Changes to ImageFileDescriptor and ImageField to fix a few cases of setting image dimension fields.

* Moved dimension field update logic out of `ImageFileDescriptor.__set__` and into its own method on `ImageField`.
 * New `ImageField.update_dimension_fields` method is attached to model instance's `post_init` signal so that:
   * Dimension fields are set when defined before the ImageField.
   * Dimension fields are set when the field is assigned in the model constructor (fixes #11196), but only if the dimension fields don't already have values, so we avoid updating the dimensions every time an object is loaded from the database (fixes #11084).
 * Clear dimension fields when the ImageField is set to None, which also causes dimension fields to be cleared when `ImageFieldFile.delete()` is used.
 * Added many more tests for ImageField that test edge cases we weren't testing before, and moved the ImageField tests out of `file_storage` and into their own module within `model_fields`.


git-svn-id: http://code.djangoproject.com/svn/django/trunk@10858 bcc190cf-cafb-0310-a4f2-bffc1f526a37

tests/regressiontests/file_storage/models.py

@@ -1,93 +0,0 @@
-import os
-import tempfile
-import shutil
-from django.db import models
-from django.core.files.storage import FileSystemStorage
-from django.core.files.base import ContentFile
-
-# Test for correct behavior of width_field/height_field.
-# Of course, we can't run this without PIL.
-
-try:
-    # Checking for the existence of Image is enough for CPython, but
-    # for PyPy, you need to check for the underlying modules
-    from PIL import Image, _imaging
-except ImportError:
-    Image = None
-
-# If we have PIL, do these tests
-if Image:
-    temp_storage_dir = tempfile.mkdtemp()
-    temp_storage = FileSystemStorage(temp_storage_dir)
-
-    class Person(models.Model):
-        name = models.CharField(max_length=50)
-        mugshot = models.ImageField(storage=temp_storage, upload_to='tests',
-                                    height_field='mug_height',
-                                    width_field='mug_width')
-        mug_height = models.PositiveSmallIntegerField()
-        mug_width = models.PositiveSmallIntegerField()
-
-    __test__ = {'API_TESTS': """
->>> from django.core.files import File
->>> image_data = open(os.path.join(os.path.dirname(__file__), "test.png"), 'rb').read()
->>> p = Person(name="Joe")
->>> p.mugshot.save("mug", ContentFile(image_data))
->>> p.mugshot.width
-16
->>> p.mugshot.height
-16
->>> p.mug_height
-16
->>> p.mug_width
-16
-
-# Bug #9786: Ensure '==' and '!=' work correctly.
->>> image_data = open(os.path.join(os.path.dirname(__file__), "test1.png"), 'rb').read()
->>> p1 = Person(name="Bob")
->>> p1.mugshot.save("mug", ContentFile(image_data))
->>> p2 = Person.objects.get(name="Joe")
->>> p.mugshot == p2.mugshot
-True
->>> p.mugshot != p2.mugshot
-False
->>> p.mugshot != p1.mugshot
-True
-
-Bug #9508: Similarly to the previous test, make sure hash() works as expected
-(equal items must hash to the same value).
->>> hash(p.mugshot) == hash(p2.mugshot)
-True
-
-# Bug #8175: correctly delete files that have been removed off the file system.
->>> import os
->>> p2 = Person(name="Fred")
->>> p2.mugshot.save("shot", ContentFile(image_data))
->>> os.remove(p2.mugshot.path)
->>> p2.delete()
-
-# Bug #8534: FileField.size should not leave the file open.
->>> p3 = Person(name="Joan")
->>> p3.mugshot.save("shot", ContentFile(image_data))
-
-# Get a "clean" model instance
->>> p3 = Person.objects.get(name="Joan")
-
-# It won't have an opened file.
->>> p3.mugshot.closed
-True
-
-# After asking for the size, the file should still be closed.
->>> _ = p3.mugshot.size
->>> p3.mugshot.closed
-True
-
-# Make sure that wrapping the file in a file still works
->>> p3.mugshot.file.open()
->>> p = Person.objects.create(name="Bob The Builder", mugshot=File(p3.mugshot.file))
->>> p.save()
->>> p3.mugshot.file.close() 
-
-# Delete all test files
->>> shutil.rmtree(temp_storage_dir)
-"""}