# lib/goog/net/xmlhttpfactory.js

1 | // Copyright 2010 The Closure Library Authors. All Rights Reserved.
2 | //
3 | // Licensed under the Apache License, Version 2.0 (the "License");
4 | // you may not use this file except in compliance with the License.
5 | // You may obtain a copy of the License at
6 | //
7 | // http://www.apache.org/licenses/LICENSE-2.0
8 | //
9 | // Unless required by applicable law or agreed to in writing, software
10 | // distributed under the License is distributed on an "AS-IS" BASIS,
11 | // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
12 | // See the License for the specific language governing permissions and
13 | // limitations under the License.
14 |
15 | /**
16 | * @fileoverview Interface for a factory for creating XMLHttpRequest objects
17 | * and metadata about them.
18 | * @author dbk@google.com (David Barrett-Kahn)
19 | */
20 |
21 | goog.provide('goog.net.XmlHttpFactory');
22 |
23 | /** @suppress {extraRequire} Typedef. */
24 | goog.require('goog.net.XhrLike');
25 |
26 |
27 |
28 | /**
29 | * Abstract base class for an XmlHttpRequest factory.
30 | * @constructor
31 | */
32 | goog.net.XmlHttpFactory = function() {
33 | };
34 |
35 |
36 | /**
37 | * Cache of options - we only actually call internalGetOptions once.
38 | * @type {Object}
39 | * @private
40 | */
41 | goog.net.XmlHttpFactory.prototype.cachedOptions_ = null;
42 |
43 |
44 | /**
45 | * @return {!goog.net.XhrLike.OrNative} A new XhrLike instance.
46 | */
47 | goog.net.XmlHttpFactory.prototype.createInstance = goog.abstractMethod;
48 |
49 |
50 | /**
51 | * @return {Object} Options describing how xhr objects obtained from this
52 | * factory should be used.
53 | */
54 | goog.net.XmlHttpFactory.prototype.getOptions = function() {
55 | return this.cachedOptions_ ||
56 | (this.cachedOptions_ = this.internalGetOptions());
57 | };
58 |
59 |
60 | /**
61 | * Override this method in subclasses to preserve the caching offered by
62 | * getOptions().
63 | * @return {Object} Options describing how xhr objects obtained from this
64 | * factory should be used.
65 | * @protected
66 | */
67 | goog.net.XmlHttpFactory.prototype.internalGetOptions = goog.abstractMethod;