class GraphQLServer

Public Class Methods

new(*args, type_def: nil, resolver: nil, schema: nil, context: nil) click to toggle source

Initilizes GraphQLServer as a Rack app or middleware

This Rack middleware (or app) implements a spec-compliant GraphQL server which can be queried from any GraphQL client. It can be used with a provided GraphQL schema or can build one from a type definition and a resolver hash.

@param [Array<Object>] *args The first argument should be `app` when used as a middleware @param String type_def A schema definition string, or a path to a file containing the definition @param Hash resolver A hash with callables for handling field resolution @param GraphQL::Schema schema Use this schema if `type_def` and `resolver` is nil @param Hash context

# File lib/graphql_server.rb, line 19
def initialize(*args, type_def: nil, resolver: nil, schema: nil, context: nil)
  @app = args && args[0]
  @context = context
  @schema = type_def && resolver ? GraphQL::Schema.from_definition(type_def, default_resolve: resolver) : schema
end

Public Instance Methods

call(env) click to toggle source

# File lib/graphql_server.rb, line 29
def call(env)
  request = Rack::Request.new(env)
  
  # graphql accepts GET and POST requests
  raise InvalidRequestType unless request.get? || request.post?

  payload = if request.get?
    request.params
  elsif request.post?
    body = request.body.read
    raise PostBodyMissing if body.empty?
    JSON.parse(body)
  end

  response = @schema.execute(
    payload['query'], 
    variables: payload['variables'],
    operation_name: payload['operationName'],
    context: @context, 
  ).to_json
  
  [200, {'Content-Type' => 'application/json', 'Content-Length' => response.bytesize.to_s}, [response]]
rescue InvalidRequestType
  # Method Not Allowed
  [405, {"Content-Type" => "text/html"}, ["GraphQL Server supports only GET/POST requests"]]
rescue PostBodyMissing
  # Bad Request
  [400, {"Content-Type" => "text/html"}, ["POST body missing"]]
end

middleware?() click to toggle source

# File lib/graphql_server.rb, line 25
def middleware?
  !@app.nil?
end