Hooks¶

On loading, Wagtail will search for any app with the file wagtail_hooks.py and execute the contents. This provides a way to register your own functions to execute at certain points in Wagtail’s execution. Read more about hooks in the Wagtail docs

Query¶

Grapple provides a register_schema_query hook that is called when it creates the schema. You can use it to add your custom Query mixins:

# your_app/wagtail_hooks.py
from wagtail.core import hooks
from your_app.queries import CustomQuery

@hooks.register('register_schema_query')
def add_my_custom_query(query_mixins):
    query_mixins.append(CustomQuery())  # if defined as mixin, or just CustomQuery if defined as a class

replace or remove any of the default mixins that are not of use in your project:

# your_app/wagtail_hooks.py
from wagtail.core import hooks
from grapple.types.search import SearchQuery
from .queries import ReplacementQuery

@hooks.register('register_schema_query')
def remove_search_query(query_mixins):
    query_mixins[:] = [item for item in query_mixins if item != SearchQuery]

@hooks.register('register_schema_query')
def replace_search_query(query_mixins):
    query_mixins[:] = [item for item in query_mixins if item != SearchQuery]
    query_mixins.append(ReplacementQuery)

Mutation¶

Grapple provides a register_schema_mutation hook that is called when it creates the schema. You can use it to add your custom Mutation mixins.

# your_app/mutations.py
class CreateAuthor(graphene.Mutation):
    class Arguments:
        name = graphene.String()
        parent = graphene.Int()

    ok = graphene.Boolean()
    author = graphene.Field(
        PageInterface,
    )

    def mutate(root, info, name, parent):
        author = AuthorPage(name=name, title=name, slug=name)
        ok = True
        Page.objects.get(id=parent).add_child(instance=author)
        author.save_revision().publish()
        return CreateAuthor(author=author, ok=ok)


class Mutation(graphene.ObjectType):
    create_author = CreateAuthor.Field()

# your_app/wagtail_hooks.py
from .mutations import Mutation

@hooks.register("register_schema_mutation")
def register_author_mutation(mutation_mixins):
    mutation_mixins.append(Mutation)

Subscription¶

Note: subscriptions are only enabled when Grapple is installed with Django Channels: pip install wagtail_grapple[channels]. Grapple provides a register_schema_subscription hook that is called when it creates the schema. You can use it to add your custom Subscription mixins

# your_app/subscriptions.py
import graphene
from rx import Observable

class Subscription(graphene.ObjectType):
    hello = graphene.String()

    def resolve_hello(root, info):
        return Observable.interval(3000).map(lambda i: "hello world!")

# your_app/wagtail_hooks.py
from .subscriptions import Subscription

@hooks.register("register_schema_subscription")
def register_example_subscription(subscription_mixins):
    subscription_mixins.append(Subscription)