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 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 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: previously subscriptions were only enabled when Grapple was installed with Django Channels. We no longer provide out of the box support for subscriptions due to incompatibilities in the various dependencies. The register_schema_subscription hook is still provided. It is called when Grapple creates the schema. You can use it to add your custom Subscription mixins and functionality.

import asyncio
import graphene


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

    async def resolve_count_seconds(root, info, up_to):
        for i in range(up_to):
            yield i
            await asyncio.sleep(1.0)
        yield up_to

# your_app/wagtail_hooks.py
from .subscriptions import Subscription


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