Add models and various shortcuts to allow for AleaIdField with primary_key=True.

dddp/admin.py

@@ -104,7 +104,7 @@ class SubscriptionCollection(admin.ModelAdmin):
 
 
 for name, attr in vars(models).items():
-    if hasattr(attr, '_meta'):
+    if hasattr(attr, '_meta') and not getattr(attr._meta, 'abstract'):
         model_admin = locals().get(name, None)
         if model_admin is not False:
             admin.site.register(attr, model_admin)

dddp/api.py

@@ -28,7 +28,9 @@ import ejson
 from dddp import (
     AlreadyRegistered, THREAD_LOCAL as this, ADDED, CHANGED, REMOVED,
 )
-from dddp.models import Connection, Subscription, get_meteor_id, get_meteor_ids
+from dddp.models import (
+    AleaIdField, Connection, Subscription, get_meteor_id, get_meteor_ids,
+)
 
 
 XMIN = {'select': {'xmin': "'xmin'"}}
@@ -600,9 +602,12 @@ class DDP(APIMixin):
                 model_name=model_name(qs.model),
                 collection_name=col.name,
             )
-            meteor_ids = get_meteor_ids(
-                qs.model, qs.values_list('pk', flat=True),
-            )
+            if isinstance(col.model._meta.pk, AleaIdField):
+                meteor_ids = None
+            else:
+                meteor_ids = get_meteor_ids(
+                    qs.model, qs.values_list('pk', flat=True),
+                )
             for obj in qs:
                 payload = col.obj_change_as_msg(obj, ADDED, meteor_ids)
                 this.send(payload)
@@ -615,9 +620,12 @@ class DDP(APIMixin):
             connection=this.ws.connection, sub_id=id_,
         )
         for col, qs in self.sub_unique_objects(sub):
-            meteor_ids = get_meteor_ids(
-                qs.model, qs.values_list('pk', flat=True),
-            )
+            if isinstance(col.model._meta.pk, AleaIdField):
+                meteor_ids = None
+            else:
+                meteor_ids = get_meteor_ids(
+                    qs.model, qs.values_list('pk', flat=True),
+                )
             for obj in qs:
                 payload = col.obj_change_as_msg(obj, REMOVED, meteor_ids)
                 this.send(payload)

dddp/models.py

@@ -23,10 +23,29 @@ def get_meteor_id(obj_or_model, obj_pk=None):
     if model is ObjectMapping:
         # this doesn't make sense - raise TypeError
         raise TypeError("Can't map ObjectMapping instances through self.")
-    if obj_or_model is not model and obj_pk is None:
-        obj_pk = str(obj_or_model.pk)
+
+    # try getting value of AleaIdField straight from instance if possible
+    if isinstance(obj_or_model, model):
+        # obj_or_model is an instance, not a model.
+        if isinstance(meta.pk, AleaIdField):
+            return obj_or_model.pk
+        alea_unique_fields = [
+            field
+            for field in meta.local_fields
+            if isinstance(field, AleaIdField) and field.unique
+        ]
+        if len(alea_unique_fields) == 1:
+            # found an AleaIdField with unique=True, assume it's got the value.
+            return getattr(obj_or_model, alea_unique_fields[0].attname)
+        if obj_pk is None:
+            # fall back to primary key, but coerce as string type for lookup.
+            obj_pk = str(obj_or_model.pk)
+
     if obj_pk is None:
+        # bail out if args are (model, pk) but pk is None.
         return None
+
+    # fallback to using AleaIdField from ObjectMapping model.
     content_type = ContentType.objects.get_for_model(model)
     try:
         return ObjectMapping.objects.values_list(
@@ -47,6 +66,13 @@ def get_meteor_id(obj_or_model, obj_pk=None):
 def get_meteor_ids(model, object_ids):
     """Return Alea ID mapping for all given ids of specified model."""
     content_type = ContentType.objects.get_for_model(model)
+    # Django model._meta is now public API -> pylint: disable=W0212
+    meta = model._meta
+    if isinstance(meta.pk, AleaIdField):
+        # primary_key is an AleaIdField, use it.
+        return collections.OrderedDict(
+            (obj_pk, obj_pk) for obj_pk in object_ids
+        )
     result = collections.OrderedDict(
         (str(obj_pk), None)
         for obj_pk
@@ -59,11 +85,10 @@ def get_meteor_ids(model, object_ids):
         result[obj_pk] = meteor_id
     for obj_pk, meteor_id in result.items():
         if meteor_id is None:
-            # Django model._meta is now public API -> pylint: disable=W0212
             result[obj_pk] = ObjectMapping.objects.create(
                 content_type=content_type,
                 object_id=obj_pk,
-                meteor_id=meteor_random_id('/collection/%s' % model._meta),
+                meteor_id=meteor_random_id('/collection/%s' % meta),
             ).meteor_id
     return result
 
@@ -71,10 +96,32 @@ def get_meteor_ids(model, object_ids):
 @transaction.atomic
 def get_object_id(model, meteor_id):
     """Return an object ID for the given meteor_id."""
+    if meteor_id is None:
+        return None
+    # Django model._meta is now public API -> pylint: disable=W0212
+    meta = model._meta
+
     if model is ObjectMapping:
         # this doesn't make sense - raise TypeError
         raise TypeError("Can't map ObjectMapping instances through self.")
-    # Django model._meta is now public API -> pylint: disable=W0212
+
+    if isinstance(meta.pk, AleaIdField):
+        # meteor_id is the primary key
+        return meteor_id
+
+    alea_unique_fields = [
+        field
+        for field in meta.local_fields
+        if isinstance(field, AleaIdField) and field.unique
+    ]
+    if len(alea_unique_fields) == 1:
+        # found an AleaIdField with unique=True, assume it's got the value.
+        return model.objects.values_list(
+            'pk', flat=True,
+        ).get(**{
+            alea_unique_fields[0].attname: meteor_id,
+        })
+
     content_type = ContentType.objects.get_for_model(model)
     return ObjectMapping.objects.filter(
         content_type=content_type,
@@ -85,6 +132,12 @@ def get_object_id(model, meteor_id):
 @transaction.atomic
 def get_object(model, meteor_id, *args, **kwargs):
     """Return an object for the given meteor_id."""
+    # Django model._meta is now public API -> pylint: disable=W0212
+    meta = model._meta
+    if isinstance(meta.pk, AleaIdField):
+        # meteor_id is the primary key
+        return model.objects.filter(*args, **kwargs).get(pk=meteor_id)
+
     return model.objects.filter(*args, **kwargs).get(
         pk=get_object_id(model, meteor_id),
     )
@@ -97,11 +150,41 @@ class AleaIdField(models.CharField):
     def __init__(self, *args, **kwargs):
         """Assume max_length of 17 to match Meteor implementation."""
         kwargs.update(
-            default=meteor_random_id,
+            editable=False,
             max_length=17,
         )
         super(AleaIdField, self).__init__(*args, **kwargs)
 
+    def deconstruct(self):
+        """Return details on how this field was defined."""
+        name, path, args, kwargs = super(AleaIdField, self).deconstruct()
+        del kwargs['max_length']
+        return name, path, args, kwargs
+
+    def pre_save(self, model_instance, add):
+        """Generate ID if required."""
+        _, _, _, kwargs = self.deconstruct()
+        val = getattr(model_instance, self.attname)
+        if val is None and kwargs.get('default', None) is None:
+            val = meteor_random_id('/collection/%s' % model_instance._meta)
+            setattr(model_instance, self.attname, val)
+        return val
+
+
+class AleaIdMixin(models.Model):
+
+    """Django model mixin that provides AleaIdField field (as _id)."""
+
+    id = AleaIdField(
+        primary_key=True,
+    )
+
+    class Meta(object):
+
+        """Model meta options for AleaIdMixin."""
+
+        abstract = True
+
 
 @python_2_unicode_compatible
 class ObjectMapping(models.Model):