github.com/snowblossomcoin/go-ethereum@v1.9.25/graphql/service.go (about)

     1  // Copyright 2019 The go-ethereum Authors
     2  // This file is part of the go-ethereum library.
     3  //
     4  // The go-ethereum library is free software: you can redistribute it and/or modify
     5  // it under the terms of the GNU Lesser General Public License as published by
     6  // the Free Software Foundation, either version 3 of the License, or
     7  // (at your option) any later version.
     8  //
     9  // The go-ethereum library is distributed in the hope that it will be useful,
    10  // but WITHOUT ANY WARRANTY; without even the implied warranty of
    11  // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
    12  // GNU Lesser General Public License for more details.
    13  //
    14  // You should have received a copy of the GNU Lesser General Public License
    15  // along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.
    16  
    17  package graphql
    18  
    19  import (
    20  	"github.com/ethereum/go-ethereum/internal/ethapi"
    21  	"github.com/ethereum/go-ethereum/node"
    22  	"github.com/graph-gophers/graphql-go"
    23  	"github.com/graph-gophers/graphql-go/relay"
    24  )
    25  
    26  // New constructs a new GraphQL service instance.
    27  func New(stack *node.Node, backend ethapi.Backend, cors, vhosts []string) error {
    28  	if backend == nil {
    29  		panic("missing backend")
    30  	}
    31  	// check if http server with given endpoint exists and enable graphQL on it
    32  	return newHandler(stack, backend, cors, vhosts)
    33  }
    34  
    35  // newHandler returns a new `http.Handler` that will answer GraphQL queries.
    36  // It additionally exports an interactive query browser on the / endpoint.
    37  func newHandler(stack *node.Node, backend ethapi.Backend, cors, vhosts []string) error {
    38  	q := Resolver{backend}
    39  
    40  	s, err := graphql.ParseSchema(schema, &q)
    41  	if err != nil {
    42  		return err
    43  	}
    44  	h := &relay.Handler{Schema: s}
    45  	handler := node.NewHTTPHandlerStack(h, cors, vhosts)
    46  
    47  	stack.RegisterHandler("GraphQL UI", "/graphql/ui", GraphiQL{})
    48  	stack.RegisterHandler("GraphQL", "/graphql", handler)
    49  	stack.RegisterHandler("GraphQL", "/graphql/", handler)
    50  
    51  	return nil
    52  }