| /** |
| Licensed to the Apache Software Foundation (ASF) under one |
| or more contributor license agreements. See the NOTICE file |
| distributed with this work for additional information |
| regarding copyright ownership. The ASF licenses this file |
| to you under the Apache License, Version 2.0 (the |
| "License"); you may not use this file except in compliance |
| with the License. You may obtain a copy of the License at |
| |
| http://www.apache.org/licenses/LICENSE-2.0 |
| |
| Unless required by applicable law or agreed to in writing, |
| software distributed under the License is distributed on an |
| "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY |
| KIND, either express or implied. See the License for the |
| specific language governing permissions and limitations |
| under the License. |
| */ |
| |
| // Given a function and an array of values, creates a chain of promises that |
| // will sequentially execute func(args[i]). |
| // Returns a promise. |
| // |
| function Q_chainmap (args, func) { |
| return Promise.resolve().then(function (inValue) { |
| return args.reduce(function (soFar, arg) { |
| return soFar.then(function (val) { |
| return func(arg, val); |
| }); |
| }, Promise.resolve(inValue)); |
| }); |
| } |
| |
| // Behaves similar to Q_chainmap but gracefully handles failures. |
| // When a promise in the chain is rejected, it will call the failureCallback and then continue the processing, instead of stopping |
| function Q_chainmap_graceful (args, func, failureCallback) { |
| return Promise.resolve().then(function (inValue) { |
| return args.reduce(function (soFar, arg) { |
| return soFar.then(function (val) { |
| return func(arg, val); |
| }).catch(function (err) { |
| if (failureCallback) { |
| failureCallback(err); |
| } |
| }); |
| }, Promise.resolve(inValue)); |
| }); |
| } |
| |
| exports.Q_chainmap = Q_chainmap; |
| exports.Q_chainmap_graceful = Q_chainmap_graceful; |