Relation fields move into relations.py

docs/api-guide/relations.md

+<a class="github" href="relations.py"></a>
+
+# Serializer relations
+
+> Bad programmers worry about the code.
+> Good programmers worry about data structures and their relationships.
+>
+> &mdash; [Linus Torvalds][cite]
+
+
+Relational fields are used to represent model relationships.  They can be applied to `ForeignKey`, `ManyToManyField` and `OneToOneField` relationships, as well as to reverse relationships, and custom relationships such as `GenericForeignKey`.
+
+---
+
+**Note:** The relational fields are declared in `relations.py`, but by convention you should import them using `from rest_framework import serializers` and refer to fields as `serializers.<FieldName>`.
+
+---
+
+## RelatedField
+
+This field can be applied to any of the following:
+
+* A `ForeignKey` field.
+* A `OneToOneField` field.
+* A reverse OneToOne relationship
+* Any other "to-one" relationship.
+
+By default `RelatedField` will represent the target of the field using it's `__unicode__` method.
+
+You can customize this behavior by subclassing `ManyRelatedField`, and overriding the `.to_native(self, value)` method.
+
+## ManyRelatedField
+
+This field can be applied to any of the following:
+ 
+* A `ManyToManyField` field.
+* A reverse ManyToMany relationship.
+* A reverse ForeignKey relationship
+* Any other "to-many" relationship.
+
+By default `ManyRelatedField` will represent the targets of the field using their `__unicode__` method.
+
+For example, given the following models:
+
+    class TaggedItem(models.Model):
+        """
+        Tags arbitrary model instances using a generic relation.
+        
+        See: https://docs.djangoproject.com/en/dev/ref/contrib/contenttypes/
+        """
+        tag = models.SlugField()
+        content_type = models.ForeignKey(ContentType)
+        object_id = models.PositiveIntegerField()
+        content_object = GenericForeignKey('content_type', 'object_id')
+    
+        def __unicode__(self):
+            return self.tag
+    
+    
+    class Bookmark(models.Model):
+        """
+        A bookmark consists of a URL, and 0 or more descriptive tags.
+        """
+        url = models.URLField()
+        tags = GenericRelation(TaggedItem)
+
+And a model serializer defined like this:
+
+    class BookmarkSerializer(serializers.ModelSerializer):
+        tags = serializers.ManyRelatedField(source='tags')
+
+        class Meta:
+            model = Bookmark
+            exclude = ('id',)
+
+Then an example output format for a Bookmark instance would be:
+
+    {
+        'tags': [u'django', u'python'],
+        'url': u'https://www.djangoproject.com/'
+    }
+
+## PrimaryKeyRelatedField
+## ManyPrimaryKeyRelatedField
+
+`PrimaryKeyRelatedField` and `ManyPrimaryKeyRelatedField` will represent the target of the relationship using it's primary key.
+
+By default these fields are read-write, although you can change this behavior using the `read_only` flag.
+
+**Arguments**:
+
+* `queryset` - By default `ModelSerializer` classes will use the default queryset for the relationship.  `Serializer` classes must either set a queryset explicitly, or set `read_only=True`.
+* `null` - If set to `True`, the field will accept values of `None` or the empty-string for nullable relationships.
+
+## SlugRelatedField
+## ManySlugRelatedField
+
+`SlugRelatedField` and `ManySlugRelatedField` will represent the target of the relationship using a unique slug.
+
+By default these fields read-write, although you can change this behavior using the `read_only` flag.
+
+**Arguments**:
+
+* `slug_field` - The field on the target that should be used to represent it.  This should be a field that uniquely identifies any given instance.  For example, `username`.
+* `queryset` - By default `ModelSerializer` classes will use the default queryset for the relationship.  `Serializer` classes must either set a queryset explicitly, or set `read_only=True`.
+* `null` - If set to `True`, the field will accept values of `None` or the empty-string for nullable relationships.
+
+## HyperlinkedRelatedField
+## ManyHyperlinkedRelatedField
+
+`HyperlinkedRelatedField` and `ManyHyperlinkedRelatedField` will represent the target of the relationship using a hyperlink.
+
+By default, `HyperlinkedRelatedField` is read-write, although you can change this behavior using the `read_only` flag.
+
+**Arguments**:
+
+* `view_name` - The view name that should be used as the target of the relationship.  **required**.
+* `format` - If using format suffixes, hyperlinked fields will use the same format suffix for the target unless overridden by using the `format` argument.
+* `queryset` - By default `ModelSerializer` classes will use the default queryset for the relationship.  `Serializer` classes must either set a queryset explicitly, or set `read_only=True`.
+* `slug_field` - The field on the target that should be used for the lookup. Default is `'slug'`.
+* `pk_url_kwarg` - The named url parameter for the pk field lookup. Default is `pk`.
+* `slug_url_kwarg` - The named url parameter for the slug field lookup. Default is to use the same value as given for `slug_field`.
+* `null` - If set to `True`, the field will accept values of `None` or the empty-string for nullable relationships.
+
+## HyperLinkedIdentityField
+
+This field can be applied as an identity relationship, such as the `'url'` field on  a HyperlinkedModelSerializer.
+
+This field is always read-only.
+
+**Arguments**:
+
+* `view_name` - The view name that should be used as the target of the relationship.  **required**.
+* `format` - If using format suffixes, hyperlinked fields will use the same format suffix for the target unless overridden by using the `format` argument.
+* `slug_field` - The field on the target that should be used for the lookup. Default is `'slug'`.
+* `pk_url_kwarg` - The named url parameter for the pk field lookup. Default is `pk`.
+* `slug_url_kwarg` - The named url parameter for the slug field lookup. Default is to use the same value as given for `slug_field`.
+
+[cite]: http://lwn.net/Articles/193245/

docs/index.md

@@ -94,6 +94,7 @@ The API guide is your complete reference manual to all the functionality provide
 * [Renderers][renderers]
 * [Serializers][serializers]
 * [Serializer fields][fields]
+* [Serializer relations][relations]
 * [Authentication][authentication]
 * [Permissions][permissions]
 * [Throttling][throttling]
@@ -185,6 +186,7 @@ OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 [renderers]: api-guide/renderers.md
 [serializers]: api-guide/serializers.md
 [fields]: api-guide/fields.md
+[relations]: api-guide/relations.md
 [authentication]: api-guide/authentication.md
 [permissions]: api-guide/permissions.md
 [throttling]: api-guide/throttling.md

docs/template.html

@@ -72,6 +72,7 @@
                   <li><a href="{{ base_url }}/api-guide/renderers{{ suffix }}">Renderers</a></li>
                   <li><a href="{{ base_url }}/api-guide/serializers{{ suffix }}">Serializers</a></li>
                   <li><a href="{{ base_url }}/api-guide/fields{{ suffix }}">Serializer fields</a></li>
+                  <li><a href="{{ base_url }}/api-guide/relations{{ suffix }}">Serializer relations</a></li>
                   <li><a href="{{ base_url }}/api-guide/authentication{{ suffix }}">Authentication</a></li>
                   <li><a href="{{ base_url }}/api-guide/permissions{{ suffix }}">Permissions</a></li>
                   <li><a href="{{ base_url }}/api-guide/throttling{{ suffix }}">Throttling</a></li>

rest_framework/serializers.py

@@ -14,7 +14,7 @@ from rest_framework.compat import get_concrete_model
 # This helps keep the seperation between model fields, form fields, and
 # serializer fields more explicit.
 
-
+from rest_framework.relations import *
 from rest_framework.fields import *