Updated to use APIField class in api_fields

Thanks to @BertrandBordage for the suggestion!

wagtail/api/__init__.py

@@ -1 +1,4 @@
+from .conf import APIField  # noqa
+
+
 default_app_config = 'wagtail.api.apps.WagtailAPIAppConfig'

wagtail/api/conf.py

@@ -0,0 +1,13 @@
+from __future__ import absolute_import, unicode_literals
+
+
+class APIField(object):
+    def __init__(self, name, serializer=None):
+        self.name = name
+        self.serializer = serializer
+
+    def __hash__(self):
+        return hash(self.name)
+
+    def __repr__(self):
+        return '<APIField {}>'.format(self.name)

wagtail/api/v2/endpoints.py

@@ -13,6 +13,7 @@ from rest_framework.renderers import BrowsableAPIRenderer, JSONRenderer
 from rest_framework.response import Response
 from rest_framework.viewsets import GenericViewSet
 
+from wagtail.api import APIField
 from wagtail.wagtailcore.models import Page
 
 from .filters import (
@@ -103,7 +104,7 @@ class BaseAPIEndpoint(GenericViewSet):
 
         if hasattr(model, 'api_fields'):
             fields.extend([
-                field[0] if isinstance(field, tuple) else field
+                field.name if isinstance(field, APIField) else field
                 for field in model.api_fields
             ])
 
@@ -119,7 +120,7 @@ class BaseAPIEndpoint(GenericViewSet):
 
         if hasattr(model, 'api_meta_fields'):
             meta_fields.extend([
-                field[0] if isinstance(field, tuple) else field
+                field.name if isinstance(field, APIField) else field
                 for field in model.api_meta_fields
             ])
 
@@ -131,16 +132,16 @@ class BaseAPIEndpoint(GenericViewSet):
 
         if hasattr(model, 'api_fields'):
             configs.update({
-                field[0]: field[1]
+                field.name: field.serializer
                 for field in model.api_fields
-                if isinstance(field, tuple)
+                if isinstance(field, APIField) and field.serializer is not None
             })
 
         if hasattr(model, 'api_meta_fields'):
             configs.update({
-                field[0]: field[1]
+                field.name: field.serializer
                 for field in model.api_meta_fields
-                if isinstance(field, tuple)
+                if isinstance(field, APIField) and field.serializer is not None
             })
 
         return configs

wagtail/tests/demosite/models.py

@@ -7,17 +7,17 @@ from modelcluster.contrib.taggit import ClusterTaggableManager
 from modelcluster.fields import ParentalKey
 from taggit.models import TaggedItemBase
 
+from wagtail.api import APIField
 from wagtail.utils.pagination import paginate
 from wagtail.wagtailadmin.edit_handlers import (
     FieldPanel, InlinePanel, MultiFieldPanel, PageChooserPanel)
 from wagtail.wagtailcore.fields import RichTextField
 from wagtail.wagtailcore.models import Orderable, Page
 from wagtail.wagtaildocs.edit_handlers import DocumentChooserPanel
+from wagtail.wagtailimages.api.fields import ImageRenditionField
 from wagtail.wagtailimages.edit_handlers import ImageChooserPanel
 from wagtail.wagtailsearch import index
 
-from wagtail.wagtailimages.api.fields import ImageRenditionField
-
 
 # ABSTRACT MODELS
 # =============================
@@ -278,13 +278,13 @@ class BlogEntryPage(Page):
     )
 
     api_fields = (
-        'body',
-        'tags',
-        'date',
-        'feed_image',
-        ('feed_image_thumbnail', ImageRenditionField('fill-300x300', source='feed_image')),
-        'carousel_items',
-        'related_links',
+        APIField('body'),
+        APIField('tags'),
+        APIField('date'),
+        APIField('feed_image'),
+        APIField('feed_image_thumbnail', serializer=ImageRenditionField('fill-300x300', source='feed_image')),
+        APIField('carousel_items'),
+        APIField('related_links'),
     )
 
     search_fields = Page.search_fields + [