Graphene Directives

Schema Directives implementation for graphene

---

Directive Locations Supported

• DirectiveLocation.SCHEMA
• DirectiveLocation.OBJECT
• DirectiveLocation.ENUM
• DirectiveLocation.INTERFACE
• DirectiveLocation.UNION
• DirectiveLocation.SCALAR
• DirectiveLocation.FIELD_DEFINITION
• DirectiveLocation.INPUT_FIELD_DEFINITION
• DirectiveLocation.INPUT_OBJECT
• DirectiveLocation.ENUM_VALUE
• DirectiveLocation.ARGUMENT_DEFINITION,

---

Example

Using @directive

import graphene
from graphql import (
    GraphQLArgument,
    GraphQLInt,
    GraphQLNonNull,
    GraphQLString,
)

from graphene_directives import CustomDirective, DirectiveLocation, build_schema, directive

CacheDirective = CustomDirective(
    name="cache",
    locations=[DirectiveLocation.FIELD_DEFINITION, DirectiveLocation.OBJECT],
    args={
        "max_age": GraphQLArgument(
            GraphQLNonNull(GraphQLInt),
            description="Specifies the maximum age for cache in seconds.",
        ),
        "swr": GraphQLArgument(
            GraphQLInt, description="Stale-while-revalidate value in seconds. Optional."
        ),
        "scope": GraphQLArgument(
            GraphQLString, description="Scope of the cache. Optional."
        ),
    },
    description="Caching directive to control cache behavior of fields or fragments.",
)


@directive(CacheDirective, max_age=200)
class SomeType(graphene.ObjectType):
    field_1 = directive(CacheDirective, field=graphene.String(), max_age=300)
    field_2 = directive(CacheDirective, field=graphene.String(), max_age=300, swr=2)
    field_3 = graphene.String()


class Query(graphene.ObjectType):
    some_query = graphene.Field(SomeType)


schema = build_schema(
    query=Query, directives=[CacheDirective]
) 

Using directive_decorator

import graphene
from graphql import (
    GraphQLArgument,
    GraphQLInt,
    GraphQLNonNull,
    GraphQLString,
)

from graphene_directives import CustomDirective, DirectiveLocation, build_schema, directive_decorator

CacheDirective = CustomDirective(
    name="cache",
    locations=[DirectiveLocation.FIELD_DEFINITION, DirectiveLocation.OBJECT],
    args={
        "max_age": GraphQLArgument(
            GraphQLNonNull(GraphQLInt),
            description="Specifies the maximum age for cache in seconds.",
        ),
        "swr": GraphQLArgument(
            GraphQLInt, description="Stale-while-revalidate value in seconds. Optional."
        ),
        "scope": GraphQLArgument(
            GraphQLString, description="Scope of the cache. Optional."
        ),
    },
    description="Caching directive to control cache behavior of fields or fragments.",
)

# This returns a partial of directive function
cache = directive_decorator(target_directive=CacheDirective)


@cache(max_age=200)
class SomeType(graphene.ObjectType):
    field_1 = cache(field=graphene.String(), max_age=300)
    field_2 = cache(field=graphene.String(), max_age=300, swr=2)
    field_3 = graphene.String()


class Query(graphene.ObjectType):
    some_query = graphene.Field(SomeType)


schema = build_schema(
    query=Query, directives=[CacheDirective]
)

Custom Input Validation

from typing import Any

import graphene
from graphql import (
    GraphQLArgument,
    GraphQLInt,
    GraphQLNonNull,
    GraphQLString,
)

from graphene_directives import CustomDirective, DirectiveLocation, Schema, build_schema, directive_decorator


def input_transform(inputs: dict, _schema: Schema) -> dict:
    """
    def input_transform (inputs: Any, schema: Schema) -> dict,
    """
    if inputs.get("max_age") > 200:
        inputs["swr"] = 30
    return inputs


def validate_non_field_input(_type: Any, inputs: dict, _schema: Schema) -> bool:
    """
    def validator (type_: graphene type, inputs: Any, schema: Schema) -> bool,
    if validator returns False, library raises DirectiveCustomValidationError
    """
    if inputs.get("max_age") > 2500:
        return False
    return True


def validate_field_input(
        _parent_type: Any, _field_type: Any, inputs: dict, _schema: Schema
) -> bool:
    """
    def validator (parent_type_: graphene_type, field_type_: graphene type, inputs: Any, schema: Schema) -> bool,
    if validator returns False, library raises DirectiveCustomValidationError
    """
    if inputs.get("max_age") > 2500:
        return False
    return True


CacheDirective = CustomDirective(
    name="cache",
    locations=[DirectiveLocation.FIELD_DEFINITION, DirectiveLocation.OBJECT],
    args={
        "max_age": GraphQLArgument(
            GraphQLNonNull(GraphQLInt),
            description="Specifies the maximum age for cache in seconds.",
        ),
        "swr": GraphQLArgument(
            GraphQLInt, description="Stale-while-revalidate value in seconds. Optional."
        ),
        "scope": GraphQLArgument(
            GraphQLString, description="Scope of the cache. Optional."
        ),
    },
    description="Caching directive to control cache behavior of fields or fragments.",
    non_field_validator=validate_non_field_input,
    field_validator=validate_field_input,
    input_transform=input_transform,
)

# This returns a partial of directive function
cache = directive_decorator(target_directive=CacheDirective)


@cache(max_age=200)
class SomeType(graphene.ObjectType):
    field_1 = cache(field=graphene.String(), max_age=300)
    field_2 = cache(field=graphene.String(), max_age=300, swr=2)
    field_3 = graphene.String()


class Query(graphene.ObjectType):
    some_query = graphene.Field(SomeType)


schema = build_schema(
    query=Query, directives=[CacheDirective]
)

Complex Use Cases

Refer Code and Graphql Output