Wagtail API v2 Configuration Guide¶
This section of the docs will show you how to set up a public API for your Wagtail site.
Even though the API is built on Django REST Framework, you do not need to install this manually as it is already a dependency of Wagtail.
Basic configuration¶
Enable the app¶
Firstly, you need to enable Wagtail’s API app so Django can see it.
Add wagtail.api.v2
to INSTALLED_APPS
in your Django project settings:
# settings.py
INSTALLED_APPS = [
...
'wagtail.api.v2',
...
]
Optionally, you may also want to add rest_framework
to INSTALLED_APPS
.
This would make the API browsable when viewed from a web browser but is not
required for basic JSON-formatted output.
Configure endpoints¶
Next, it’s time to configure which content will be exposed on the API. Each content type (such as pages, images and documents) has its own endpoint. Endpoints are combined by a router, which provides the url configuration you can hook into the rest of your project.
Wagtail provides multiple endpoint classes you can use:
Pages
wagtail.api.v2.views.PagesAPIViewSet
Images
wagtail.images.api.v2.views.ImagesAPIViewSet
Documents
wagtail.documents.api.v2.views.DocumentsAPIViewSet
Redirects
wagtail.contrib.redirects.api.RedirectsAPIViewSet
see API
You can subclass any of these endpoint classes to customize their functionality.
For example, in this case, if you need to change the APIViewSet
by setting a desired renderer class:
from rest_framework.renderers import JSONRenderer
# ...
class CustomPagesAPIViewSet(PagesAPIViewSet):
renderer_classes = [JSONRenderer]
name = "pages"
api_router.register_endpoint("pages", CustomPagesAPIViewSet)
Or changing the desired model to use for page results.
from rest_framework.renderers import JSONRenderer
# ...
class PostPagesAPIViewSet(PagesAPIViewSet):
model = models.BlogPage
api_router.register_endpoint("posts", PostPagesAPIViewSet)
Additionally, there is a base endpoint class you can use for adding different
content types to the API: wagtail.api.v2.views.BaseAPIViewSet
For this example, we will create an API that includes all three builtin content types in their default configuration:
# api.py
from wagtail.api.v2.views import PagesAPIViewSet
from wagtail.api.v2.router import WagtailAPIRouter
from wagtail.images.api.v2.views import ImagesAPIViewSet
from wagtail.documents.api.v2.views import DocumentsAPIViewSet
# Create the router. "wagtailapi" is the URL namespace
api_router = WagtailAPIRouter('wagtailapi')
# Add the three endpoints using the "register_endpoint" method.
# The first parameter is the name of the endpoint (such as pages, images). This
# is used in the URL of the endpoint
# The second parameter is the endpoint class that handles the requests
api_router.register_endpoint('pages', PagesAPIViewSet)
api_router.register_endpoint('images', ImagesAPIViewSet)
api_router.register_endpoint('documents', DocumentsAPIViewSet)
Next, register the URLs so Django can route requests into the API:
# urls.py
from .api import api_router
urlpatterns = [
...
path('api/v2/', api_router.urls),
...
# Ensure that the api_router line appears above the default Wagtail page serving route
re_path(r'^', include(wagtail_urls)),
]
With this configuration, pages will be available at /api/v2/pages/
, images
at /api/v2/images/
and documents at /api/v2/documents/
Adding custom page fields¶
It’s likely that you would need to export some custom fields over the API. This
can be done by adding a list of fields to be exported into the api_fields
attribute for each page model.
For example:
# blog/models.py
from wagtail.api import APIField
class BlogPageAuthor(Orderable):
page = models.ForeignKey('blog.BlogPage', on_delete=models.CASCADE, related_name='authors')
name = models.CharField(max_length=255)
api_fields = [
APIField('name'),
]
class BlogPage(Page):
published_date = models.DateTimeField()
body = RichTextField()
feed_image = models.ForeignKey('wagtailimages.Image', on_delete=models.SET_NULL, null=True, ...)
private_field = models.CharField(max_length=255)
# Export fields over the API
api_fields = [
APIField('published_date'),
APIField('body'),
APIField('feed_image'),
APIField('authors'), # This will nest the relevant BlogPageAuthor objects in the API response
]
This will make published_date
, body
, feed_image
and a list of
authors
with the name
field available in the API. But to access these
fields, you must select the blog.BlogPage
type using the ?type
parameter in the API itself.
Adding form fields to the API¶
If you have a FormBuilder page called FormPage
this is an example of how you would expose the form fields to the API:
from wagtail.api import APIField
class FormPage(AbstractEmailForm):
#...
api_fields = [
APIField('form_fields'),
]
Custom serializers¶
Serializers are used to convert the database representation of a model into
JSON format. You can override the serializer for any field using the
serializer
keyword argument:
from rest_framework.fields import DateField
class BlogPage(Page):
...
api_fields = [
# Change the format of the published_date field to "Thursday 06 April 2017"
APIField('published_date', serializer=DateField(format='%A %d %B %Y')),
...
]
Django REST framework’s serializers can all take a source argument allowing you to add API fields that have a different field name or no underlying field at all:
from rest_framework.fields import DateField
class BlogPage(Page):
...
api_fields = [
# Date in ISO8601 format (the default)
APIField('published_date'),
# A separate published_date_display field with a different format
APIField('published_date_display', serializer=DateField(format='%A %d %B %Y', source='published_date')),
...
]
This adds two fields to the API (other fields omitted for brevity):
{
"published_date": "2017-04-06",
"published_date_display": "Thursday 06 April 2017"
}
Images in the API¶
The ImageRenditionField
serializer
allows you to add renditions of images into your API. It requires an image
filter string specifying the resize operations to perform on the image. It can
also take the source
keyword argument described above.
For example:
from wagtail.api import APIField
from wagtail.images.api.fields import ImageRenditionField
class BlogPage(Page):
...
api_fields = [
# Adds information about the source image (eg, title) into the API
APIField('feed_image'),
# Adds a URL to a rendered thumbnail of the image to the API
APIField('feed_image_thumbnail', serializer=ImageRenditionField('fill-100x100', source='feed_image')),
...
]
This would add the following to the JSON:
{
"feed_image": {
"id": 45529,
"meta": {
"type": "wagtailimages.Image",
"detail_url": "http://www.example.com/api/v2/images/12/",
"download_url": "/media/images/a_test_image.jpg",
"tags": []
},
"title": "A test image",
"width": 2000,
"height": 1125
},
"feed_image_thumbnail": {
"url": "/media/images/a_test_image.fill-100x100.jpg",
"full_url": "http://www.example.com/media/images/a_test_image.fill-100x100.jpg",
"width": 100,
"height": 100,
"alt": "image alt text"
}
}
Note: download_url
is the original uploaded file path, whereas
feed_image_thumbnail['url']
is the url of the rendered image.
When you are using another storage backend, such as S3, download_url
will return
a URL to the image if your media files are properly configured.
For cases where the source image set may contain SVGs, the ImageRenditionField
constructor takes a preserve_svg
argument. The behavior of ImageRenditionField
when preserve_svg
is True
is as described for the image
template tag’s preserve-svg
argument (see the documentation on SVG images).
Additional settings¶
WAGTAILAPI_BASE_URL
¶
(required when using frontend cache invalidation)
This is used in two places, when generating absolute URLs to document files and invalidating the cache.
Generating URLs to documents will fall back the current request’s hostname
if this is not set. Cache invalidation cannot do this, however, so this setting
must be set when using this module alongside the wagtailfrontendcache
module.
WAGTAILAPI_SEARCH_ENABLED
¶
(default: True)
Setting this to false will disable full text search. This applies to all endpoints.
WAGTAILAPI_LIMIT_MAX
¶
(default: 20)
This allows you to change the maximum number of results a user can request at a
time. This applies to all endpoints. Set to None
for no limit.