Generators

If you’re using GraphQL with Ruby on Rails, you can use generators to:

• setup GraphQL, including GraphiQL, GraphQL::Batch, and Relay

• scaffold types

• scaffold Relay mutations

• scaffold ActiveRecord create/update/delete mutations

• scaffold GraphQL::Batch loaders

graphql:install

You can add GraphQL to a Rails app with graphql:install:

rails generate graphql:install

This will:

• Set up a folder structure in app/graphql/

• Add schema definition

• Add base type classes

• Add a Query type definition

• Add a Mutation type definition with a base mutation class

• Add a route and controller for executing queries

• Install graphiql-rails

• Enable ActiveRecord::QueryLogs and add GraphQL-related metadata (using GraphQL::Current)

After installing you can see your new schema by:

• bundle install

• rails server

• Open localhost:3000/graphiql

Options

• --directory=DIRECTORY will specify the directory where generated files should be saved (default is app/graphql)

• --schema=MySchemaName will be used for naming the schema (default is #{app_name}Schema)

• --skip-graphiql will exclude graphiql-rails from the setup

• --skip-mutation-root-type will not create of the mutation root type

• --skip-query-logs will skip the QueryLogs setup

• --relay will add Relay-specific code to your schema

• --batch will add GraphQL::Batch to your gemfile and include the setup in your schema

• --playground will include graphql_playground-rails in the setup (mounted at /playground)

• --api will create smaller stack for API only apps

Scaffolding Types

Several generators will add GraphQL types to your project. Run them with -h to see the options:

• rails g graphql:object

• rails g graphql:input

• rails g graphql:interface

• rails g graphql:union

• rails g graphql:enum

• rails g graphql:scalar

ActiveRecord columns auto-extraction

The graphql:object and graphql:input generators can detect the existence of an ActiveRecord class with the same name, and scaffold all database columns as fields/arguments using appropriate GraphQL types and nullability detection

Options

• --namespaced-types will generate each one of the object/input/interface/... types under separate Types::Objects::*/Types::Inputs::*/Types::Interfaces::*/... namespaces and folders

Scaffolding Mutations

You can prepare a Relay Classic mutation with

rails g graphql:mutation #{mutation_name}

Scaffolding ActiveRecord Mutations

You can generate a Relay Classic create, update or delete mutation for a given model with

rails g graphql:mutation_create #{model_class_name}
rails g graphql:mutation_update #{model_class_name}
rails g graphql:mutation_delete #{model_class_name}

model_class_name accepts both namespace/class_type and Namespace::ClassType formats. This mutation also accepts the --namespaced-types flag, to keep it consistent with the scaffolded Object and Input classes from the type generators

Scaffolding Loaders

You can prepare a GraphQL::Batch loader with

rails g graphql:loader