Fixes #15732 -- better introduction of template filter decorator concepts (first register, then stringfilter). Thanks for the patch, hahasee.
git-svn-id: http://code.djangoproject.com/svn/django/trunk@16251 bcc190cf-cafb-0310-a4f2-bffc1f526a37
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@ -105,23 +105,6 @@ your function. Example::
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"Converts a string into all lowercase"
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return value.lower()
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Template filters that expect strings
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~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
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If you're writing a template filter that only expects a string as the first
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argument, you should use the decorator ``stringfilter``. This will
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convert an object to its string value before being passed to your function::
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from django.template.defaultfilters import stringfilter
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@stringfilter
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def lower(value):
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return value.lower()
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This way, you'll be able to pass, say, an integer to this filter, and it
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won't cause an ``AttributeError`` (because integers don't have ``lower()``
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methods).
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Registering custom filters
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~~~~~~~~~~~~~~~~~~~~~~~~~~
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@ -140,17 +123,36 @@ The ``Library.filter()`` method takes two arguments:
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You can use ``register.filter()`` as a decorator instead::
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@register.filter(name='cut')
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@stringfilter
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def cut(value, arg):
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return value.replace(arg, '')
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@register.filter
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def lower(value):
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return value.lower()
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If you leave off the ``name`` argument, as in the second example above, Django
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will use the function's name as the filter name.
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Template filters that expect strings
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~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
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If you're writing a template filter that only expects a string as the first
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argument, you should use the decorator ``stringfilter``. This will
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convert an object to its string value before being passed to your function::
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from django import template
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from django.template.defaultfilters import stringfilter
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register = template.Library()
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@register.filter
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@stringfilter
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def lower(value):
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return value.lower()
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If you leave off the ``name`` argument, as in the second example above, Django
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will use the function's name as the filter name.
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This way, you'll be able to pass, say, an integer to this filter, and it
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won't cause an ``AttributeError`` (because integers don't have ``lower()``
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methods).
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Filters and auto-escaping
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~~~~~~~~~~~~~~~~~~~~~~~~~
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