graphql

A work-in-progress implementation of GraphQL for Go.

Getting Started

To install the library, run:

go get github.com/graphql-go/graphql

The following is a simple example which defines a schema with a single hello string-type field and a Resolve method which returns the string world. A GraphQL query is performed against this schema with the resulting output printed in JSON format.

package main

import (
	"encoding/json"
	"fmt"
	"log"

	"github.com/graphql-go/graphql"
)

func main() {
	// Schema
	fields := graphql.FieldConfigMap{
		"hello": &graphql.FieldConfig{
			Type: graphql.String,
			Resolve: func(p graphql.GQLFRParams) interface{} {
				return "world"
			},
		},
	}
	rootQuery := graphql.ObjectConfig{Name: "RootQuery", Fields: fields}
	schemaConfig := graphql.SchemaConfig{Query: graphql.NewObject(rootQuery)}
	schema, err := graphql.NewSchema(schemaConfig)
	if err != nil {
		log.Fatalf("failed to create new schema, error: %v", err)
	}

	// Query
	query := `
		{
			hello
		}
	`
	params := graphql.Params{Schema: schema, RequestString: query}
	r := graphql.Graphql(params)
	if len(r.Errors) > 0 {
		log.Fatalf("failed to execute graphql operation, errors: %+v", r.Errors)
	}
	rJSON, _ := json.Marshal(r)
	fmt.Printf("%s \n", rJSON) // {“data”:{“hello”:”world”}}
}

For more complex examples, refer to the examples/ directory and graphql_test.go.

Origin and Current Direction

This project was originally a port of v0.4.3 of graphql-js (excluding the Validator), which was based on the July 2015 GraphQL specification. graphql is currently several versions behind graphql-js, however future efforts will be guided directly by the latest formal GraphQL specification (currently: October 2015).

Third Party Libraries

Name	Author	Description
graphql-go-handler	Hafiz Ismail	Middleware to handle GraphQL queries through HTTP requests.
graphql-relay-go	Hafiz Ismail	Lib to construct a graphql-go server supporting react-relay.
golang-relay-starter-kit	Hafiz Ismail	Barebones starting point for a Relay application with Golang GraphQL server.

Blog Posts

• Golang + GraphQL + Relay

Roadmap

• Lexer
• Parser
• Schema Parser
• Printer
• Schema Printer
• Visitor
• Executor
• Validator
• Examples
  • Basic Usage (see: PR-#21)
  • React/Relay
• Alpha Release (v0.1)

The Validator is optional, per official GraphQL specification, but it would be a useful addition.