Added initial cut at serialization framework, along with some basic tests and a stab at some docs. This is all a bit rough right now, so expect some bumps.

git-svn-id: http://code.djangoproject.com/svn/django/trunk@3225 bcc190cf-cafb-0310-a4f2-bffc1f526a37

2 files changed, 94 insertions, 0 deletions

diff --git a/tests/modeltests/serializers/__init__.py b/tests/modeltests/serializers/__init__.py
new file mode 100644
index 0000000000..e69de29bb2
--- /dev/null
+++ b/tests/modeltests/serializers/__init__.py
diff --git a/tests/modeltests/serializers/models.py b/tests/modeltests/serializers/models.py
new file mode 100644
index 0000000000..8c9483beba
--- /dev/null
+++ b/tests/modeltests/serializers/models.py
@@ -0,0 +1,94 @@
+"""
+XXX. Serialization
+
+``django.core.serializers`` provides interfaces to converting Django querysets
+to and from "flat" data (i.e. strings).
+"""
+
+from django.db import models
+
+class Category(models.Model):
+    name = models.CharField(maxlength=20)
+
+    class Meta:
+       ordering = ('name',)
+
+    def __str__(self):
+        return self.name
+
+class Author(models.Model):
+    name = models.CharField(maxlength=20)
+
+    class Meta:
+        ordering = ('name',)
+    
+    def __str__(self):
+        return self.name
+
+class Article(models.Model):
+    author = models.ForeignKey(Author)
+    headline = models.CharField(maxlength=50)
+    pub_date = models.DateTimeField()
+    categories = models.ManyToManyField(Category)
+
+    class Meta:
+       ordering = ('pub_date',)
+
+    def __str__(self):
+        return self.headline
+
+API_TESTS = """
+# Create some data:
+>>> from datetime import datetime
+>>> sports = Category(name="Sports")
+>>> music = Category(name="Music")
+>>> op_ed = Category(name="Op-Ed")
+>>> sports.save(); music.save(); op_ed.save()
+
+>>> joe = Author(name="Joe")
+>>> jane = Author(name="Jane")
+>>> joe.save(); jane.save()
+
+>>> a1 = Article(
+...     author = jane,
+...     headline = "Poker has no place on ESPN",
+...     pub_date = datetime(2006, 6, 16, 11, 00))
+>>> a2 = Article(
+...     author = joe,
+...     headline = "Time to reform copyright",
+...     pub_date = datetime(2006, 6, 16, 13, 00))
+>>> a1.save(); a2.save()
+>>> a1.categories = [sports, op_ed]
+>>> a2.categories = [music, op_ed]
+
+# Serialize a queryset to XML
+>>> from django.core import serializers
+>>> xml = serializers.serialize("xml", Article.objects.all())
+
+# The output is valid XML
+>>> from xml.dom import minidom
+>>> dom = minidom.parseString(xml)
+
+# Deserializing has a similar interface, except that special DeserializedObject
+# instances are returned.  This is because data might have changed in the 
+# database since the data was serialized (we'll simulate that below).
+>>> for obj in serializers.deserialize("xml", xml):
+...     print obj
+<DeserializedObject: Poker has no place on ESPN>
+<DeserializedObject: Time to reform copyright>
+
+# Deserializing data with different field values doesn't change anything in the
+# database until we call save():
+>>> xml = xml.replace("Poker has no place on ESPN", "Poker has no place on television")
+>>> objs = list(serializers.deserialize("xml", xml))
+
+# Even those I deserialized, the database hasn't been touched
+>>> Article.objects.all()
+[<Article: Poker has no place on ESPN>, <Article: Time to reform copyright>]
+
+# But when I save, the data changes as you might except.
+>>> objs[0].save()
+>>> Article.objects.all()
+[<Article: Poker has no place on television>, <Article: Time to reform copyright>]
+
+"""