both positional and keyword syntax in a single call. All arguments
|
|
required by the URLconf should be present.
|
|
|
|
For example, suppose you have a view, ``app_views.client``, whose URLconf
|
|
takes a client ID (here, ``client()`` is a method inside the views file
|
|
``app_views.py``). The URLconf line might look like this:
|
|
|
|
.. code-block:: python
|
|
|
|
path('client/<int:id>/', app_views.client, name='app-views-client')
|
|
|
|
If this app's URLconf is included into the project's URLconf under a path
|
|
such as this:
|
|
|
|
.. code-block:: python
|
|
|
|
path('clients/', include('project_name.app_name.urls'))
|
|
|
|
...then, in a template, you can create a link to this view like this::
|
|
|
|
{% url 'app-views-client' client.id %}
|
|
|
|
The template tag will output the string ``/clients/client/123/``.
|
|
|
|
Note that if the URL you're reversing doesn't exist, you'll get an
|
|
:exc:`~django.urls.NoReverseMatch` exception raised, which will cause your
|
|
site to display an error page.
|
|
|
|
If you'd like to retrieve a URL without displaying it, you can use a slightly
|
|
different call::
|
|
|
|
{% url 'some-url-name' arg arg2 as the_url %}
|
|
|
|
<a href="{{ the_url }}">I'm linking to {{ the_url }}</a>
|
|
|
|
The scope of the variable created by the ``as var`` syntax is the
|
|
``{% block %}`` in which the ``{% url %}`` tag appears.
|
|
|
|
This ``{% url ... as var %}`` syntax will *not* cause an error if the view is
|
|
missing. In practice you'll use this to link to views that are optional::
|
|
|
|
{% url 'some-url-name' as the_url %}
|
|
{% if the_url %}
|
|
<a href="{{ the_url }}">Link to optional stuff</a>
|
|
{% endif %}
|
|
|
|
If you'd like to retrieve a namespaced URL, specify the fully qualified name::
|
|
|
|
{% url 'myapp:view-name' %}
|
|
|
|
This will follow the normal :ref:`namespaced URL resolution strategy
|
|
<topics-http-reversing-url-namespaces>`, including using any hints provided
|
|
by the context as to the current application.
|
|
|
|
.. warning::
|
|
|
|
Don't forget to put quotes around the URL pattern ``name``, otherwise the
|
|
value will be interpreted as a context variable!
|
|
|
|
.. templatetag:: verbatim
|
|
|
|
``verbatim``
|
|
------------
|
|
|
|
Stops the template engine from rendering the contents of this block tag.
|
|
|
|
A common use is to allow a JavaScript template layer that collides with
|
|
Django's syntax. For example::
|
|
|
|
{% verbatim %}
|
|
{{if dying}}Still alive.{{/if}}
|
|
{% endverbatim %}
|
|
|
|
You can also designate a specific closing tag, allowing the use of
|
|
``{% endverbatim %}`` as part of the unrendered contents::
|
|
|
|
{% verbatim myblock %}
|
|
Avoid template rendering via the {% verbatim %}{% endverbatim %} block.
|
|
{% endverbatim myblock %}
|
|
|
|
.. templatetag:: widthratio
|
|
|
|
``widthratio``
|
|
--------------
|
|
|
|
For creating bar charts and such, this tag calculates the ratio of a given
|
|
value to a maximum value, and then applies that ratio to a constant.
|
|
|
|
For example::
|
|
|
|
<img src="bar.png" alt="Bar"
|
|
height="10" width="{% widthratio this_value max_value max_width %}">
|
|
|
|
If ``this_value`` is 175, ``max_value`` is 200, and ``max_width`` is 100, the
|
|
image in the above example will be 88 pixels wide
|
|
(because 175/200 = .875; .875 * 100 = 87.5 which is rounded up to 88).
|
|
|
|
In some cases you might want to capture the result of ``widthratio`` in a
|
|
variable. It can be useful, for instance, in a :ttag:`blocktranslate` like this::
|
|
|
|
{% widthratio this_value max_value max_width as width %}
|
|
{% blocktranslate %}The width is: {{ width }}{% endblocktranslate %}
|
|
|
|
.. templatetag:: with
|
|
|
|
``with``
|
|
--------
|
|
|
|
Caches a complex variable under a simpler name. This is useful when accessing
|
|
an "expensive" method (e.g., one that hits the database) multiple times.
|
|
|
|
For example::
|
|
|
|
{% with total=business.employees.count %}
|
|
{{ total }} employee{{ total|pluralize }}
|
|
{% endwith %}
|
|
|
|
The populated variable (in the example above, ``total``) is only available
|
|
between the ``{% with %}`` and ``{% endwith %}`` tags.
|
|
|
|
You can assign more than one context variable::
|
|
|
|
{% with alpha=1 beta=2 %}
|
|
...
|
|
{% endwith %}
|
|
|
|
.. note:: The previous more verbose format is still supported:
|
|
``{% with business.employees.count as total %}``
|
|
|
|
.. _ref-templates-builtins-filters:
|
|
|
|
Built-in filter reference
|
|
=========================
|
|
|
|
.. templatefilter:: add
|
|
|
|
``add``
|
|
-------
|
|
|
|
Adds the argument to the value.
|
|
|
|
For example::
|
|
|
|
{{ value|add:"2" }}
|
|
|
|
If ``value`` is ``4``, then the output will be ``6``.
|
|
|
|
This filter will first try to coerce both values to integers. If this fails,
|
|
it'll attempt to add the values together anyway. This will work on some data
|
|
types (strings, list, etc.) and fail on others. If it fails, the result will
|
|
be an empty string.
|
|
|
|
For example, if we have::
|
|
|
|
{{ first|add:second }}
|
|
|
|
and ``first`` is ``[1, 2, 3]`` and ``second`` is ``[4, 5, 6]``, then the
|
|
output will be ``[1, 2, 3, 4, 5, 6]``.
|
|
|
|
.. warning::
|
|
|
|
Strings that can be coerced to integers will be **summed**, not
|
|
concatenated, as in the first example above.
|
|
|
|
.. templatefilter:: addslashes
|
|
|
|
``addslashes``
|
|
--------------
|
|
|
|
Adds slashes before quotes. Useful for escaping strings in CSV, for example.
|
|
|
|
For example::
|
|
|
|
{{ value|addslashes }}
|
|
|
|
If ``value`` is ``"I'm using Django"``, the output will be
|
|
``"I\'m using Django"``.
|
|
|
|
.. templatefilter:: capfirst
|
|
|
|
``capfirst``
|
|
------------
|
|
|
|
Capitalizes the first character of the value. If the first character is not
|
|
a letter, this filter has no effect.
|
|
|
|
For example::
|
|
|
|
{{ value|capfirst }}
|
|
|
|
If ``value`` is ``"django"``, the output will be ``"Django"``.
|
|
|
|
.. templatefilter:: center
|
|
|
|
``center``
|
|
----------
|
|
|
|
Centers the value in a field of a given width.
|
|
|
|
For example::
|
|
|
|
"{{ value|center:"15" }}"
|
|
|
|
If ``value`` is ``"Django"``, the output will be ``" Django "``.
|
|
|
|
.. templatefilter:: cut
|
|
|
|
``cut``
|
|
-------
|
|
|
|
Removes all values of arg from the given string.
|
|
|
|
For example::
|
|
|
|
{{ value|cut:" " }}
|
|
|
|
If ``value`` is ``"String with spaces"``, the output will be
|
|
``"Stringwithspaces"``.
|
|
|
|
.. templatefilter:: date
|
|
|
|
``date``
|
|
--------
|
|
|
|
Formats a date according to the given format.
|
|
|
|
Uses a similar format as PHP's ``date()`` function (https://php.net/date)
|
|
with some differences.
|
|
|
|
.. note::
|
|
These format characters are not used in Django outside of templates. They
|
|
were designed to be compatible with PHP to ease transitioning for designers.
|
|
|
|
.. _date-and-time-formatting-specifiers:
|
|
|
|
Available format strings:
|
|
|
|
================ ======================================== =====================
|
|
Format character Description Example output
|
|
================ ======================================== =====================
|
|
**Day**
|
|
``d`` Day of the month, 2 digits with ``'01'`` to ``'31'``
|
|
leading zeros.
|
|
``j`` Day of the month without leading ``'1'`` to ``'31'``
|
|
zeros.
|
|
``D`` Day of the week, textual, 3 letters. ``'Fri'``
|
|
``l`` Day of the week, textual, long. ``'Friday'``
|
|
``S`` English ordinal suffix for day of the ``'st'``, ``'nd'``, ``'rd'`` or ``'th'``
|
|
month, 2 characters.
|
|
``w`` Day of the week, digits without ``'0'`` (Sunday) to ``'6'`` (Saturday)
|
|
leading zeros.
|
|
``z`` Day of the year. ``1`` to ``366``
|
|
**Week**
|
|
``W`` ISO-8601 week number of year, with ``1``, ``53``
|
|
weeks starting on Monday.
|
|
**Month**
|
|
``m`` Month, 2 digits with leading zeros. ``'01'`` to ``'12'``
|
|
``n`` Month without leading zeros. ``'1'`` to ``'12'``
|
|
``M`` Month, textual, 3 letters. ``'Jan'``
|
|
``b`` Month, textual, 3 letters, lowercase. ``'jan'``
|
|
``E`` Month, locale specific alternative
|
|
representation usually used for long
|
|
date representation. ``'listopada'`` (for Polish locale, as opposed to ``'Listopad'``)
|
|
``F`` Month, textual, long. ``'January'``
|
|
``N`` Month abbreviation in Associated Press ``'Jan.'``, ``'Feb.'``, ``'March'``, ``'May'``
|
|
style. Proprietary extension.
|
|
``t`` Number of days in the given month. ``28`` to ``31``
|
|
**Year**
|
|
``y`` Year, 2 digits with leading zeros. ``'00'`` to ``'99'``
|
|
``Y`` Year, 4 digits with leading zeros. ``'0001'``, ..., ``'1999'``, ..., ``'9999'``
|
|
``L`` Boolean for whether it's a leap year. ``True`` or ``False``
|
|
``o`` ISO-8601 week-numbering year, ``'1999'``
|
|
corresponding to the ISO-8601 week
|
|
number (W) which uses leap weeks. See Y
|
|
for the more common year format.
|
|
**Time**
|
|
``g`` Hour, 12-hour format without leading ``'1'`` to ``'12'``
|
|
zeros.
|
|
``G`` Hour, 24-hour format without leading ``'0'`` to ``'23'``
|
|
zeros.
|
|
``h`` Hour, 12-hour format. ``'01'`` to ``'12'``
|
|
``H`` Hour, 24-hour format. ``'00'`` to ``'23'``
|
|
``i`` Minutes. ``'00'`` to ``'59'``
|
|
``s`` Seconds, 2 digits with leading zeros. ``'00'`` to ``'59'``
|
|
``u`` Microseconds. ``000000`` to ``999999``
|
|
``a`` ``'a.m.'`` or ``'p.m.'`` (Note that ``'a.m.'``
|
|
this is slightly different than PHP's
|
|
output, because this includes periods
|
|
to match Associated Press style.)
|
|
``A`` ``'AM'`` or ``'PM'``. ``'AM'``
|
|
``f`` Time, in 12-hour hours and minutes, ``'1'``, ``'1:30'``
|
|
with minutes left off if they're zero.
|
|
Proprietary extension.
|
|
``P`` Time, in 12-hour hours, minutes and ``'1 a.m.'``, ``'1:30 p.m.'``, ``'midnight'``, ``'noon'``, ``'12:30 p.m.'``
|
|
'a.m.'/'p.m.', with minutes left off
|
|
if they're zero and the special-case
|
|
strings 'midnight' and 'noon' if
|
|
appropriate. Proprietary extension.
|
|
**Timezone**
|
|
``e`` Timezone name. Could be in any format,
|
|
or might return an empty string, ``''``, ``'GMT'``, ``'-500'``, ``'US/Eastern'``, etc.
|
|
depending on the datetime.
|
|
``I`` Daylight Savings Time, whether it's ``'1'`` or ``'0'``
|
|
in effect or not.
|
|
``O`` Difference to Greenwich time in hours. ``'+0200'``
|
|
``T`` Time zone of this machine. ``'EST'``, ``'MDT'``
|
|
``Z`` Time zone offset in seconds. The ``-43200`` to ``43200``
|
|
offset for timezones west of UTC is
|
|
always negative, and for those east of
|
|
UTC is always positive.
|
|
**Date/Time**
|
|
``c`` ISO 8601 format. (Note: unlike other ``2008-01-02T10:30:00.000123+02:00``,
|
|
formatters, such as "Z", "O" or "r", or ``2008-01-02T10:30:00.000123`` if the datetime is naive
|
|
the "c" formatter will not add timezone
|
|
offset if value is a naive datetime
|
|
(see :class:`datetime.tzinfo`).
|
|
``r`` :rfc:`RFC 5322 <5322#section-3.3>` ``'Thu, 21 Dec 2000 16:01:07 +0200'``
|
|
formatted date.
|
|
``U`` Seconds since the Unix Epoch
|
|
(January 1 1970 00:00:00 UTC).
|
|
================ ======================================== =====================
|
|
|
|
For example::
|
|
|
|
{{ value|date:"D d M Y" }}
|
|
|
|
If ``value`` is a :py:class:`~datetime.datetime` object (e.g., the result of
|
|
``datetime.datetime.now()``), the output will be the string
|
|
``'Wed 09 Jan 2008'``.
|
|
|
|
The format passed can be one of the predefined ones :setting:`DATE_FORMAT`,
|
|
:setting:`DATETIME_FORMAT`, :setting:`SHORT_DATE_FORMAT` or
|
|
:setting:`SHORT_DATETIME_FORMAT`, or a custom format that uses the format
|
|
specifiers shown in the table above. Note that predefined formats may vary
|
|
depending on the current locale.
|
|
|
|
Assuming that :setting:`USE_L10N` is ``True`` and :setting:`LANGUAGE_CODE` is,
|
|
for example, ``"es"``, then for::
|
|
|
|
{{ value|date:"SHORT_DATE_FORMAT" }}
|
|
|
|
the output would be the string ``"09/01/2008"`` (the ``"SHORT_DATE_FORMAT"``
|
|
format specifier for the ``es`` locale as shipped with Django is ``"d/m/Y"``).
|
|
|
|
When used without a format string, the ``DATE_FORMAT`` format specifier is
|
|
used. Assuming the same settings as the previous example::
|
|
|
|
{{ value|date }}
|
|
|
|
outputs ``9 de Enero de 2008`` (the ``DATE_FORMAT`` format specifier for the
|
|
``es`` locale is ``r'j \d\e F \d\e Y'``). Both "d" and "e" are
|
|
backslash-escaped, because otherwise each is a format string that displays the
|
|
day and the timezone name, respectively.
|
|
|
|
You can combine ``date`` with the :tfilter:`time` filter to render a full
|
|
representation of a ``datetime`` value. E.g.::
|
|
|
|
{{ value|date:"D d M Y" }} {{ value|time:"H:i" }}
|
|
|
|
.. templatefilter:: default
|
|
|
|
``default``
|
|
-----------
|
|
|
|
If value evaluates to ``False``, uses the given default. Otherwise, uses the
|
|
value.
|
|
|
|
For example::
|
|
|
|
{{ value|default:"nothing" }}
|
|
|
|
If ``value`` is ``""`` (the empty string), the output will be ``nothing``.
|
|
|
|
.. templatefilter:: default_if_none
|
|
|
|
``default_if_none``
|
|
-------------------
|
|
|
|
If (and only if) value is ``None``, uses the given default. Otherwise, uses the
|
|
value.
|
|
|
|
Note that if an empty string is given, the default value will *not* be used.
|
|
Use the :tfilter:`default` filter if you want to fallback for empty strings.
|
|
|
|
For example::
|
|
|
|
{{ value|default_if_none:"nothing" }}
|
|
|
|
If ``value`` is ``None``, the output will be ``nothing``.
|
|
|
|
.. templatefilter:: dictsort
|
|
|
|
``dictsort``
|
|
------------
|
|
|
|
Takes a list of dictionaries and returns that list sorted by the key given in
|
|
the argument.
|
|
|
|
For example::
|
|
|
|
{{ value|dictsort:"name" }}
|
|
|
|
If ``value`` is:
|
|
|
|
.. code-block:: python
|
|
|
|
[
|
|
{'name': 'zed', 'age': 19},
|
|
{'name': 'amy', 'age': 22},
|
|
{'name': 'joe', 'age': 31},
|
|
]
|
|
|
|
then the output would be:
|
|
|
|
.. code-block:: python
|
|
|
|
[
|
|
{'name': 'amy', 'age': 22},
|
|
{'name': 'joe', 'age': 31},
|
|
{'name': 'zed', 'age': 19},
|
|
]
|
|
|
|
You can also do more complicated things like::
|
|
|
|
{% for book in books|dictsort:"author.age" %}
|
|
* {{ book.title }} ({{ book.author.name }})
|
|
{% endfor %}
|
|
|
|
If ``books`` is:
|
|
|
|
.. code-block:: python
|
|
|
|
[
|
|
{'title': '1984', 'author': {'name': 'George', 'age': 45}},
|
|
{'title': 'Timequake', 'author': {'name': 'Kurt', 'age': 75}},
|
|
{'title': 'Alice', 'author': {'name': 'Lewis', 'age': 33}},
|
|
]
|
|
|
|
then the output would be::
|
|
|
|
* Alice (Lewis)
|
|
* 1984 (George)
|
|
* Timequake (Kurt)
|
|
|
|
``dictsort`` can also order a list of lists (or any other object implementing
|
|
``__getitem__()``) by elements at specified index. For example::
|
|
|
|
{{ value|dictsort:0 }}
|
|
|
|
If ``value`` is:
|
|
|
|
.. code-block:: python
|
|
|
|
[
|
|
('a', '42'),
|
|
('c', 'string'),
|
|
('b', 'foo'),
|
|
]
|
|
|
|
then the output would be:
|
|
|
|
.. code-block:: python
|
|
|
|
[
|
|
('a', '42'),
|
|
('b', 'foo'),
|
|
('c', 'string'),
|
|
]
|
|
|
|
You must pass the index as an integer rather than a string. The following
|
|
produce empty output::
|
|
|
|
{{ values|dictsort:"0" }}
|
|
|
|
.. templatefilter:: dictsortreversed
|
|
|
|
``dictsortreversed``
|
|
--------------------
|
|
|
|
Takes a list of dictionaries and returns that list sorted in reverse order by
|
|
the key given in the argument. This works exactly the same as the above filter,
|
|
but the returned value will be in reverse order.
|
|
|
|
.. templatefilter:: divisibleby
|
|
|
|
``divisibleby``
|
|
---------------
|
|
|
|
Returns ``True`` if the value is divisible by the argument.
|
|
|
|
For example::
|
|
|
|
{{ value|divisibleby:"3" }}
|
|
|
|
If ``value`` is ``21``, the output would be ``True``.
|
|
|
|
.. templatefilter:: escape
|
|
|
|
``escape``
|
|
----------
|
|
|
|
Escapes a string's HTML. Specifically, it makes these replacements:
|
|
|
|
* ``<`` is converted to ``<``
|
|
* ``>`` is converted to ``>``
|
|
* ``'`` (single quote) is converted to ``'``
|
|
* ``"`` (double quote) is converted to ``"``
|
|
* ``&`` is converted to ``&``
|
|
|
|
Applying ``escape`` to a variable that would normally have auto-escaping
|
|
applied to the result will only result in one round of escaping being done. So
|
|
it is safe to use this function even in auto-escaping environments. If you want
|
|
multiple escaping passes to be applied, use the :tfilter:`force_escape` filter.
|
|
|
|
For example, you can apply ``escape`` to fields when :ttag:`autoescape` is off::
|
|
|
|
{% autoescape off %}
|
|
{{ title|escape }}
|
|
{% endautoescape %}
|
|
|
|
.. templatefilter:: escapejs
|
|
|
|
``escapejs``
|
|
------------
|
|
|
|
Escapes characters for use in JavaScript strings. This does *not* make the
|
|
string safe for use in HTML or JavaScript template literals, but does protect
|
|
you from syntax errors when using templates to generate JavaScript/JSON.
|
|
|
|
For example::
|
|
|
|
{{ value|escapejs }}
|
|
|
|
If ``value`` is ``"testing\r\njavascript 'string\" <b>escaping</b>"``,
|
|
the output will be ``"testing\\u000D\\u000Ajavascript \\u0027string\\u0022 \\u003Cb\\u003Eescaping\\u003C/b\\u003E"``.
|
|
|
|
.. templatefilter:: filesizeformat
|
|
|
|
``filesizeformat``
|
|
------------------
|
|
|
|
Formats the value like a 'human-readable' file size (i.e. ``'13 KB'``,
|
|
``'4.1 MB'``, ``'102 bytes'``, etc.).
|
|
|
|
For example::
|
|
|
|
{{ value|filesizeformat }}
|
|
|
|
If ``value`` is 123456789, the output would be ``117.7 MB``.
|
|
|
|
.. admonition:: File sizes and SI units
|
|
|
|
Strictly speaking, ``filesizeformat`` does not conform to the International
|
|
System of Units which recommends using KiB, MiB, GiB, etc. when byte sizes
|
|
are calculated in powers of 1024 (which is the case here). Instead, Django
|
|
uses traditional unit names (KB, MB, GB, etc.) corresponding to names that
|
|
are more commonly used.
|
|
|
|
.. templatefilter:: first
|
|
|
|
``first``
|
|
---------
|
|
|
|
Returns the first item in a list.
|
|
|
|
For example::
|
|
|
|
{{ value|first }}
|
|
|
|
If ``value`` is the list ``['a', 'b', 'c']``, the output will be ``'a'``.
|
|
|
|
.. templatefilter:: floatformat
|
|
|
|
``floatformat``
|
|
---------------
|
|
|
|
When used without an argument, rounds a floating-point number to one decimal
|
|
place -- but only if there's a decimal part to be displayed. For example:
|
|
|
|
============ =========================== ========
|
|
``value`` Template Output
|
|
============ =========================== ========
|
|
``34.23234`` ``{{ value|floatformat }}`` ``34.2``
|
|
``34.00000`` ``{{ value|floatformat }}`` ``34``
|
|
``34.26000`` ``{{ value|floatformat }}`` ``34.3``
|
|
============ =========================== ========
|
|
|
|
If used with a numeric integer argument, ``floatformat`` rounds a number to
|
|
that many decimal places. For example:
|
|
|
|
============ ============================= ==========
|
|
``value`` Template Output
|
|
============ ============================= ==========
|
|
``34.23234`` ``{{ value|floatformat:3 }}`` ``34.232``
|
|
``34.00000`` ``{{ value|floatformat:3 }}`` ``34.000``
|
|
``34.26000`` ``{{ value|floatformat:3 }}`` ``34.260``
|
|
============ ============================= ==========
|
|
|
|
Particularly useful is passing 0 (zero) as the argument which will round the
|
|
float to the nearest integer.
|
|
|
|
============ ================================ ==========
|
|
``value`` Template Output
|
|
============ ================================ ==========
|
|
``34.23234`` ``{{ value|floatformat:"0" }}`` ``34``
|
|
``34.00000`` ``{{ value|floatformat:"0" }}`` ``34``
|
|
``39.56000`` ``{{ value|floatformat:"0" }}`` ``40``
|
|
============ ================================ ==========
|
|
|
|
If the argument passed to ``floatformat`` is negative, it will round a number
|
|
to that many decimal places -- but only if there's a decimal part to be
|
|
displayed. For example:
|
|
|
|
============ ================================ ==========
|
|
``value`` Template Output
|
|
============ ================================ ==========
|
|
``34.23234`` ``{{ value|floatformat:"-3" }}`` ``34.232``
|
|
``34.00000`` ``{{ value|floatformat:"-3" }}`` ``34``
|
|
``34.26000`` ``{{ value|floatformat:"-3" }}`` ``34.260``
|
|
============ ================================ ==========
|
|
|
|
If the argument passed to ``floatformat`` has the ``g`` suffix, it will force
|
|
grouping by the :setting:`THOUSAND_SEPARATOR` for the active locale. For
|
|
example, when the active locale is ``en`` (English):
|
|
|
|
============ ================================= =============
|
|
``value`` Template Output
|
|
============ ================================= =============
|
|
``34232.34`` ``{{ value|floatformat:"2g" }}`` ``34,232.34``
|
|
``34232.06`` ``{{ value|floatformat:"g" }}`` ``34,232.1``
|
|
``34232.00`` ``{{ value|floatformat:"-3g" }}`` ``34,232``
|
|
============ ================================= =============
|
|
|
|
Using ``floatformat`` with no argument is equivalent to using ``floatformat``
|
|
with an argument of ``-1``.
|
|
|
|
.. versionchanged:: 3.2
|
|
|
|
The ``g`` suffix to force grouping by thousand separators was added.
|
|
|
|
.. templatefilter:: force_escape
|
|
|
|
``force_escape``
|
|
----------------
|
|
|
|
Applies HTML escaping to a string (see the :tfilter:`escape` filter for
|
|
details). This filter is applied *immediately* and returns a new, escaped
|
|
string. This is useful in the rare cases where you need multiple escaping or
|
|
want to apply other filters to the escaped results. Normally, you want to use
|
|
the :tfilter:`escape` filter.
|
|
|
|
For example, if you want to catch the ``<p>`` HTML elements created by
|
|
the :tfilter:`linebreaks` filter::
|
|
|
|
{% autoescape off %}
|
|
{{ body|linebreaks|force_escape }}
|
|
{% endautoescape %}
|
|
|
|
.. templatefilter:: get_digit
|
|
|
|
``get_digit``
|
|
-------------
|
|
|
|
Given a whole number, returns the requested digit, where 1 is the right-most
|
|
digit, 2 is the second-right-most digit, etc. Returns the original value for
|
|
invalid input (if input or argument is not an integer, or if argument is less
|
|
than 1). Otherwise, output is always an integer.
|
|
|
|
For example::
|
|
|
|
{{ value|get_digit:"2" }}
|
|
|
|
If ``value`` is ``123456789``, the output will be ``8``.
|
|
|
|
.. templatefilter:: iriencode
|
|
|
|
``iriencode``
|
|
-------------
|
|
|
|
Converts an IRI (Internationalized Resource Identifier) to a string that is
|
|
suitable for including in a URL. This is necessary if you're trying to use
|
|
strings containing non-ASCII characters in a URL.
|
|
|
|
It's safe to use this filter on a string that has already gone through the
|
|
:tfilter:`urlencode` filter.
|
|
|
|
For example::
|
|
|
|
{{ value|iriencode }}
|
|
|
|
If ``value`` is ``"?test=1&me=2"``, the output will be ``"?test=1&me=2"``.
|
|
|
|
.. templatefilter:: join
|
|
|
|
``join``
|
|
--------
|
|
|
|
Joins a list with a string, like Python's ``str.join(list)``
|
|
|
|
For example::
|
|
|
|
{{ value|join:" // " }}
|
|
|
|
If ``value`` is the list ``['a', 'b', 'c']``, the output will be the string
|
|
``"a // b // c"``.
|
|
|
|
.. templatefilter:: json_script
|
|
|
|
``json_script``
|
|
---------------
|
|
|
|
Safely outputs a Python object as JSON, wrapped in a ``<script>`` tag, ready
|
|
for use with JavaScript.
|
|
|
|
**Argument:** HTML "id" of the ``<script>`` tag.
|
|
|
|
For example::
|
|
|
|
{{ value|json_script:"hello-data" }}
|
|
|
|
If ``value`` is the dictionary ``{'hello': 'world'}``, the output will be:
|
|
|
|
.. code-block:: html
|
|
|
|
<script id="hello-data" type="application/json">{"hello": "world"}</script>
|
|
|
|
The resulting data can be accessed in JavaScript like this:
|
|
|
|
.. code-block:: javascript
|
|
|
|
const value = JSON.parse(document.getElementById('hello-data').textContent);
|
|
|
|
XSS attacks are mitigated by escaping the characters "<", ">" and "&". For
|
|
example if ``value`` is ``{'hello': 'world</script>&'}``, the output is:
|
|
|
|
.. code-block:: html
|
|
|
|
<script id="hello-data" type="application/json">{"hello": "world\\u003C/script\\u003E\\u0026amp;"}</script>
|
|
|
|
This is compatible with a strict Content Security Policy that prohibits in-page
|
|
script execution. It also maintains a clean separation between passive data and
|
|
executable code.
|
|
|
|
.. templatefilter:: last
|
|
|
|
``last``
|
|
--------
|
|
|
|
Returns the last item in a list.
|
|
|
|
For example::
|
|
|
|
{{ value|last }}
|
|
|
|
If ``value`` is the list ``['a', 'b', 'c', 'd']``, the output will be the
|
|
string ``"d"``.
|
|
|
|
.. templatefilter:: length
|
|
|
|
``length``
|
|
----------
|
|
|
|
Returns the length of the value. This works for both strings and lists.
|
|
|
|
For example::
|
|
|
|
{{ value|length }}
|
|
|
|
If ``value`` is ``['a', 'b', 'c', 'd']`` or ``"abcd"``, the output will be
|
|
``4``.
|
|
|
|
The filter returns ``0`` for an undefined variable.
|
|
|
|
.. templatefilter:: length_is
|
|
|
|
``length_is``
|
|
-------------
|
|
|
|
Returns ``True`` if the value's length is the argument, or ``False`` otherwise.
|
|
|
|
For example::
|
|
|
|
{{ value|length_is:"4" }}
|
|
|
|
If ``value`` is ``['a', 'b', 'c', 'd']`` or ``"abcd"``, the output will be
|
|
``True``.
|
|
|
|
.. templatefilter:: linebreaks
|
|
|
|
``linebreaks``
|
|
--------------
|
|
|
|
Replaces line breaks in plain text with appropriate HTML; a single
|
|
newline becomes an HTML line break (``<br>``) and a new line
|
|
followed by a blank line becomes a paragraph break (``</p>``).
|
|
|
|
For example::
|
|
|
|
{{ value|linebreaks }}
|
|
|
|
If ``value`` is ``Joel\nis a slug``, the output will be ``<p>Joel<br>is a
|
|
slug</p>``.
|
|
|
|
.. templatefilter:: linebreaksbr
|
|
|
|
``linebreaksbr``
|
|
----------------
|
|
|
|
Converts all newlines in a piece of plain text to HTML line breaks
|
|
(``<br>``).
|
|
|
|
For example::
|
|
|
|
{{ value|linebreaksbr }}
|
|
|
|
If ``value`` is ``Joel\nis a slug``, the output will be ``Joel<br>is a
|
|
slug``.
|
|
|
|
.. templatefilter:: linenumbers
|
|
|
|
``linenumbers``
|
|
---------------
|
|
|
|
Displays text with line numbers.
|
|
|
|
For example::
|
|
|
|
{{ value|linenumbers }}
|
|
|
|
If ``value`` is::
|
|
|
|
one
|
|
two
|
|
three
|
|
|
|
the output will be::
|
|
|
|
1. one
|
|
2. two
|
|
3. three
|
|
|
|
.. templatefilter:: ljust
|
|
|
|
``ljust``
|
|
---------
|
|
|
|
Left-aligns the value in a field of a given width.
|
|
|
|
**Argument:** field size
|
|
|
|
For example::
|
|
|
|
"{{ value|ljust:"10" }}"
|
|
|
|
If ``value`` is ``Django``, the output will be ``"Django "``.
|
|
|
|
.. templatefilter:: lower
|
|
|
|
``lower``
|
|
---------
|
|
|
|
Converts a string into all lowercase.
|
|
|
|
For example::
|
|
|
|
{{ value|lower }}
|
|
|
|
If ``value`` is ``Totally LOVING this Album!``, the output will be
|
|
``totally loving this album!``.
|
|
|
|
.. templatefilter:: make_list
|
|
|
|
``make_list``
|
|
-------------
|
|
|
|
Returns the value turned into a list. For a string, it's a list of characters.
|
|
For an integer, the argument is cast to a string before creating a list.
|
|
|
|
For example::
|
|
|
|
{{ value|make_list }}
|
|
|
|
If ``value`` is the string ``"Joel"``, the output would be the list
|
|
``['J', 'o', 'e', 'l']``. If ``value`` is ``123``, the output will be the
|
|
list ``['1', '2', '3']``.
|
|
|
|
.. templatefilter:: phone2numeric
|
|
|
|
``phone2numeric``
|
|
-----------------
|
|
|
|
Converts a phone number (possibly containing letters) to its numerical
|
|
equivalent.
|
|
|
|
The input doesn't have to be a valid phone number. This will happily convert
|
|
any string.
|
|
|
|
For example::
|
|
|
|
{{ value|phone2numeric }}
|
|
|
|
If ``value`` is ``800-COLLECT``, the output will be ``800-2655328``.
|
|
|
|
.. templatefilter:: pluralize
|
|
|
|
``pluralize``
|
|
-------------
|
|
|
|
Returns a plural suffix if the value is not ``1``, ``'1'``, or an object of
|
|
length 1. By default, this suffix is ``'s'``.
|
|
|
|
Example::
|
|
|
|
You have {{ num_messages }} message{{ num_messages|pluralize }}.
|
|
|
|
If ``num_messages`` is ``1``, the output will be ``You have 1 message.``
|
|
If ``num_messages`` is ``2`` the output will be ``You have 2 messages.``
|
|
|
|
For words that require a suffix other than ``'s'``, you can provide an alternate
|
|
suffix as a parameter to the filter.
|
|
|
|
Example::
|
|
|
|
You have {{ num_walruses }} walrus{{ num_walruses|pluralize:"es" }}.
|
|
|
|
For words that don't pluralize by simple suffix, you can specify both a
|
|
singular and plural suffix, separated by a comma.
|
|
|
|
Example::
|
|
|
|
You have {{ num_cherries }} cherr{{ num_cherries|pluralize:"y,ies" }}.
|
|
|
|
.. note:: Use :ttag:`blocktranslate` to pluralize translated strings.
|
|
|
|
.. templatefilter:: pprint
|
|
|
|
``pprint``
|
|
----------
|
|
|
|
A wrapper around :func:`pprint.pprint` -- for debugging, really.
|
|
|
|
.. templatefilter:: random
|
|
|
|
``random``
|
|
----------
|
|
|
|
Returns a random item from the given list.
|
|
|
|
For example::
|
|
|
|
{{ value|random }}
|
|
|
|
If ``value`` is the list ``['a', 'b', 'c', 'd']``, the output could be ``"b"``.
|
|
|
|
.. templatefilter:: rjust
|
|
|
|
``rjust``
|
|
---------
|
|
|
|
Right-aligns the value in a field of a given width.
|
|
|
|
**Argument:** field size
|
|
|
|
For example::
|
|
|
|
"{{ value|rjust:"10" }}"
|
|
|
|
If ``value`` is ``Django``, the output will be ``" Django"``.
|
|
|
|
.. templatefilter:: safe
|
|
|
|
``safe``
|
|
--------
|
|
|
|
Marks a string as not requiring further HTML escaping prior to output. When
|
|
autoescaping is off, this filter has no effect.
|
|
|
|
.. note::
|
|
|
|
If you are chaining filters, a filter applied after ``safe`` can
|
|
make the contents unsafe again. For example, the following code
|
|
prints the variable as is, unescaped::
|
|
|
|
{{ var|safe|escape }}
|
|
|
|
.. templatefilter:: safeseq
|
|
|
|
``safeseq``
|
|
-----------
|
|
|
|
Applies the :tfilter:`safe` filter to each element of a sequence. Useful in
|
|
conjunction with other filters that operate on sequences, such as
|
|
:tfilter:`join`. For example::
|
|
|
|
{{ some_list|safeseq|join:", " }}
|
|
|
|
You couldn't use the :tfilter:`safe` filter directly in this case, as it would
|
|
first convert the variable into a string, rather than working with the
|
|
individual elements of the sequence.
|
|
|
|
.. templatefilter:: slice
|
|
|
|
``slice``
|
|
---------
|
|
|
|
Returns a slice of the list.
|
|
|
|
Uses the same syntax as Python's list slicing. See
|
|
https://www.diveinto.org/python3/native-datatypes.html#slicinglists
|
|
for an introduction.
|
|
|
|
Example::
|
|
|
|
{{ some_list|slice:":2" }}
|
|
|
|
If ``some_list`` is ``['a', 'b', 'c']``, the output will be ``['a', 'b']``.
|
|
|
|
.. templatefilter:: slugify
|
|
|
|
``slugify``
|
|
-----------
|
|
|
|
Converts to ASCII. Converts spaces to hyphens. Removes characters that aren't
|
|
alphanumerics, underscores, or hyphens. Converts to lowercase. Also strips
|
|
leading and trailing whitespace.
|
|
|
|
For example::
|
|
|
|
{{ value|slugify }}
|
|
|
|
If ``value`` is ``"Joel is a slug"``, the output will be ``"joel-is-a-slug"``.
|
|
|
|
.. templatefilter:: stringformat
|
|
|
|
``stringformat``
|
|
----------------
|
|
|
|
Formats the variable according to the argument, a string formatting specifier.
|
|
This specifier uses the :ref:`old-string-formatting` syntax, with the exception
|
|
that the leading "%" is dropped.
|
|
|
|
For example::
|
|
|
|
{{ value|stringformat:"E" }}
|
|
|
|
If ``value`` is ``10``, the output will be ``1.000000E+01``.
|
|
|
|
.. templatefilter:: striptags
|
|
|
|
``striptags``
|
|
-------------
|
|
|
|
Makes all possible efforts to strip all [X]HTML tags.
|
|
|
|
For example::
|
|
|
|
{{ value|striptags }}
|
|
|
|
If ``value`` is ``"<b>Joel</b> <button>is</button> a <span>slug</span>"``, the
|
|
output will be ``"Joel is a slug"``.
|
|
|
|
.. admonition:: No safety guarantee
|
|
|
|
Note that ``striptags`` doesn't give any guarantee about its output being
|
|
HTML safe, particularly with non valid HTML input. So **NEVER** apply the
|
|
``safe`` filter to a ``striptags`` output. If you are looking for something
|
|
more robust, you can use the ``bleach`` Python library, notably its
|
|
`clean`_ method.
|
|
|
|
.. _clean: https://bleach.readthedocs.io/en/latest/clean.html
|
|
|
|
.. templatefilter:: time
|
|
|
|
``time``
|
|
--------
|
|
|
|
Formats a time according to the given format.
|
|
|
|
Given format can be the predefined one :setting:`TIME_FORMAT`, or a custom
|
|
format, same as the :tfilter:`date` filter. Note that the predefined format
|
|
is locale-dependent.
|
|
|
|
For example::
|
|
|
|
{{ value|time:"H:i" }}
|
|
|
|
If ``value`` is equivalent to ``datetime.datetime.now()``, the output will be
|
|
the string ``"01:23"``.
|
|
|
|
Note that you can backslash-escape a format string if you want to use the
|
|
"raw" value. In this example, both "h" and "m" are backslash-escaped, because
|
|
otherwise each is a format string that displays the hour and the month,
|
|
respectively::
|
|
|
|
{% value|time:"H\h i\m" %}
|
|
|
|
This would display as "01h 23m".
|
|
|
|
Another example:
|
|
|
|
Assuming that :setting:`USE_L10N` is ``True`` and :setting:`LANGUAGE_CODE` is,
|
|
for example, ``"de"``, then for::
|
|
|
|
{{ value|time:"TIME_FORMAT" }}
|
|
|
|
the output will be the string ``"01:23"`` (The ``"TIME_FORMAT"`` format
|
|
specifier for the ``de`` locale as shipped with Django is ``"H:i"``).
|
|
|
|
The ``time`` filter will only accept parameters in the format string that
|
|
relate to the time of day, not the date. If you need to format a ``date``
|
|
value, use the :tfilter:`date` filter instead (or along with :tfilter:`time` if
|
|
you need to render a full :py:class:`~datetime.datetime` value).
|
|
|
|
There is one exception the above rule: When passed a ``datetime`` value with
|
|
attached timezone information (a :ref:`time-zone-aware
|
|
<naive_vs_aware_datetimes>` ``datetime`` instance) the ``time`` filter will
|
|
accept the timezone-related :ref:`format specifiers
|
|
<date-and-time-formatting-specifiers>` ``'e'``, ``'O'`` , ``'T'`` and ``'Z'``.
|
|
|
|
When used without a format string, the ``TIME_FORMAT`` format specifier is
|
|
used::
|
|
|
|
{{ value|time }}
|
|
|
|
is the same as::
|
|
|
|
{{ value|time:"TIME_FORMAT" }}
|
|
|
|
.. templatefilter:: timesince
|
|
|
|
``timesince``
|
|
-------------
|
|
|
|
Formats a date as the time since that date (e.g., "4 days, 6 hours").
|
|
|
|
Takes an optional argument that is a variable containing the date to use as
|
|
the comparison point (without the argument, the comparison point is *now*).
|
|
For example, if ``blog_date`` is a date instance representing midnight on 1
|
|
June 2006, and ``comment_date`` is a date instance for 08:00 on 1 June 2006,
|
|
then the following would return "8 hours"::
|
|
|
|
{{ blog_date|timesince:comment_date }}
|
|
|
|
Comparing offset-naive and offset-aware datetimes will return an empty string.
|
|
|
|
Minutes is the smallest unit used, and "0 minutes" will be returned for any
|
|
date that is in the future relative to the comparison point.
|
|
|
|
.. templatefilter:: timeuntil
|
|
|
|
``timeuntil``
|
|
-------------
|
|
|
|
Similar to ``timesince``, except that it measures the time from now until the
|
|
given date or datetime. For example, if today is 1 June 2006 and
|
|
``conference_date`` is a date instance holding 29 June 2006, then
|
|
``{{ conference_date|timeuntil }}`` will return "4 weeks".
|
|
|
|
Takes an optional argument that is a variable containing the date to use as
|
|
the comparison point (instead of *now*). If ``from_date`` contains 22 June
|
|
2006, then the following will return "1 week"::
|
|
|
|
{{ conference_date|timeuntil:from_date }}
|
|
|
|
Comparing offset-naive and offset-aware datetimes will return an empty string.
|
|
|
|
Minutes is the smallest unit used, and "0 minutes" will be returned for any
|
|
date that is in the past relative to the comparison point.
|
|
|
|
.. templatefilter:: title
|
|
|
|
``title``
|
|
---------
|
|
|
|
Converts a string into titlecase by making words start with an uppercase
|
|
character and the remaining characters lowercase. This tag makes no effort to
|
|
keep "trivial words" in lowercase.
|
|
|
|
For example::
|
|
|
|
{{ value|title }}
|
|
|
|
If ``value`` is ``"my FIRST post"``, the output will be ``"My First Post"``.
|
|
|
|
.. templatefilter:: truncatechars
|
|
|
|
``truncatechars``
|
|
-----------------
|
|
|
|
Truncates a string if it is longer than the specified number of characters.
|
|
Truncated strings will end with a translatable ellipsis character ("…").
|
|
|
|
**Argument:** Number of characters to truncate to
|
|
|
|
For example::
|
|
|
|
{{ value|truncatechars:7 }}
|
|
|
|
If ``value`` is ``"Joel is a slug"``, the output will be ``"Joel i…"``.
|
|
|
|
.. templatefilter:: truncatechars_html
|
|
|
|
``truncatechars_html``
|
|
----------------------
|
|
|
|
Similar to :tfilter:`truncatechars`, except that it is aware of HTML tags. Any
|
|
tags that are opened in the string and not closed before the truncation point
|
|
are closed immediately after the truncation.
|
|
|
|
For example::
|
|
|
|
{{ value|truncatechars_html:7 }}
|
|
|
|
If ``value`` is ``"<p>Joel is a slug</p>"``, the output will be
|
|
``"<p>Joel i…</p>"``.
|
|
|
|
Newlines in the HTML content will be preserved.
|
|
|
|
.. templatefilter:: truncatewords
|
|
|
|
``truncatewords``
|
|
-----------------
|
|
|
|
Truncates a string after a certain number of words.
|
|
|
|
**Argument:** Number of words to truncate after
|
|
|
|
For example::
|
|
|
|
{{ value|truncatewords:2 }}
|
|
|
|
If ``value`` is ``"Joel is a slug"``, the output will be ``"Joel is …"``.
|
|
|
|
Newlines within the string will be removed.
|
|
|
|
.. templatefilter:: truncatewords_html
|
|
|
|
``truncatewords_html``
|
|
----------------------
|
|
|
|
Similar to :tfilter:`truncatewords`, except that it is aware of HTML tags. Any
|
|
tags that are opened in the string and not closed before the truncation point,
|
|
are closed immediately after the truncation.
|
|
|
|
This is less efficient than :tfilter:`truncatewords`, so should only be used
|
|
when it is being passed HTML text.
|
|
|
|
For example::
|
|
|
|
{{ value|truncatewords_html:2 }}
|
|
|
|
If ``value`` is ``"<p>Joel is a slug</p>"``, the output will be
|
|
``"<p>Joel is …</p>"``.
|
|
|
|
Newlines in the HTML content will be preserved.
|
|
|
|
.. templatefilter:: unordered_list
|
|
|
|
``unordered_list``
|
|
------------------
|
|
|
|
Recursively takes a self-nested list and returns an HTML unordered list --
|
|
WITHOUT opening and closing <ul> tags.
|
|
|
|
The list is assumed to be in the proper format. For example, if ``var``
|
|
contains ``['States', ['Kansas', ['Lawrence', 'Topeka'], 'Illinois']]``, then
|
|
``{{ var|unordered_list }}`` would return::
|
|
|
|
<li>States
|
|
<ul>
|
|
<li>Kansas
|
|
<ul>
|
|
<li>Lawrence</li>
|
|
<li>Topeka</li>
|
|
</ul>
|
|
</li>
|
|
<li>Illinois</li>
|
|
</ul>
|
|
</li>
|
|
|
|
.. templatefilter:: upper
|
|
|
|
``upper``
|
|
---------
|
|
|
|
Converts a string into all uppercase.
|
|
|
|
For example::
|
|
|
|
{{ value|upper }}
|
|
|
|
If ``value`` is ``"Joel is a slug"``, the output will be ``"JOEL IS A SLUG"``.
|
|
|
|
.. templatefilter:: urlencode
|
|
|
|
``urlencode``
|
|
-------------
|
|
|
|
Escapes a value for use in a URL.
|
|
|
|
For example::
|
|
|
|
{{ value|urlencode }}
|
|
|
|
If ``value`` is ``"https://www.example.org/foo?a=b&c=d"``, the output will be
|
|
``"https%3A//www.example.org/foo%3Fa%3Db%26c%3Dd"``.
|
|
|
|
An optional argument containing the characters which should not be escaped can
|
|
be provided.
|
|
|
|
If not provided, the '/' character is assumed safe. An empty string can be
|
|
provided when *all* characters should be escaped. For example::
|
|
|
|
{{ value|urlencode:"" }}
|
|
|
|
If ``value`` is ``"https://www.example.org/"``, the output will be
|
|
``"https%3A%2F%2Fwww.example.org%2F"``.
|
|
|
|
.. templatefilter:: urlize
|
|
|
|
``urlize``
|
|
----------
|
|
|
|
Converts URLs and email addresses in text into clickable links.
|
|
|
|
This template tag works on links prefixed with ``http://``, ``https://``, or
|
|
``www.``. For example, ``https://goo.gl/aia1t`` will get converted but
|
|
``goo.gl/aia1t`` won't.
|
|
|
|
It also supports domain-only links ending in one of the original top level
|
|
domains (``.com``, ``.edu``, ``.gov``, ``.int``, ``.mil``, ``.net``, and
|
|
``.org``). For example, ``djangoproject.com`` gets converted.
|
|
|
|
Links can have trailing punctuation (periods, commas, close-parens) and leading
|
|
punctuation (opening parens), and ``urlize`` will still do the right thing.
|
|
|
|
Links generated by ``urlize`` have a ``rel="nofollow"`` attribute added
|
|
to them.
|
|
|
|
For example::
|
|
|
|
{{ value|urlize }}
|
|
|
|
If ``value`` is ``"Check out www.djangoproject.com"``, the output will be
|
|
``"Check out <a href="http://www.djangoproject.com"
|
|
rel="nofollow">www.djangoproject.com</a>"``.
|
|
|
|
In addition to web links, ``urlize`` also converts email addresses into
|
|
``mailto:`` links. If ``value`` is
|
|
``"Send questions to foo@example.com"``, the output will be
|
|
``"Send questions to <a href="mailto:foo@example.com">foo@example.com</a>"``.
|
|
|
|
The ``urlize`` filter also takes an optional parameter ``autoescape``. If
|
|
``autoescape`` is ``True``, the link text and URLs will be escaped using
|
|
Django's built-in :tfilter:`escape` filter. The default value for
|
|
``autoescape`` is ``True``.
|
|
|
|
.. note::
|
|
|
|
If ``urlize`` is applied to text that already contains HTML markup, or to
|
|
email addresses that contain single quotes (``'``), things won't work as
|
|
expected. Apply this filter only to plain text.
|
|
|
|
.. templatefilter:: urlizetrunc
|
|
|
|
``urlizetrunc``
|
|
---------------
|
|
|
|
Converts URLs and email addresses into clickable links just like urlize_, but
|
|
truncates URLs longer than the given character limit.
|
|
|
|
**Argument:** Number of characters that link text should be truncated to,
|
|
including the ellipsis that's added if truncation is necessary.
|
|
|
|
For example::
|
|
|
|
{{ value|urlizetrunc:15 }}
|
|
|
|
If ``value`` is ``"Check out www.djangoproject.com"``, the output would be
|
|
``'Check out <a href="http://www.djangoproject.com"
|
|
rel="nofollow">www.djangoproj…</a>'``.
|
|
|
|
As with urlize_, this filter should only be applied to plain text.
|
|
|
|
.. templatefilter:: wordcount
|
|
|
|
``wordcount``
|
|
-------------
|
|
|
|
Returns the number of words.
|
|
|
|
For example::
|
|
|
|
{{ value|wordcount }}
|
|
|
|
If ``value`` is ``"Joel is a slug"``, the output will be ``4``.
|
|
|
|
.. templatefilter:: wordwrap
|
|
|
|
``wordwrap``
|
|
------------
|
|
|
|
Wraps words at specified line length.
|
|
|
|
**Argument:** number of characters at which to wrap the text
|
|
|
|
For example::
|
|
|
|
{{ value|wordwrap:5 }}
|
|
|
|
If ``value`` is ``Joel is a slug``, the output would be::
|
|
|
|
Joel
|
|
is a
|
|
slug
|
|
|
|
.. templatefilter:: yesno
|
|
|
|
``yesno``
|
|
---------
|
|
|
|
Maps values for ``True``, ``False``, and (optionally) ``None``, to the strings
|
|
"yes", "no", "maybe", or a custom mapping passed as a comma-separated list, and
|
|
returns one of those strings according to the value:
|
|
|
|
For example::
|
|
|
|
{{ value|yesno:"yeah,no,maybe" }}
|
|
|
|
========== ====================== ===========================================
|
|
Value Argument Outputs
|
|
========== ====================== ===========================================
|
|
``True`` ``yes``
|
|
``True`` ``"yeah,no,maybe"`` ``yeah``
|
|
``False`` ``"yeah,no,maybe"`` ``no``
|
|
``None`` ``"yeah,no,maybe"`` ``maybe``
|
|
``None`` ``"yeah,no"`` ``no`` (converts ``None`` to ``False``
|
|
if no mapping for ``None`` is given)
|
|
========== ====================== ===========================================
|
|
|
|
Internationalization tags and filters
|
|
=====================================
|
|
|
|
Django provides template tags and filters to control each aspect of
|
|
:doc:`internationalization </topics/i18n/index>` in templates. They allow for
|
|
granular control of translations, formatting, and time zone conversions.
|
|
|
|
``i18n``
|
|
--------
|
|
|
|
This library allows specifying translatable text in templates.
|
|
To enable it, set :setting:`USE_I18N` to ``True``, then load it with
|
|
``{% load i18n %}``.
|
|
|
|
See :ref:`specifying-translation-strings-in-template-code`.
|
|
|
|
``l10n``
|
|
--------
|
|
|
|
This library provides control over the localization of values in templates.
|
|
You only need to load the library using ``{% load l10n %}``, but you'll often
|
|
set :setting:`USE_L10N` to ``True`` so that localization is active by default.
|
|
|
|
See :ref:`topic-l10n-templates`.
|
|
|
|
``tz``
|
|
------
|
|
|
|
This library provides control over time zone conversions in templates.
|
|
Like ``l10n``, you only need to load the library using ``{% load tz %}``,
|
|
but you'll usually also set :setting:`USE_TZ` to ``True`` so that conversion
|
|
to local time happens by default.
|
|
|
|
See :ref:`time-zones-in-templates`.
|
|
|
|
Other tags and filters libraries
|
|
================================
|
|
|
|
Django comes with a couple of other template-tag libraries that you have to
|
|
enable explicitly in your :setting:`INSTALLED_APPS` setting and enable in your
|
|
template with the :ttag:`{% load %}<load>` tag.
|
|
|
|
``django.contrib.humanize``
|
|
---------------------------
|
|
|
|
A set of Django template filters useful for adding a "human touch" to data. See
|
|
:doc:`/ref/contrib/humanize`.
|
|
|
|
``static``
|
|
----------
|
|
|
|
.. templatetag:: static
|
|
|
|
``static``
|
|
~~~~~~~~~~
|
|
|
|
To link to static files that are saved in :setting:`STATIC_ROOT` Django ships
|
|
with a :ttag:`static` template tag. If the :mod:`django.contrib.staticfiles`
|
|
app is installed, the tag will serve files using ``url()`` method of the
|
|
storage specified by :setting:`STATICFILES_STORAGE`. For example::
|
|
|
|
{% load static %}
|
|
<img src="{% static 'images/hi.jpg' %}" alt="Hi!">
|
|
|
|
It is also able to consume standard context variables, e.g. assuming a
|
|
``user_stylesheet`` variable is passed to the template::
|
|
|
|
{% load static %}
|
|
<link rel="stylesheet" href="{% static user_stylesheet %}" type="text/css" media="screen">
|
|
|
|
If you'd like to retrieve a static URL without displaying it, you can use a
|
|
slightly different call::
|
|
|
|
{% load static %}
|
|
{% static "images/hi.jpg" as myphoto %}
|
|
<img src="{{ myphoto }}">
|
|
|
|
.. admonition:: Using Jinja2 templates?
|
|
|
|
See :class:`~django.template.backends.jinja2.Jinja2` for information on
|
|
using the ``static`` tag with Jinja2.
|
|
|
|
.. templatetag:: get_static_prefix
|
|
|
|
``get_static_prefix``
|
|
~~~~~~~~~~~~~~~~~~~~~
|
|
|
|
You should prefer the :ttag:`static` template tag, but if you need more control
|
|
over exactly where and how :setting:`STATIC_URL` is injected into the template,
|
|
you can use the :ttag:`get_static_prefix` template tag::
|
|
|
|
{% load static %}
|
|
<img src="{% get_static_prefix %}images/hi.jpg" alt="Hi!">
|
|
|
|
There's also a second form you can use to avoid extra processing if you need
|
|
the value multiple times::
|
|
|
|
{% load static %}
|
|
{% get_static_prefix as STATIC_PREFIX %}
|
|
|
|
<img src="{{ STATIC_PREFIX }}images/hi.jpg" alt="Hi!">
|
|
<img src="{{ STATIC_PREFIX }}images/hi2.jpg" alt="Hello!">
|
|
|
|
.. templatetag:: get_media_prefix
|
|
|
|
``get_media_prefix``
|
|
~~~~~~~~~~~~~~~~~~~~
|
|
|
|
Similar to the :ttag:`get_static_prefix`, ``get_media_prefix`` populates a
|
|
template variable with the media prefix :setting:`MEDIA_URL`, e.g.::
|
|
|
|
{% load static %}
|
|
<body data-media-url="{% get_media_prefix %}">
|
|
|
|
By storing the value in a data attribute, we ensure it's escaped appropriately
|
|
if we want to use it in a JavaScript context.
|