Merged to [3519]

git-svn-id: http://code.djangoproject.com/svn/django/branches/generic-auth@4024 bcc190cf-cafb-0310-a4f2-bffc1f526a37

1 files changed, 101 insertions, 0 deletions

diff --git a/django/core/serializers/python.py b/django/core/serializers/python.py
new file mode 100644
index 0000000000..4181bc7f2b
--- /dev/null
+++ b/django/core/serializers/python.py
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+"""
+A Python "serializer". Doesn't do much serializing per se -- just converts to
+and from basic Python data types (lists, dicts, strings, etc.). Useful as a basis for
+other serializers.
+"""
+
+from django.conf import settings
+from django.core.serializers import base
+from django.db import models
+
+class Serializer(base.Serializer):
+    """
+    Serializes a QuerySet to basic Python objects.
+    """
+    
+    def start_serialization(self):
+        self._current = None
+        self.objects = []
+        
+    def end_serialization(self):
+        pass
+        
+    def start_object(self, obj):
+        self._current = {}
+        
+    def end_object(self, obj):
+        self.objects.append({
+            "model"  : str(obj._meta),
+            "pk"     : str(obj._get_pk_val()),
+            "fields" : self._current
+        })
+        self._current = None
+        
+    def handle_field(self, obj, field):
+        self._current[field.name] = getattr(obj, field.name)
+        
+    def handle_fk_field(self, obj, field):
+        related = getattr(obj, field.name)
+        if related is not None:
+            related = related._get_pk_val()
+        self._current[field.name] = related
+    
+    def handle_m2m_field(self, obj, field):
+        self._current[field.name] = [related._get_pk_val() for related in getattr(obj, field.name).iterator()]
+    
+    def getvalue(self):
+        return self.objects
+
+def Deserializer(object_list, **options):
+    """
+    Deserialize simple Python objects back into Django ORM instances.
+    
+    It's expected that you pass the Python objects themselves (instead of a
+    stream or a string) to the constructor
+    """
+    models.get_apps()
+    for d in object_list:
+        # Look up the model and starting build a dict of data for it.
+        Model = _get_model(d["model"])
+        data = {Model._meta.pk.name : d["pk"]}
+        m2m_data = {}
+        
+        # Handle each field
+        for (field_name, field_value) in d["fields"].iteritems():
+            if isinstance(field_value, unicode):
+                field_value = field_value.encode(options.get("encoding", settings.DEFAULT_CHARSET))
+                
+            field = Model._meta.get_field(field_name)
+            
+            # Handle M2M relations (with in_bulk() for performance)
+            if field.rel and isinstance(field.rel, models.ManyToManyRel):
+                pks = []
+                for pk in field_value:
+                    if isinstance(pk, unicode):
+                        pk = pk.encode(options.get("encoding", settings.DEFAULT_CHARSET))
+                m2m_data[field.name] = field.rel.to._default_manager.in_bulk(field_value).values()
+                
+            # Handle FK fields
+            elif field.rel and isinstance(field.rel, models.ManyToOneRel):
+                try:
+                    data[field.name] = field.rel.to._default_manager.get(pk=field_value)
+                except field.rel.to.DoesNotExist:
+                    data[field.name] = None
+                    
+            # Handle all other fields
+            else:
+                data[field.name] = field.to_python(field_value)
+                
+        yield base.DeserializedObject(Model(**data), m2m_data)
+
+def _get_model(model_identifier):
+    """
+    Helper to look up a model from an "app_label.module_name" string.
+    """
+    try:
+        Model = models.get_model(*model_identifier.split("."))
+    except TypeError:
+        Model = None
+    if Model is None:
+        raise base.DeserializationError("Invalid model identifier: '%s'" % model_identifier)
+    return Model