graphqlws

Implementation of the GraphQL over WebSocket protocol in Go. Brought to you by Functional Foundry.

API Documentation

Getting started

1. Install dependencies:

   go get github.com/sirupsen/logrus
   go get github.com/x-cray/logrus-prefixed-formatter
   go get github.com/google/uuid
   go get github.com/gorilla/websocket
   go get github.com/graphql-go/graphql

2. Clone the repository:

   mkdir -p "$GOPATH/src/github.com/functionalfoundry"
   cd "$GOPATH/src/github.com/functionalfoundry"
   git clone https://github.com/functionalfoundry/graphqlws

3. Run the tests:

   cd graphqlws
   go test

4. Run the example server:

   go run graphqlws/examples/server

Usage

Setup

package main

import (
	"net/http"

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

func main() {
	// Create a GraphQL schema
	schema, err := graphql.NewSchema(...)

	// Create a subscription manager
	subscriptionManager := graphqlws.NewSubscriptionManager(&schema)

	// Create a WebSocket/HTTP handler
	graphqlwsHandler := graphqlws.NewHandler(graphqlws.HandlerConfig{
		// Wire up the GraphqL WebSocket handler with the subscription manager
		SubscriptionManager: subscriptionManager,

		// Optional: Add a hook to resolve auth tokens into users that are
		// then stored on the GraphQL WS connections
		Authenticate: func(authToken string) (interface{}, error) {
			// This is just a dumb example
			return "Joe", nil
		},
	})

	// The handler integrates seamlessly with existing HTTP servers
	http.Handle("/subscriptions", graphqlwsHandler)
	http.ListenAndServe(":8080", nil)
}

Working with subscriptions

// This assumes you have access to the above subscription manager
subscriptions := subscriptionManager.Subscriptions()

for conn, _ := range subscriptions {
	// Things you have access to here:
	conn.ID()   // The connection ID
	conn.User() // The user returned from the Authenticate function

	for _, subscription := range subscriptions[conn] {
		// Things you have access to here:
		subscription.ID            // The subscription ID (unique per conn)
		subscription.OperationName // The name of the operation
		subscription.Query         // The subscription query/queries string
		subscription.Variables     // The subscription variables
		subscription.Document      // The GraphQL AST for the subscription
		subscription.Fields        // The names of top-level queries
		subscription.Connection    // The GraphQL WS connection

		// Prepare an execution context for running the query
		ctx := context.Context()

		// Re-execute the subscription query
		params := graphql.Params{
			Schema:         schema, // The GraphQL schema
			RequestString:  subscription.Query,
			VariableValues: subscription.Variables,
			OperationName:  subscription.OperationName,
			Context:        ctx,
		}
		result := graphql.Do(params)

		// Send query results back to the subscriber at any point
		data := graphqlws.DataMessagePayload{
			// Data can be anything (interface{})
			Data:   result.Data,
			// Errors is optional ([]error)
			Errors: graphqlws.ErrorsFromGraphQLErrors(result.Errors),
		}
		subscription.SendData(&data)
	}
}

Logging

graphqlws uses logrus for logging. In the future we might remove those logs entirely to leave logging entirely to developers using graphqlws. Given the current solution, you can control the logging level of graphqlws by setting it through logrus:

import (
  log "github.com/sirupsen/logrus"
)

...

log.SetLevel(log.WarnLevel)

License

Copyright © 2017-2018 Functional Foundry, LLC.

Licensed under the MIT License.