Yes yes yes -- more documentation improvements
git-svn-id: http://code.djangoproject.com/svn/django/trunk@67 bcc190cf-cafb-0310-a4f2-bffc1f526a37
This commit is contained in:
parent
05c5dabb8f
commit
604cd7fe14
|
@ -305,4 +305,44 @@ objects fields, then call the object's ``save()`` method::
|
|||
Creating new objects
|
||||
====================
|
||||
|
||||
...
|
||||
Creating new objects (i.e. ``INSERT``) is done by creating new instances
|
||||
of objects then calling save() on them::
|
||||
|
||||
>>> p = polls.Poll(id=None,
|
||||
... slug="eggs",
|
||||
... question="How do you like your eggs?",
|
||||
... pub_date=datetime.datetime.now(),
|
||||
... expire_date=some_future_date)
|
||||
>>> p.save()
|
||||
|
||||
Calling ``save()`` on an object with an id if ``None`` signifies to
|
||||
Django that the object is new and should be inserted.
|
||||
|
||||
Related objects (i.e. ``Choices``) are created using convience functions::
|
||||
|
||||
>>> p.add_choice(choice="Over easy", votes=0)
|
||||
>>> p.add_choice(choice="Scrambled", votes=0)
|
||||
>>> p.add_choice(choice="Fertilized", votes=0)
|
||||
>>> p.add_choice(choice="Poached", votes=0)
|
||||
>>> p.get_choice_count()
|
||||
4
|
||||
|
||||
Each of those ``add_choice`` methods is equivilent to (except obviously much
|
||||
simpler than)::
|
||||
|
||||
>>> c = polls.Choice(id=None,
|
||||
... poll_id=p.id,
|
||||
... choice="Over easy",
|
||||
... votes=0)
|
||||
>>> c.save()
|
||||
|
||||
Note that when using the `add_foo()`` methods, you do not give any value
|
||||
for the ``id`` field, nor do you give a value for the field that stores
|
||||
the relation (``poll_id`` in this case).
|
||||
|
||||
Deleting objects
|
||||
================
|
||||
|
||||
Just cause we're crazy like that, the delete method is named ``delete()``.
|
||||
Yeah, you never know what we're going to do next.
|
||||
|
||||
|
|
40
docs/faq.txt
40
docs/faq.txt
|
@ -66,12 +66,12 @@ Lawrence, Kansas, USA.
|
|||
`chicagocrime.org`_.
|
||||
|
||||
`Simon Willison`_
|
||||
Simon is a well-respected Web developer from England. He had a one-year stint
|
||||
at World Online, during which time he and Adrian developed Django from scratch.
|
||||
He's enthusiastic, he's passionate about best practices in Web development, and
|
||||
he really likes squirrels. Probably to a fault. He went back to England to
|
||||
finish his degree and is poised to continue doing big, exciting things on the Web.
|
||||
Read his weblog at `simon.incutio.com`_.
|
||||
Simon is a well-respected Web developer from England. He had a one-year
|
||||
stint at World Online, during which time he and Adrian developed Django from
|
||||
scratch. He's enthusiastic, he's passionate about best practices in Web
|
||||
development, and he really likes squirrels. Probably to a fault. He went
|
||||
back to England to finish his degree and is poised to continue doing big,
|
||||
exciting things on the Web. Read his weblog at `simon.incutio.com`_.
|
||||
|
||||
`Jacob Kaplan-Moss`_
|
||||
Jacob is a whipper-snapper from California who spends equal time coding and
|
||||
|
@ -102,17 +102,35 @@ How do I get started?
|
|||
|
||||
We're working on this documentation as you read this.
|
||||
|
||||
What are Django's prerequisites?
|
||||
--------------------------------
|
||||
|
||||
Django requires Python_ 2.3 or later, Apache2_, and mod_python_. You'll
|
||||
also need a database engine; PostgreSQL_ is recommended, and MySQL_ is
|
||||
supported.
|
||||
|
||||
We're currently working on expanding those options: WSGI_ support is in the
|
||||
works (which will allow Django to run under CGI, FCGI, etc.), as is support for
|
||||
a number of other database backends.
|
||||
|
||||
.. _Python: http://www.python.org/
|
||||
.. _Apache2: http://httpd.apache.org/
|
||||
.. _mod_python: http://www.modpython.org/
|
||||
.. _PostgreSQL: http://www.postgresql.org/
|
||||
.. _MySQL: http://www.mysql.com/
|
||||
.. _WSGI: http://www.python.org/peps/pep-0333.html
|
||||
|
||||
The admin interface
|
||||
===================
|
||||
|
||||
The dynamically-generated admin site is ugly! How can I change it?
|
||||
------------------------------------------------------------------
|
||||
|
||||
We think it's very purty, but if you don't agree, you can modify the admin site's
|
||||
presentation by editing the CSS stylesheet and/or associated image files. The
|
||||
site is built using semantic HTML, so any changes you'd like to make should be
|
||||
possible by editing the CSS stylesheet. We've got a `guide to the CSS used
|
||||
in the admin`_ to get you started.
|
||||
We think it's very purty, but if you don't agree, you can modify the admin
|
||||
site's presentation by editing the CSS stylesheet and/or associated image files.
|
||||
The site is built using semantic HTML, so any changes you'd like to make should
|
||||
be possible by editing the CSS stylesheet. We've got a `guide to the CSS used in
|
||||
the admin`_ to get you started.
|
||||
|
||||
.. _`guide to the CSS used in the admin`: http://www.djangoproject.com/documentation/admin_css/
|
||||
|
||||
|
|
|
@ -181,8 +181,6 @@ options that are common to all field types. These options are:
|
|||
``null`` If ``True`` empty values in the field will be
|
||||
stored as ``NULL`` in the database.
|
||||
|
||||
XXX does null imply blank? XXX
|
||||
|
||||
``primary_key`` If ``True`` this field is the primary key for the
|
||||
table. You only need to use this if you don't want
|
||||
the standard "id" field created and used as the
|
||||
|
@ -302,8 +300,8 @@ Field Types
|
|||
|
||||
meta.ForeignKey(Pizza)
|
||||
|
||||
``ForeignKey`` fields take a large number of options for defining how the
|
||||
relationship should work:
|
||||
``ForeignKey`` fields take a large number of extra options for defining how
|
||||
the relationship should work:
|
||||
|
||||
======================= ============================================================
|
||||
Option Description
|
||||
|
@ -364,7 +362,7 @@ Field Types
|
|||
|
||||
Not used with ``edit_inline``.
|
||||
|
||||
``rel_name`` The name of the relation. In the above exmaple,
|
||||
``rel_name`` The name of the relation. In the above example,
|
||||
this would default to 'pizza' (so that the
|
||||
``Toppings`` object would have a ``get_pizza()``
|
||||
function; if you set ``rel_name`` to "pie", then
|
||||
|
@ -431,12 +429,60 @@ Field Types
|
|||
An IP address, in string format (i.e. "24.124.1.30").
|
||||
|
||||
``ManyToManyField``
|
||||
XXX document once Adrian reworks this XXX
|
||||
A many-to-many relation to another object. For example (taken from the
|
||||
``core.flatfiles`` object::
|
||||
|
||||
class FlatFile(meta.Model):
|
||||
fields = (
|
||||
...
|
||||
meta.ManyToManyField(Site),
|
||||
)
|
||||
|
||||
Many-to-many relations are a bit different from other fields. First, they
|
||||
aren't actually a field per se since they use a intermediary join table.
|
||||
Second, they don't take any of the same options as the rest of the fields,
|
||||
the only options taken are:
|
||||
|
||||
======================= ============================================================
|
||||
Option Description
|
||||
======================= ============================================================
|
||||
``related_name`` See the description of ``related_name`` in
|
||||
``ManyToOneField``, above.
|
||||
|
||||
``filter_interface`` Use a nifty unobtrusive Javascript "filter" interface
|
||||
instead of the usability-challenged ``<select multiple>``.
|
||||
The value should be ``meta.HORIZONTAL`` or ``meta.VERTICAL``
|
||||
(i.e. should the interface be stacked horizontally or
|
||||
vertically).
|
||||
|
||||
``limit_choices_to`` See the description under ``ManyToOneField``, above.
|
||||
======================= ============================================================
|
||||
|
||||
``NullBooleanField``
|
||||
Like a ``BooleanField``, but allows ``NULL`` as one of the options. Use this
|
||||
instead of a ``BooleanField`` with ``null=True`` .
|
||||
|
||||
``OneToOneField``
|
||||
Signifies a one-to-one relationship. This is most useful on the primary key
|
||||
of an object when that object "extends" another object in some way.
|
||||
|
||||
For example, if you are building a database of "places", you would build pretty
|
||||
standard stuff like address, phone number, etc. in the database. If you then
|
||||
wanted to build a database of restaurants on top of the places, instead of
|
||||
repeating yourself and replicating those fields in the restaurants object, you
|
||||
could make ``Restaurant`` have a ``OneToOneField`` to ``Place`` (since
|
||||
a restaurant "is-a" place). This ``OneToOneField`` will actually replace
|
||||
the primary key ``id`` field (since one-to-one relations share the same
|
||||
primary key), and has a few in the admin interface:
|
||||
|
||||
* No selection interface is displayed on ``Restaurant`` pages; there will
|
||||
be one (and only one) ``Restaurant`` for each place.
|
||||
|
||||
* On the ``Restaurant`` change list, every single ``Place`` -- weather it
|
||||
has an associated ``Restaurant`` or not -- will be displayed. Adding
|
||||
a ``Restaurant`` to a ``Place`` just means filling out the required
|
||||
``Restaurant`` fields.
|
||||
|
||||
``PhoneNumberField``
|
||||
Validates that the value is a valid phone number.
|
||||
|
||||
|
@ -574,20 +620,112 @@ object, which has the following options (of which only ``fields`` is required):
|
|||
|
||||
``ordering``
|
||||
An ordering tuple (see the `Options for models`_, above) that gives a
|
||||
different ordering for the admin change list. If not given, the
|
||||
model's default ordering will be used.
|
||||
different ordering for the admin change list. If not given, the model's
|
||||
default ordering will be used.
|
||||
|
||||
``save_as``
|
||||
Enables a "save as" feature on object pages. Normally, objects have
|
||||
three save options: "Save", "Save and continue editing", and "Save
|
||||
and add another". If ``save_as`` is ``True``, "Save and add another"
|
||||
will be replaced by a "Save as" button.
|
||||
Enables a "save as" feature on object pages. Normally, objects have three
|
||||
save options: "Save", "Save and continue editing", and "Save and add
|
||||
another". If ``save_as`` is ``True``, "Save and add another" will be
|
||||
replaced by a "Save as" button.
|
||||
|
||||
``save_on_top``
|
||||
If this option is ``True``, object pages will have the save buttons
|
||||
across the top as well as at the bottom of the page.
|
||||
If this option is ``True``, object pages will have the save buttons across
|
||||
the top as well as at the bottom of the page.
|
||||
|
||||
``search_fields``
|
||||
A list of fields to provide a text search for. These fields should,
|
||||
obviously, be some kind of text field.
|
||||
|
||||
Model methods
|
||||
=============
|
||||
|
||||
There are a number of methods you can define on model objects to control the
|
||||
object's behavior. First, any methods you define will be available as methods
|
||||
of object instances. For example::
|
||||
|
||||
class Pizza(meta.Model):
|
||||
fields = (
|
||||
...
|
||||
)
|
||||
|
||||
def is_disgusting(self):
|
||||
return "anchovices" in [topping.name for topping in self.get_topping_list()]
|
||||
|
||||
Now, every ``Pizza`` object will have a ``is_disgusting()`` method.
|
||||
|
||||
There are a few object methods that have special meaning:
|
||||
|
||||
``__repr__``
|
||||
Django uses ``repr(obj)`` in a number of places, the most notable as the
|
||||
value inserted into a template when it displays an object. Thus, you should
|
||||
return a nice, human-readable string for the object's ``__repr__``.
|
||||
|
||||
``get_absolute_url``
|
||||
If an object defines a ``get_absolute_url`` method, it is used to
|
||||
associate a URL with an object. For example:
|
||||
|
||||
def get_absolute_url(self):
|
||||
return "/pizzas/%i/" % self.id
|
||||
|
||||
The most useful place this is used is in the admin interface; if an object
|
||||
defines ``get_absolute_url`` then the object detail page will have a "View
|
||||
on site" link that will jump you directly to the object's public view.
|
||||
|
||||
``_pre_save``
|
||||
This method will be called just before the object is saved into the
|
||||
database; you can use it to (for example) calculate aggregate values from
|
||||
other fields before the object is saved.
|
||||
|
||||
``_post_save``
|
||||
Called just after the object is saved to the database. This could be used
|
||||
to update other tables, update cached information, etc.
|
||||
|
||||
Module-level methods
|
||||
--------------------
|
||||
|
||||
Since each data class in effect turns into a module, there are times you'll want
|
||||
to write methods that live in that module. Any model method that begins with
|
||||
"_module_" is turned into a module-level method::
|
||||
|
||||
class Pizza(meta.Model):
|
||||
fields = (
|
||||
...
|
||||
)
|
||||
|
||||
def _module_get_pizzas_to_deliver():
|
||||
return get_list(delivered__exact=False)
|
||||
|
||||
This will make the top-level ``pizzas`` module have a ``get_pizzas_to_deliver()``
|
||||
method::
|
||||
|
||||
>>> from django.models.pizza_hut import pizzas
|
||||
>>> pizzas.get_pizzas_to_deliver()
|
||||
[ ... ]
|
||||
|
||||
Note that the scope of these methods is modified to be the same has the module
|
||||
scope (so that's how the raw ``get_list`` works).
|
||||
|
||||
Manipulator methods
|
||||
-------------------
|
||||
|
||||
Similarly, you can add methods to the object's manipulators (see the formfields
|
||||
documentation for more on manipulators) by defining methods that being with
|
||||
"_manipulator_". This is most useful for providing custom validators for certain
|
||||
fields since manipulators automatically call any method that begins with
|
||||
"validate"::
|
||||
|
||||
class Pizza(meta.Model):
|
||||
fields = (
|
||||
...
|
||||
)
|
||||
|
||||
def _manipulator_validate_customer_id(self, field_data, all_data):
|
||||
from django.core import validators
|
||||
from django.conf.settings import BAD_CUSTOMER_IDS
|
||||
|
||||
if int(field_data) in BAD_CUSTOMER_IDS:
|
||||
raise validators.ValidationError("We don't deliver to this customer")
|
||||
|
||||
|
||||
|
Loading…
Reference in New Issue