edison-giphy-js-sdk-core/lib/handlers/RequestHandler.js

The **Giphy Core SDK** is a wrapper around [Giphy API](https://github.com/Giphy/GiphyAPI).

'use strict';

/*
 * Created by Cosmo Cochrane on 4/20/17.
 * Copyright (c) 2017 Giphy Inc.
 *
 * This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this
 * file, You can obtain one at http://mozilla.org/MPL/2.0/.
 */

var ResponseHandler = require('./ResponseHandler');
require('es6-promise').polyfill();
if (typeof fetch === 'undefined') {
  require('isomorphic-fetch');
}

function RequestHandler(vals, endpoint, cb) {

  function req(args, cb) {
    var canceled = false;
    var query_params_string = "?";

    Object.keys(args.params).forEach(function (key) {
      query_params_string = query_params_string.concat(key + "=" + args.params[key] + "&");
    });

    var constructedRequest = new Promise(function (resolve, reject) {
      if (vals.type && vals.type !== 'gifs' && vals.type !== 'stickers') {
        reject("The type argument was passed in incorrectly. It should be either 'gifs' or 'stickers'");
      }

      fetch(args.url + query_params_string, {
        method: args.method
      }).then(function (response) {
        //calling the end function will send the actual request 
        if (canceled === true) {
          return;
        } else {
          response.json().then(function (data) {
            ResponseHandler(response, data, function (res) {
              resolve(res);
              if (cb !== undefined) {
                cb(res, null);
              }
            }, function (err) {
              reject(err);
              if (cb !== undefined) {
                cb(null, err);
              }
            }, endpoint); //pass in args.url so you can determine before resolving the promise what request was just made
            // we pass the response to our helper method imported from ./helpers/
          });
        }
      }).catch(function (err) {
        reject(err);
      });
    });
    //allows users to cancel outgoing requests
    constructedRequest.cancel = function () {
      canceled = true;
    };

    return constructedRequest;
  }

  return req(vals, cb);
  //return the promise
}

module.exports = RequestHandler;