# GraphQL-compose [](https://www.npmjs.com/package/graphql-compose) [](https://codecov.io/github/graphql-compose/graphql-compose) [](https://travis-ci.org/graphql-compose/graphql-compose) [](http://www.npmtrends.com/graphql-compose) [](http://commitizen.github.io/cz-cli/)   [](#backers) [](#sponsors) [GraphQL](http://graphql.org/) – is a query language for APIs. [graphql-js](https://github.com/graphql/graphql-js) is the reference implementation of GraphQL for nodejs which introduce GraphQL type system for describing schema _(definition over configuration)_ and executes queries on the server side. [express-graphql](https://github.com/graphql/express-graphql) is a HTTP server which gets request data, passes it to `graphql-js` and returned result passes to response. **`graphql-compose`** – the _imperative tool_ which worked on top of `graphql-js`. It provides some methods for creating types and GraphQL Models (so I call types with a list of common resolvers) for further building of complex relations in your schema. * provides methods for editing GraphQL output/input types (add/remove fields/args/interfaces) * introduces `Resolver`s – the named graphql fieldConfigs, which can be used for finding, updating, removing records * provides an easy way for creating relations between types via `Resolver`s * provides converter from `OutputType` to `InputType` * provides `projection` parser from AST * provides `GraphQL schema language` for defining simple types * adds additional types `Date`, `Json` **`graphql-compose-[plugin]`** – is a _declarative generators/plugins_ that build on top of `graphql-compose`, which take some ORMs, schema definitions and creates GraphQL Models from them or modify existed GraphQL Types. Type generator plugins: * [graphql-compose-json](https://github.com/graphql-compose/graphql-compose-json) - generates GraphQL type from JSON (a good helper for wrapping REST APIs) * [graphql-compose-mongoose](https://github.com/graphql-compose/graphql-compose-mongoose) - generates GraphQL types from mongoose (MongoDB models) with Resolvers. * [graphql-compose-elasticsearch](https://github.com/graphql-compose/graphql-compose-elasticsearch) - generates GraphQL types from elastic mappings; ElasticSearch REST API proxy via GraphQL. * [graphql-compose-aws](https://github.com/graphql-compose/graphql-compose-aws) - expose AWS Cloud API via GraphQL Utility plugins: * [graphql-compose-relay](https://github.com/graphql-compose/graphql-compose-relay) - reassemble GraphQL types with `Relay` specific things, like `Node` type and interface, `globalId`, `clientMutationId`. * [graphql-compose-connection](https://github.com/graphql-compose/graphql-compose-connection) - generates `connection` Resolver from `findMany` and `count` Resolvers. * [graphql-compose-dataloader](https://github.com/stoffern/graphql-compose-dataloader) - add DataLoader to graphql-composer resolvers. ## Documentation [graphql-compose.github.io](https://graphql-compose.github.io/) ## Live Demos * [graphql-compose.herokuapp.com](https://graphql-compose.herokuapp.com/) - Live demo of GraphQL Server (9 models, 14 files, ~750 LOC) * [nodkz.github.io/relay-northwind](https://nodkz.github.io/relay-northwind) - Live demo of Relay client working with the server above (8 crazy pages, 47 files, ~3000 LOC) ## Example city.js ```js import { TypeComposer} from 'graphql-compose'; import { CountryTC } from './country'; export const CityTC = TypeComposer.create(` type City { code: String! name: String! population: Number countryCode: String tz: String } `); // Define some additional fields CityTC.addFields({ ucName: { // standard GraphQL like field definition type: GraphQLString, resolve: (source) => source.name.toUpperCase(), }, currentLocalTime: { // extended GraphQL Compose field definition type: 'Date', resolve: (source) => moment().tz(source.tz).format(), projection: { tz: true }, // load `tz` from database, when requested only `localTime` field }, counter: 'Int', // shortening for only type definition for field complex: `type ComplexType { subField1: String subField2: Float subField3: Boolean subField4: ID subField5: JSON subField6: Date }`, list0: { type: '[String]', description: 'Array of strings', }, list1: '[String]', list2: ['String'], list3: [new GraphQLOutputType(...)], list4: [`type Complex2Type { f1: Float, f2: Int }`], }); // Add resolver method CityTC.addResolver({ kind: 'query', name: 'findMany', args: { filter: `input CityFilterInput { code: String! }`, limit: { type: 'Int', defaultValue: 20, }, skip: 'Int', // ... other args if needed }, type: [CityTC], // array of cities resolve: async ({ args, context }) => { return context.someCityDB .findMany(args.filter) .limit(args.limit) .skip(args.skip); }, }); // Add relation between City and Country by `countryCode` field. CityTC.addRelation( // GraphQL relation definition 'country', { resolver: () => CountryTC.getResolver('findOne'), prepareArgs: { filter: source => ({ code: `${source.countryCode}` }), }, projection: { countryCode: true }, } ); // Remove `tz` field from schema CityTC.removeField('tz'); // Add description to field CityTC.extendField('name', { description: 'City name', }); ``` schema.js ```js import { schemaComposer } from 'graphql-compose'; import { CityTC } from './city'; import { CountryTC } from './country'; schemaComposer.Query.addFields({ cities: CityTC.getResolver('findMany'), country: CountryTC.getResolver('findOne'), currentTime: { type: 'Date', resolve: () => Date.now(), }, }); schemaComposer.Mutation.addFields({ createCity: CityTC.getResolver('createOne'), updateCity: CityTC.getResolver('updateById'), ...adminAccess({ removeCity: CityTC.getResolver('removeById'), }), }); function adminAccess(resolvers) { Object.keys(resolvers).forEach(k => { resolvers[k] = resolvers[k].wrapResolve(next => rp => { // rp = resolveParams = { source, args, context, info } if (!rp.context.isAdmin) { throw new Error('You should be admin, to have access to this action.'); } return next(rp); }); }); return resolvers; } export default schemaComposer.buildSchema(); ``` ## Contributors This project exists thanks to all the people who contribute. ## Backers Thank you to all our backers! 🙏 [[Become a backer](https://opencollective.com/graphql-compose#backer)] ## Sponsors Support this project by becoming a sponsor. Your logo will show up here with a link to your website. [[Become a sponsor](https://opencollective.com/graphql-compose#sponsor)] ## License [MIT](https://github.com/graphql-compose/graphql-compose/blob/master/LICENSE.md)