graphene/docs/pages/docs/resolvers.md

title	description
Resolvers	Walkthrough Resolvers

Resolvers

A resolver is a method that resolves certain field within a ObjectType. The resolver of a field will be, if not specified otherwise, the resolve_{field_name} within the ObjectType.

By default a resolver will take the args, and info arguments. This is likely to be simplified in the future.

Quick example

This example model defines a Query type, which has a reverse field that reverses the given word argument using the resolve_reverse method in the class.

import graphene

class Query(graphene.ObjectType):
    reverse = graphene.String(word=graphene.String())

    def resolve_reverse(self, args, info):
        word = args.get('word')
        return word[::-1]

Resolvers outside the class

A field could also specify a custom resolver outside the class:

import graphene

def reverse(root, args, info):
    word = args.get('word')
    return word[::-1]

class Query(graphene.ObjectType):
    reverse = graphene.String(word=graphene.String(), resolver=reverse)

Context

A query in a GraphQL schema could have some context that we can use in any resolver. In this case we need to decorate the resolver function with with_context.

class Query(graphene.ObjectType):
    name = graphene.String()

    @with_context
    def resolve_name(self, args, context, info):
        return context['name']


result = schema.execute(query, context_value={'name': 'Peter'})