Commit 8f2feb2e authored by Gabriel Hurley's avatar Gabriel Hurley
Browse files

[1.2.X] Fixed #13162 and #11597 -- Improved the file handling documentation:... 

[1.2.X] Fixed #13162 and #11597 -- Improved the file handling documentation: Removed documentation of methods on django.core.files.File that did not exist, added documentation for undocumented methods and attributes that did exist, did a general cleanup of the text and organization, and added more metadata targets. Thanks to amenasse and tyrion.mx for the reports.

Backport of [14833] from trunk.

git-svn-id: http://code.djangoproject.com/svn/django/branches/releases/1.2.X@14834 bcc190cf-cafb-0310-a4f2-bffc1f526a37
parent a4d88f00

docs/ref/files/file.txt

+73 −59
Original line number Diff line number Diff line 
The ``File`` object

===================



.. currentmodule:: django.core.files

The :mod:`django.core.files` module and its submodules contain built-in classes

for basic file handling in Django.



``File`` attributes and methods

-------------------------------

.. currentmodule:: django.core.files



The :mod:`django.core.files` module contains a built-in class for basic file

handling in Django. The :class:`File` class has the following attributes and

methods:

The ``File`` Class

------------------



.. class:: File(file_object)



    .. attribute:: name



        The name of file including the relative path from :setting:`MEDIA_ROOT`.

    The :class:`File` is a thin wrapper around Python's built-in file object

    with some Django-specific additions. Internally, Django uses this class

    any time it needs to represent a file.

    

    .. attribute:: path

    :class:`File` objects have the following attributes and methods:



        The absolute path to the file's location on a local filesystem.

    .. attribute:: name



        :doc:`Custom file storage systems </howto/custom-file-storage>` may not store

        files locally; files stored on these systems will have a ``path`` of

        ``None``.

        The name of file including the relative path from

        :setting:`MEDIA_ROOT`.



    .. attribute:: url

    .. attribute:: size



        The URL where the file can be retrieved. This is often useful in

        :doc:`templates </topics/templates>`; for example, a bit of a template for

        displaying a ``Car`` (see above) might look like:

        The size of the file in bytes.



        .. code-block:: html+django

    .. attribute:: file



            <img src='{{ car.photo.url }}' alt='{{ car.name }}' />

        The underlying Python ``file`` object passed to

        :class:`~django.core.files.File`.



    .. attribute:: size

    .. attribute:: mode



        The size of the file in bytes.

        The read/write mode for the file.



    .. method:: open([mode=None])



        Open or reopen the file (which by definition also does ``File.seek(0)``).

        The ``mode`` argument allows the same values as Python's standard

        ``open()``.

        Open or reopen the file (which by definition also does

        ``File.seek(0)``). The ``mode`` argument allows the same values

        as Python's standard ``open()``.



        When reopening a file, ``mode`` will override whatever mode the file was

        originally opened with; ``None`` means to reopen with the original mode.

        When reopening a file, ``mode`` will override whatever mode the file

        was originally opened with; ``None`` means to reopen with the original

        mode.



    .. method:: read([num_bytes=None])



        Read content from the file. The optional ``size`` is the number of bytes to

        read; if not specified, the file will be read to the end.

        Read content from the file. The optional ``size`` is the number of

        bytes to read; if not specified, the file will be read to the end.



    .. method:: __iter__()
@@ -61,38 +59,65 @@ methods: 
        Iterate over the file yielding "chunks" of a given size. ``chunk_size``

        defaults to 64 KB.



        This is especially useful with very large files since it allows them to be

        streamed off disk and avoids storing the whole file in memory.

        This is especially useful with very large files since it allows them to

        be streamed off disk and avoids storing the whole file in memory.



    .. method:: multiple_chunks([chunk_size=None])



        Returns ``True`` if the file is large enough to require multiple chunks to

        access all of its content give some ``chunk_size``.

        Returns ``True`` if the file is large enough to require multiple chunks

        to access all of its content give some ``chunk_size``.



    .. method:: write([content])



        Writes the specified content string to the file. Depending on the storage

        system behind the scenes, this content might not be fully committed until

        ``close()`` is called on the file.

        Writes the specified content string to the file. Depending on the

        storage system behind the scenes, this content might not be fully

        committed until ``close()`` is called on the file.



    .. method:: close()



        Close the file.



    In addition to the listed methods, :class:`~django.core.files.File` exposes

    the following attributes and methods of the underlying ``file`` object:

    ``encoding``, ``fileno``, ``flush``, ``isatty``, ``newlines``,

    ``read``, ``readinto``, ``readlines``, ``seek``, ``softspace``, ``tell``,

    ``truncate``, ``writelines``, ``xreadlines``.



.. currentmodule:: django.core.files.base



The ``ContentFile`` Class

-------------------------



.. class:: ContentFile(File)



    The ``ContentFile`` class inherits from :class:`~django.core.files.File`,

    but unlike :class:`~django.core.files.File` it operates on string content,

    rather than an actual file. For example::



        from django.core.files.base import ContentFile



        f1 = ContentFile("my string content")

        f2 = ContentFile(u"my unicode content encoded as UTF-8".encode('UTF-8'))



.. currentmodule:: django.core.files.images



Additional ``ImageFile`` attributes

------------------------------------

The ``ImageFile`` Class

-----------------------



.. class:: ImageFile(file_object)



    Django provides a built-in class specifically for images.

    :class:`django.core.files.images.ImageFile` inherits all the attributes

    and methods of :class:`~django.core.files.File`, and additionally

    provides the following:



    .. attribute:: width



        Width of the image.

        Width of the image in pixels.



    .. attribute:: height



        Height of the image.

        Height of the image in pixels.



.. currentmodule:: django.core.files
@@ -100,7 +125,7 @@ Additional methods on files attached to objects 
-----------------------------------------------



Any :class:`File` that's associated with an object (as with ``Car.photo``,

above) will also have a couple of extra methods:

below) will also have a couple of extra methods:



.. method:: File.save(name, content, [save=True])
@@ -116,23 +141,12 @@ above) will also have a couple of extra methods: 


        >>> car.photo.save('myphoto.jpg', contents, save=True)



    Note that the ``content`` argument must be an instance of

    :class:`File` or of a subclass of :class:`File` such as :class:`ContentFile`.

    Note that the ``content`` argument must be an instance of either

    :class:`File` or of a subclass of :class:`File`, such as

    :class:`ContentFile`.



.. method:: File.delete([save=True])



    Remove the file from the model instance and delete the underlying file. The

    ``save`` argument works as above.



``ContentFile`` objects

-----------------------



.. class:: ContentFile(File)



A ``ContentFile`` is a File-like object that takes string content, rather

than an actual file::



    from django.core.files.base import ContentFile



    f1 = ContentFile("my string content")

    f2 = ContentFile(u"my unicode content encoded as UTF-8".encode('UTF-8'))
 
    Removes the file from the model instance and deletes the underlying file.

    If ``save`` is ``True``, the model's ``save()`` method will be called once

    the file is deleted.

docs/ref/files/index.txt

+1 −1
Original line number Diff line number Diff line
@@ -6,7 +6,7 @@ File handling 
   :synopsis: File handling and storage



.. toctree::

   :maxdepth: 1

   :maxdepth: 2



   file

   storage

docs/topics/files.txt

+5 −5
Original line number Diff line number Diff line
@@ -50,9 +50,9 @@ it has all the methods and attributes described below. 
The ``File`` object

===================



Internally, Django uses a ``django.core.files.File`` any time it needs to

represent a file. This object is a thin wrapper around Python's `built-in file

object`_ with some Django-specific additions.

Internally, Django uses a :class:`django.core.files.File` instance any time it

needs to represent a file. This object is a thin wrapper around Python's

`built-in file object`_ with some Django-specific additions.



.. _built-in file object: http://docs.python.org/library/stdtypes.html#bltin-file-objects
@@ -68,8 +68,8 @@ using a Python built-in ``file`` object:: 
    >>> f = open('/tmp/hello.world', 'w')

    >>> myfile = File(f)



Now you can use any of the ``File`` attributes and methods documented in

:doc:`/ref/files/file`.

Now you can use any of the documented attributes and methods

of the :class:`~django.core.files.File` class.



File storage

============