query.js

/*
 * Chaincode query
 */
"use strict";

var Fabric_Client = require("fabric-client");
var path = require("path");
var creds = require("./creds.json");

function y() {}

const obj2 = new y();
obj2.constructor.prototype.queryn = accessChain;

module.exports = obj2;

function accessChain(data) {
    return new Promise(resolve => {
    console.log(data);

    var fabric_client = new Fabric_Client();
    // setup the fabric network
    var channel = fabric_client.newChannel("defaultchannel");
    var peer = fabric_client.newPeer(creds.peers["org1-peer1"].url, {
        pem: creds.peers["org1-peer1"].tlsCACerts.pem,
        "ssl-target-name-override": null
    });
    channel.addPeer(peer);

    var member_user = null;
    var store_path = path.join(__dirname, "hfc-key-store");
    console.log("Store path:" + store_path);

    // create the key value store as defined in the fabric-client/config/default.json 'key-value-store' setting
    return Fabric_Client.newDefaultKeyValueStore({
        path: store_path
    }).then(state_store => {

            // assign the store to the fabric client
            fabric_client.setStateStore(state_store);
            var crypto_suite = Fabric_Client.newCryptoSuite();
            // use the same location for the state store (where the users' certificate are kept)
            // and the crypto store (where the users' keys are kept)
            var crypto_store = Fabric_Client.newCryptoKeyStore({
                path: store_path
            });
            crypto_suite.setCryptoKeyStore(crypto_store);
            fabric_client.setCryptoSuite(crypto_suite);

            // get the enrolled user from persistence, this user will sign all requests
            return fabric_client.getUserContext("user", true);
        }).then(user_from_store => {

            if (user_from_store && user_from_store.isEnrolled()) {
                console.log("Successfully loaded user1 from persistence");
                member_user = user_from_store;
            } else {
                throw new Error("Failed to get user1.... run registerUser.js");
            }

            // query chaincode function - requires 1 argument, ex: args: ['memberA@acme.org'],
            // you can query by any key that is written on to the ledger
            const request = {
                //targets : --- letting this default to the peers assigned to the channel
                chaincodeId: "cv3",
                fcn: "query",
                args: [data]
            };

            // send the query proposal to the peer
            return channel.queryByChaincode(request);
        }).then(query_responses => {

            console.log("Query has completed, checking results");
            // query_responses could have more than one  results if there multiple peers were used as targets
            if (query_responses && query_responses.length == 1) {
                if (query_responses[0] instanceof Error) {
                    console.error("error from query = ", query_responses[0]);
			        resolve({ success: false, message: query_responses[0] });
                } else {
                    // console.log("Response is ", query_responses[0].toString());
                    console.log('Q response --- > ' + query_responses[0]);

                    resolve({ success: true, message: query_responses[0].toString() });
                }
            } else {
                console.log("No payloads were returned from query");
                resolve({ success: false, message: "ERROR" });

            }
        })
        .catch(err => {
            console.error("Failed to query successfully :: " + err);
        });
    })
}