selenium-webdriver
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The official WebDriver JavaScript bindings from the Selenium project
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<!DOCTYPE html><meta charset="UTF-8"><meta http-equiv="Content-Language" content="en" /><title>promise.js</title><link href="../../../dossier.css" rel="stylesheet" type="text/css"><div id="main-wrapper"><input type="checkbox" id="sidenav-toggle" /><main><header><h1>lib/webdriver/promise.js</h1></header><pre><table class="srcfile"><tbody><tr><td><a name="l1" href="#l1">1</a><td>// Copyright 2011 Software Freedom Conservancy. All Rights Reserved.<tr><td><a name="l2" href="#l2">2</a><td>//<tr><td><a name="l3" href="#l3">3</a><td>// Licensed under the Apache License, Version 2.0 (the "License");<tr><td><a name="l4" href="#l4">4</a><td>// you may not use this file except in compliance with the License.<tr><td><a name="l5" href="#l5">5</a><td>// You may obtain a copy of the License at<tr><td><a name="l6" href="#l6">6</a><td>//<tr><td><a name="l7" href="#l7">7</a><td>// http://www.apache.org/licenses/LICENSE-2.0<tr><td><a name="l8" href="#l8">8</a><td>//<tr><td><a name="l9" href="#l9">9</a><td>// Unless required by applicable law or agreed to in writing, software<tr><td><a name="l10" href="#l10">10</a><td>// distributed under the License is distributed on an "AS IS" BASIS,<tr><td><a name="l11" href="#l11">11</a><td>// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.<tr><td><a name="l12" href="#l12">12</a><td>// See the License for the specific language governing permissions and<tr><td><a name="l13" href="#l13">13</a><td>// limitations under the License.<tr><td><a name="l14" href="#l14">14</a><td><tr><td><a name="l15" href="#l15">15</a><td>/**<tr><td><a name="l16" href="#l16">16</a><td> * @license Portions of this code are from the Dojo toolkit, received under the<tr><td><a name="l17" href="#l17">17</a><td> * BSD License:<tr><td><a name="l18" href="#l18">18</a><td> * Redistribution and use in source and binary forms, with or without<tr><td><a name="l19" href="#l19">19</a><td> * modification, are permitted provided that the following conditions are met:<tr><td><a name="l20" href="#l20">20</a><td> *<tr><td><a name="l21" href="#l21">21</a><td> * * Redistributions of source code must retain the above copyright notice,<tr><td><a name="l22" href="#l22">22</a><td> * this list of conditions and the following disclaimer.<tr><td><a name="l23" href="#l23">23</a><td> * * Redistributions in binary form must reproduce the above copyright notice,<tr><td><a name="l24" href="#l24">24</a><td> * this list of conditions and the following disclaimer in the documentation<tr><td><a name="l25" href="#l25">25</a><td> * and/or other materials provided with the distribution.<tr><td><a name="l26" href="#l26">26</a><td> * * Neither the name of the Dojo Foundation nor the names of its contributors<tr><td><a name="l27" href="#l27">27</a><td> * may be used to endorse or promote products derived from this software<tr><td><a name="l28" href="#l28">28</a><td> * without specific prior written permission.<tr><td><a name="l29" href="#l29">29</a><td> *<tr><td><a name="l30" href="#l30">30</a><td> * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"<tr><td><a name="l31" href="#l31">31</a><td> * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE<tr><td><a name="l32" href="#l32">32</a><td> * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE<tr><td><a name="l33" href="#l33">33</a><td> * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE<tr><td><a name="l34" href="#l34">34</a><td> * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR<tr><td><a name="l35" href="#l35">35</a><td> * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF<tr><td><a name="l36" href="#l36">36</a><td> * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS<tr><td><a name="l37" href="#l37">37</a><td> * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN<tr><td><a name="l38" href="#l38">38</a><td> * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)<tr><td><a name="l39" href="#l39">39</a><td> * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE<tr><td><a name="l40" href="#l40">40</a><td> * POSSIBILITY OF SUCH DAMAGE.<tr><td><a name="l41" href="#l41">41</a><td> */<tr><td><a name="l42" href="#l42">42</a><td><tr><td><a name="l43" href="#l43">43</a><td>/**<tr><td><a name="l44" href="#l44">44</a><td> * @fileoverview A promise implementation based on the CommonJS promise/A and<tr><td><a name="l45" href="#l45">45</a><td> * promise/B proposals. For more information, see<tr><td><a name="l46" href="#l46">46</a><td> * http://wiki.commonjs.org/wiki/Promises.<tr><td><a name="l47" href="#l47">47</a><td> */<tr><td><a name="l48" href="#l48">48</a><td><tr><td><a name="l49" href="#l49">49</a><td>goog.provide('webdriver.promise');<tr><td><a name="l50" href="#l50">50</a><td>goog.provide('webdriver.promise.ControlFlow');<tr><td><a name="l51" href="#l51">51</a><td>goog.provide('webdriver.promise.ControlFlow.Timer');<tr><td><a name="l52" href="#l52">52</a><td>goog.provide('webdriver.promise.Deferred');<tr><td><a name="l53" href="#l53">53</a><td>goog.provide('webdriver.promise.Promise');<tr><td><a name="l54" href="#l54">54</a><td>goog.provide('webdriver.promise.Thenable');<tr><td><a name="l55" href="#l55">55</a><td><tr><td><a name="l56" href="#l56">56</a><td>goog.require('goog.array');<tr><td><a name="l57" href="#l57">57</a><td>goog.require('goog.debug.Error');<tr><td><a name="l58" href="#l58">58</a><td>goog.require('goog.object');<tr><td><a name="l59" href="#l59">59</a><td>goog.require('webdriver.EventEmitter');<tr><td><a name="l60" href="#l60">60</a><td>goog.require('webdriver.stacktrace.Snapshot');<tr><td><a name="l61" href="#l61">61</a><td><tr><td><a name="l62" href="#l62">62</a><td><tr><td><a name="l63" href="#l63">63</a><td><tr><td><a name="l64" href="#l64">64</a><td>/**<tr><td><a name="l65" href="#l65">65</a><td> * Thenable is a promise-like object with a {@code then} method which may be<tr><td><a name="l66" href="#l66">66</a><td> * used to schedule callbacks on a promised value.<tr><td><a name="l67" href="#l67">67</a><td> *<tr><td><a name="l68" href="#l68">68</a><td> * @interface<tr><td><a name="l69" href="#l69">69</a><td> * @template T<tr><td><a name="l70" href="#l70">70</a><td> */<tr><td><a name="l71" href="#l71">71</a><td>webdriver.promise.Thenable = function() {};<tr><td><a name="l72" href="#l72">72</a><td><tr><td><a name="l73" href="#l73">73</a><td><tr><td><a name="l74" href="#l74">74</a><td>/**<tr><td><a name="l75" href="#l75">75</a><td> * Cancels the computation of this promise's value, rejecting the promise in the<tr><td><a name="l76" href="#l76">76</a><td> * process. This method is a no-op if the promise has alreayd been resolved.<tr><td><a name="l77" href="#l77">77</a><td> *<tr><td><a name="l78" href="#l78">78</a><td> * @param {*=} opt_reason The reason this promise is being cancelled. If not an<tr><td><a name="l79" href="#l79">79</a><td> * {@code Error}, one will be created using the value's string<tr><td><a name="l80" href="#l80">80</a><td> * representation.<tr><td><a name="l81" href="#l81">81</a><td> */<tr><td><a name="l82" href="#l82">82</a><td>webdriver.promise.Thenable.prototype.cancel = function(opt_reason) {};<tr><td><a name="l83" href="#l83">83</a><td><tr><td><a name="l84" href="#l84">84</a><td><tr><td><a name="l85" href="#l85">85</a><td>/** @return {boolean} Whether this promise's value is still being computed. */<tr><td><a name="l86" href="#l86">86</a><td>webdriver.promise.Thenable.prototype.isPending = function() {};<tr><td><a name="l87" href="#l87">87</a><td><tr><td><a name="l88" href="#l88">88</a><td><tr><td><a name="l89" href="#l89">89</a><td>/**<tr><td><a name="l90" href="#l90">90</a><td> * Registers listeners for when this instance is resolved.<tr><td><a name="l91" href="#l91">91</a><td> *<tr><td><a name="l92" href="#l92">92</a><td> * @param {?(function(T): (R|webdriver.promise.Promise.<R>))=} opt_callback The<tr><td><a name="l93" href="#l93">93</a><td> * function to call if this promise is successfully resolved. The function<tr><td><a name="l94" href="#l94">94</a><td> * should expect a single argument: the promise's resolved value.<tr><td><a name="l95" href="#l95">95</a><td> * @param {?(function(*): (R|webdriver.promise.Promise.<R>))=} opt_errback The<tr><td><a name="l96" href="#l96">96</a><td> * function to call if this promise is rejected. The function should expect<tr><td><a name="l97" href="#l97">97</a><td> * a single argument: the rejection reason.<tr><td><a name="l98" href="#l98">98</a><td> * @return {!webdriver.promise.Promise.<R>} A new promise which will be<tr><td><a name="l99" href="#l99">99</a><td> * resolved with the result of the invoked callback.<tr><td><a name="l100" href="#l100">100</a><td> * @template R<tr><td><a name="l101" href="#l101">101</a><td> */<tr><td><a name="l102" href="#l102">102</a><td>webdriver.promise.Thenable.prototype.then = function(<tr><td><a name="l103" href="#l103">103</a><td> opt_callback, opt_errback) {};<tr><td><a name="l104" href="#l104">104</a><td><tr><td><a name="l105" href="#l105">105</a><td><tr><td><a name="l106" href="#l106">106</a><td>/**<tr><td><a name="l107" href="#l107">107</a><td> * Registers a listener for when this promise is rejected. This is synonymous<tr><td><a name="l108" href="#l108">108</a><td> * with the {@code catch} clause in a synchronous API:<tr><td><a name="l109" href="#l109">109</a><td> * <pre><code><tr><td><a name="l110" href="#l110">110</a><td> * // Synchronous API:<tr><td><a name="l111" href="#l111">111</a><td> * try {<tr><td><a name="l112" href="#l112">112</a><td> * doSynchronousWork();<tr><td><a name="l113" href="#l113">113</a><td> * } catch (ex) {<tr><td><a name="l114" href="#l114">114</a><td> * console.error(ex);<tr><td><a name="l115" href="#l115">115</a><td> * }<tr><td><a name="l116" href="#l116">116</a><td> *<tr><td><a name="l117" href="#l117">117</a><td> * // Asynchronous promise API:<tr><td><a name="l118" href="#l118">118</a><td> * doAsynchronousWork().thenCatch(function(ex) {<tr><td><a name="l119" href="#l119">119</a><td> * console.error(ex);<tr><td><a name="l120" href="#l120">120</a><td> * });<tr><td><a name="l121" href="#l121">121</a><td> * </code></pre><tr><td><a name="l122" href="#l122">122</a><td> *<tr><td><a name="l123" href="#l123">123</a><td> * @param {function(*): (R|webdriver.promise.Promise.<R>)} errback The function<tr><td><a name="l124" href="#l124">124</a><td> * to call if this promise is rejected. The function should expect a single<tr><td><a name="l125" href="#l125">125</a><td> * argument: the rejection reason.<tr><td><a name="l126" href="#l126">126</a><td> * @return {!webdriver.promise.Promise.<R>} A new promise which will be<tr><td><a name="l127" href="#l127">127</a><td> * resolved with the result of the invoked callback.<tr><td><a name="l128" href="#l128">128</a><td> * @template R<tr><td><a name="l129" href="#l129">129</a><td> */<tr><td><a name="l130" href="#l130">130</a><td>webdriver.promise.Thenable.prototype.thenCatch = function(errback) {};<tr><td><a name="l131" href="#l131">131</a><td><tr><td><a name="l132" href="#l132">132</a><td><tr><td><a name="l133" href="#l133">133</a><td>/**<tr><td><a name="l134" href="#l134">134</a><td> * Registers a listener to invoke when this promise is resolved, regardless<tr><td><a name="l135" href="#l135">135</a><td> * of whether the promise's value was successfully computed. This function<tr><td><a name="l136" href="#l136">136</a><td> * is synonymous with the {@code finally} clause in a synchronous API:<tr><td><a name="l137" href="#l137">137</a><td> * <pre><code><tr><td><a name="l138" href="#l138">138</a><td> * // Synchronous API:<tr><td><a name="l139" href="#l139">139</a><td> * try {<tr><td><a name="l140" href="#l140">140</a><td> * doSynchronousWork();<tr><td><a name="l141" href="#l141">141</a><td> * } finally {<tr><td><a name="l142" href="#l142">142</a><td> * cleanUp();<tr><td><a name="l143" href="#l143">143</a><td> * }<tr><td><a name="l144" href="#l144">144</a><td> *<tr><td><a name="l145" href="#l145">145</a><td> * // Asynchronous promise API:<tr><td><a name="l146" href="#l146">146</a><td> * doAsynchronousWork().thenFinally(cleanUp);<tr><td><a name="l147" href="#l147">147</a><td> * </code></pre><tr><td><a name="l148" href="#l148">148</a><td> *<tr><td><a name="l149" href="#l149">149</a><td> * <b>Note:</b> similar to the {@code finally} clause, if the registered<tr><td><a name="l150" href="#l150">150</a><td> * callback returns a rejected promise or throws an error, it will silently<tr><td><a name="l151" href="#l151">151</a><td> * replace the rejection error (if any) from this promise:<tr><td><a name="l152" href="#l152">152</a><td> * <pre><code><tr><td><a name="l153" href="#l153">153</a><td> * try {<tr><td><a name="l154" href="#l154">154</a><td> * throw Error('one');<tr><td><a name="l155" href="#l155">155</a><td> * } finally {<tr><td><a name="l156" href="#l156">156</a><td> * throw Error('two'); // Hides Error: one<tr><td><a name="l157" href="#l157">157</a><td> * }<tr><td><a name="l158" href="#l158">158</a><td> *<tr><td><a name="l159" href="#l159">159</a><td> * webdriver.promise.rejected(Error('one'))<tr><td><a name="l160" href="#l160">160</a><td> * .thenFinally(function() {<tr><td><a name="l161" href="#l161">161</a><td> * throw Error('two'); // Hides Error: one<tr><td><a name="l162" href="#l162">162</a><td> * });<tr><td><a name="l163" href="#l163">163</a><td> * </code></pre><tr><td><a name="l164" href="#l164">164</a><td> *<tr><td><a name="l165" href="#l165">165</a><td> *<tr><td><a name="l166" href="#l166">166</a><td> * @param {function(): (R|webdriver.promise.Promise.<R>)} callback The function<tr><td><a name="l167" href="#l167">167</a><td> * to call when this promise is resolved.<tr><td><a name="l168" href="#l168">168</a><td> * @return {!webdriver.promise.Promise.<R>} A promise that will be fulfilled<tr><td><a name="l169" href="#l169">169</a><td> * with the callback result.<tr><td><a name="l170" href="#l170">170</a><td> * @template R<tr><td><a name="l171" href="#l171">171</a><td> */<tr><td><a name="l172" href="#l172">172</a><td>webdriver.promise.Thenable.prototype.thenFinally = function(callback) {};<tr><td><a name="l173" href="#l173">173</a><td><tr><td><a name="l174" href="#l174">174</a><td><tr><td><a name="l175" href="#l175">175</a><td>/**<tr><td><a name="l176" href="#l176">176</a><td> * Property used to flag constructor's as implementing the Thenable interface<tr><td><a name="l177" href="#l177">177</a><td> * for runtime type checking.<tr><td><a name="l178" href="#l178">178</a><td> * @private {string}<tr><td><a name="l179" href="#l179">179</a><td> * @const<tr><td><a name="l180" href="#l180">180</a><td> */<tr><td><a name="l181" href="#l181">181</a><td>webdriver.promise.Thenable.IMPLEMENTED_BY_PROP_ = '$webdriver_Thenable';<tr><td><a name="l182" href="#l182">182</a><td><tr><td><a name="l183" href="#l183">183</a><td><tr><td><a name="l184" href="#l184">184</a><td>/**<tr><td><a name="l185" href="#l185">185</a><td> * Adds a property to a class prototype to allow runtime checks of whether<tr><td><a name="l186" href="#l186">186</a><td> * instances of that class implement the Thenable interface. This function will<tr><td><a name="l187" href="#l187">187</a><td> * also ensure the prototype's {@code then} function is exported from compiled<tr><td><a name="l188" href="#l188">188</a><td> * code.<tr><td><a name="l189" href="#l189">189</a><td> * @param {function(new: webdriver.promise.Thenable, ...[?])} ctor The<tr><td><a name="l190" href="#l190">190</a><td> * constructor whose prototype to modify.<tr><td><a name="l191" href="#l191">191</a><td> */<tr><td><a name="l192" href="#l192">192</a><td>webdriver.promise.Thenable.addImplementation = function(ctor) {<tr><td><a name="l193" href="#l193">193</a><td> // Based on goog.promise.Thenable.isImplementation.<tr><td><a name="l194" href="#l194">194</a><td> ctor.prototype['then'] = ctor.prototype.then;<tr><td><a name="l195" href="#l195">195</a><td> try {<tr><td><a name="l196" href="#l196">196</a><td> // Old IE7 does not support defineProperty; IE8 only supports it for<tr><td><a name="l197" href="#l197">197</a><td> // DOM elements.<tr><td><a name="l198" href="#l198">198</a><td> Object.defineProperty(<tr><td><a name="l199" href="#l199">199</a><td> ctor.prototype,<tr><td><a name="l200" href="#l200">200</a><td> webdriver.promise.Thenable.IMPLEMENTED_BY_PROP_,<tr><td><a name="l201" href="#l201">201</a><td> {'value': true, 'enumerable': false});<tr><td><a name="l202" href="#l202">202</a><td> } catch (ex) {<tr><td><a name="l203" href="#l203">203</a><td> ctor.prototype[webdriver.promise.Thenable.IMPLEMENTED_BY_PROP_] = true;<tr><td><a name="l204" href="#l204">204</a><td> }<tr><td><a name="l205" href="#l205">205</a><td>};<tr><td><a name="l206" href="#l206">206</a><td><tr><td><a name="l207" href="#l207">207</a><td><tr><td><a name="l208" href="#l208">208</a><td>/**<tr><td><a name="l209" href="#l209">209</a><td> * Checks if an object has been tagged for implementing the Thenable interface<tr><td><a name="l210" href="#l210">210</a><td> * as defined by {@link webdriver.promise.Thenable.addImplementation}.<tr><td><a name="l211" href="#l211">211</a><td> * @param {*} object The object to test.<tr><td><a name="l212" href="#l212">212</a><td> * @return {boolean} Whether the object is an implementation of the Thenable<tr><td><a name="l213" href="#l213">213</a><td> * interface.<tr><td><a name="l214" href="#l214">214</a><td> */<tr><td><a name="l215" href="#l215">215</a><td>webdriver.promise.Thenable.isImplementation = function(object) {<tr><td><a name="l216" href="#l216">216</a><td> // Based on goog.promise.Thenable.isImplementation.<tr><td><a name="l217" href="#l217">217</a><td> if (!object) {<tr><td><a name="l218" href="#l218">218</a><td> return false;<tr><td><a name="l219" href="#l219">219</a><td> }<tr><td><a name="l220" href="#l220">220</a><td> try {<tr><td><a name="l221" href="#l221">221</a><td> return !!object[webdriver.promise.Thenable.IMPLEMENTED_BY_PROP_];<tr><td><a name="l222" href="#l222">222</a><td> } catch (e) {<tr><td><a name="l223" href="#l223">223</a><td> return false; // Property access seems to be forbidden.<tr><td><a name="l224" href="#l224">224</a><td> }<tr><td><a name="l225" href="#l225">225</a><td>};<tr><td><a name="l226" href="#l226">226</a><td><tr><td><a name="l227" href="#l227">227</a><td><tr><td><a name="l228" href="#l228">228</a><td><tr><td><a name="l229" href="#l229">229</a><td>/**<tr><td><a name="l230" href="#l230">230</a><td> * Represents the eventual value of a completed operation. Each promise may be<tr><td><a name="l231" href="#l231">231</a><td> * in one of three states: pending, resolved, or rejected. Each promise starts<tr><td><a name="l232" href="#l232">232</a><td> * in the pending state and may make a single transition to either a<tr><td><a name="l233" href="#l233">233</a><td> * fulfilled or rejected state, at which point the promise is considered<tr><td><a name="l234" href="#l234">234</a><td> * resolved.<tr><td><a name="l235" href="#l235">235</a><td> *<tr><td><a name="l236" href="#l236">236</a><td> * @constructor<tr><td><a name="l237" href="#l237">237</a><td> * @implements {webdriver.promise.Thenable.<T>}<tr><td><a name="l238" href="#l238">238</a><td> * @template T<tr><td><a name="l239" href="#l239">239</a><td> * @see http://promises-aplus.github.io/promises-spec/<tr><td><a name="l240" href="#l240">240</a><td> */<tr><td><a name="l241" href="#l241">241</a><td>webdriver.promise.Promise = function() {};<tr><td><a name="l242" href="#l242">242</a><td>webdriver.promise.Thenable.addImplementation(webdriver.promise.Promise);<tr><td><a name="l243" href="#l243">243</a><td><tr><td><a name="l244" href="#l244">244</a><td><tr><td><a name="l245" href="#l245">245</a><td>/** @override */<tr><td><a name="l246" href="#l246">246</a><td>webdriver.promise.Promise.prototype.cancel = function(reason) {<tr><td><a name="l247" href="#l247">247</a><td> throw new TypeError('Unimplemented function: "cancel"');<tr><td><a name="l248" href="#l248">248</a><td>};<tr><td><a name="l249" href="#l249">249</a><td><tr><td><a name="l250" href="#l250">250</a><td><tr><td><a name="l251" href="#l251">251</a><td>/** @override */<tr><td><a name="l252" href="#l252">252</a><td>webdriver.promise.Promise.prototype.isPending = function() {<tr><td><a name="l253" href="#l253">253</a><td> throw new TypeError('Unimplemented function: "isPending"');<tr><td><a name="l254" href="#l254">254</a><td>};<tr><td><a name="l255" href="#l255">255</a><td><tr><td><a name="l256" href="#l256">256</a><td><tr><td><a name="l257" href="#l257">257</a><td>/** @override */<tr><td><a name="l258" href="#l258">258</a><td>webdriver.promise.Promise.prototype.then = function(<tr><td><a name="l259" href="#l259">259</a><td> opt_callback, opt_errback) {<tr><td><a name="l260" href="#l260">260</a><td> throw new TypeError('Unimplemented function: "then"');<tr><td><a name="l261" href="#l261">261</a><td>};<tr><td><a name="l262" href="#l262">262</a><td><tr><td><a name="l263" href="#l263">263</a><td><tr><td><a name="l264" href="#l264">264</a><td>/** @override */<tr><td><a name="l265" href="#l265">265</a><td>webdriver.promise.Promise.prototype.thenCatch = function(errback) {<tr><td><a name="l266" href="#l266">266</a><td> return this.then(null, errback);<tr><td><a name="l267" href="#l267">267</a><td>};<tr><td><a name="l268" href="#l268">268</a><td><tr><td><a name="l269" href="#l269">269</a><td><tr><td><a name="l270" href="#l270">270</a><td>/** @override */<tr><td><a name="l271" href="#l271">271</a><td>webdriver.promise.Promise.prototype.thenFinally = function(callback) {<tr><td><a name="l272" href="#l272">272</a><td> return this.then(callback, function(err) {<tr><td><a name="l273" href="#l273">273</a><td> var value = callback();<tr><td><a name="l274" href="#l274">274</a><td> if (webdriver.promise.isPromise(value)) {<tr><td><a name="l275" href="#l275">275</a><td> return value.then(function() {<tr><td><a name="l276" href="#l276">276</a><td> throw err;<tr><td><a name="l277" href="#l277">277</a><td> });<tr><td><a name="l278" href="#l278">278</a><td> }<tr><td><a name="l279" href="#l279">279</a><td> throw err;<tr><td><a name="l280" href="#l280">280</a><td> });<tr><td><a name="l281" href="#l281">281</a><td>};<tr><td><a name="l282" href="#l282">282</a><td><tr><td><a name="l283" href="#l283">283</a><td><tr><td><a name="l284" href="#l284">284</a><td><tr><td><a name="l285" href="#l285">285</a><td>/**<tr><td><a name="l286" href="#l286">286</a><td> * Represents a value that will be resolved at some point in the future. This<tr><td><a name="l287" href="#l287">287</a><td> * class represents the protected "producer" half of a Promise - each Deferred<tr><td><a name="l288" href="#l288">288</a><td> * has a {@code promise} property that may be returned to consumers for<tr><td><a name="l289" href="#l289">289</a><td> * registering callbacks, reserving the ability to resolve the deferred to the<tr><td><a name="l290" href="#l290">290</a><td> * producer.<tr><td><a name="l291" href="#l291">291</a><td> *<tr><td><a name="l292" href="#l292">292</a><td> * <p>If this Deferred is rejected and there are no listeners registered before<tr><td><a name="l293" href="#l293">293</a><td> * the next turn of the event loop, the rejection will be passed to the<tr><td><a name="l294" href="#l294">294</a><td> * {@link webdriver.promise.ControlFlow} as an unhandled failure.<tr><td><a name="l295" href="#l295">295</a><td> *<tr><td><a name="l296" href="#l296">296</a><td> * <p>If this Deferred is cancelled, the cancellation reason will be forward to<tr><td><a name="l297" href="#l297">297</a><td> * the Deferred's canceller function (if provided). The canceller may return a<tr><td><a name="l298" href="#l298">298</a><td> * truth-y value to override the reason provided for rejection.<tr><td><a name="l299" href="#l299">299</a><td> *<tr><td><a name="l300" href="#l300">300</a><td> * @param {Function=} opt_canceller Function to call when cancelling the<tr><td><a name="l301" href="#l301">301</a><td> * computation of this instance's value.<tr><td><a name="l302" href="#l302">302</a><td> * @param {webdriver.promise.ControlFlow=} opt_flow The control flow<tr><td><a name="l303" href="#l303">303</a><td> * this instance was created under. This should only be provided during<tr><td><a name="l304" href="#l304">304</a><td> * unit tests.<tr><td><a name="l305" href="#l305">305</a><td> * @constructor<tr><td><a name="l306" href="#l306">306</a><td> * @extends {webdriver.promise.Promise.<T>}<tr><td><a name="l307" href="#l307">307</a><td> * @template T<tr><td><a name="l308" href="#l308">308</a><td> */<tr><td><a name="l309" href="#l309">309</a><td>webdriver.promise.Deferred = function(opt_canceller, opt_flow) {<tr><td><a name="l310" href="#l310">310</a><td> /* NOTE: This class's implementation diverges from the prototypical style<tr><td><a name="l311" href="#l311">311</a><td> * used in the rest of the atoms library. This was done intentionally to<tr><td><a name="l312" href="#l312">312</a><td> * protect the internal Deferred state from consumers, as outlined by<tr><td><a name="l313" href="#l313">313</a><td> * http://wiki.commonjs.org/wiki/Promises<tr><td><a name="l314" href="#l314">314</a><td> */<tr><td><a name="l315" href="#l315">315</a><td> goog.base(this);<tr><td><a name="l316" href="#l316">316</a><td><tr><td><a name="l317" href="#l317">317</a><td> var flow = opt_flow || webdriver.promise.controlFlow();<tr><td><a name="l318" href="#l318">318</a><td><tr><td><a name="l319" href="#l319">319</a><td> /**<tr><td><a name="l320" href="#l320">320</a><td> * The listeners registered with this Deferred. Each element in the list will<tr><td><a name="l321" href="#l321">321</a><td> * be a 3-tuple of the callback function, errback function, and the<tr><td><a name="l322" href="#l322">322</a><td> * corresponding deferred object.<tr><td><a name="l323" href="#l323">323</a><td> * @type {!Array.<!webdriver.promise.Deferred.Listener_>}<tr><td><a name="l324" href="#l324">324</a><td> */<tr><td><a name="l325" href="#l325">325</a><td> var listeners = [];<tr><td><a name="l326" href="#l326">326</a><td><tr><td><a name="l327" href="#l327">327</a><td> /**<tr><td><a name="l328" href="#l328">328</a><td> * Whether this Deferred's resolution was ever handled by a listener.<tr><td><a name="l329" href="#l329">329</a><td> * If the Deferred is rejected and its value is not handled by a listener<tr><td><a name="l330" href="#l330">330</a><td> * before the next turn of the event loop, the error will be passed to the<tr><td><a name="l331" href="#l331">331</a><td> * global error handler.<tr><td><a name="l332" href="#l332">332</a><td> * @type {boolean}<tr><td><a name="l333" href="#l333">333</a><td> */<tr><td><a name="l334" href="#l334">334</a><td> var handled = false;<tr><td><a name="l335" href="#l335">335</a><td><tr><td><a name="l336" href="#l336">336</a><td> /**<tr><td><a name="l337" href="#l337">337</a><td> * Key for the timeout used to delay reproting an unhandled rejection to the<tr><td><a name="l338" href="#l338">338</a><td> * parent {@link webdriver.promise.ControlFlow}.<tr><td><a name="l339" href="#l339">339</a><td> * @type {?number}<tr><td><a name="l340" href="#l340">340</a><td> */<tr><td><a name="l341" href="#l341">341</a><td> var pendingRejectionKey = null;<tr><td><a name="l342" href="#l342">342</a><td><tr><td><a name="l343" href="#l343">343</a><td> /**<tr><td><a name="l344" href="#l344">344</a><td> * This Deferred's current state.<tr><td><a name="l345" href="#l345">345</a><td> * @type {!webdriver.promise.Deferred.State_}<tr><td><a name="l346" href="#l346">346</a><td> */<tr><td><a name="l347" href="#l347">347</a><td> var state = webdriver.promise.Deferred.State_.PENDING;<tr><td><a name="l348" href="#l348">348</a><td><tr><td><a name="l349" href="#l349">349</a><td> /**<tr><td><a name="l350" href="#l350">350</a><td> * This Deferred's resolved value; set when the state transitions from<tr><td><a name="l351" href="#l351">351</a><td> * {@code webdriver.promise.Deferred.State_.PENDING}.<tr><td><a name="l352" href="#l352">352</a><td> * @type {*}<tr><td><a name="l353" href="#l353">353</a><td> */<tr><td><a name="l354" href="#l354">354</a><td> var value;<tr><td><a name="l355" href="#l355">355</a><td><tr><td><a name="l356" href="#l356">356</a><td> /** @return {boolean} Whether this promise's value is still pending. */<tr><td><a name="l357" href="#l357">357</a><td> function isPending() {<tr><td><a name="l358" href="#l358">358</a><td> return state == webdriver.promise.Deferred.State_.PENDING;<tr><td><a name="l359" href="#l359">359</a><td> }<tr><td><a name="l360" href="#l360">360</a><td><tr><td><a name="l361" href="#l361">361</a><td> /**<tr><td><a name="l362" href="#l362">362</a><td> * Removes all of the listeners previously registered on this deferred.<tr><td><a name="l363" href="#l363">363</a><td> * @throws {Error} If this deferred has already been resolved.<tr><td><a name="l364" href="#l364">364</a><td> */<tr><td><a name="l365" href="#l365">365</a><td> function removeAll() {<tr><td><a name="l366" href="#l366">366</a><td> listeners = [];<tr><td><a name="l367" href="#l367">367</a><td> }<tr><td><a name="l368" href="#l368">368</a><td><tr><td><a name="l369" href="#l369">369</a><td> /**<tr><td><a name="l370" href="#l370">370</a><td> * Resolves this deferred. If the new value is a promise, this function will<tr><td><a name="l371" href="#l371">371</a><td> * wait for it to be resolved before notifying the registered listeners.<tr><td><a name="l372" href="#l372">372</a><td> * @param {!webdriver.promise.Deferred.State_} newState The deferred's new<tr><td><a name="l373" href="#l373">373</a><td> * state.<tr><td><a name="l374" href="#l374">374</a><td> * @param {*} newValue The deferred's new value.<tr><td><a name="l375" href="#l375">375</a><td> */<tr><td><a name="l376" href="#l376">376</a><td> function resolve(newState, newValue) {<tr><td><a name="l377" href="#l377">377</a><td> if (webdriver.promise.Deferred.State_.PENDING !== state) {<tr><td><a name="l378" href="#l378">378</a><td> return;<tr><td><a name="l379" href="#l379">379</a><td> }<tr><td><a name="l380" href="#l380">380</a><td><tr><td><a name="l381" href="#l381">381</a><td> if (newValue === self) {<tr><td><a name="l382" href="#l382">382</a><td> // See promise a+, 2.3.1<tr><td><a name="l383" href="#l383">383</a><td> // http://promises-aplus.github.io/promises-spec/#point-48<tr><td><a name="l384" href="#l384">384</a><td> throw TypeError('A promise may not resolve to itself');<tr><td><a name="l385" href="#l385">385</a><td> }<tr><td><a name="l386" href="#l386">386</a><td><tr><td><a name="l387" href="#l387">387</a><td> state = webdriver.promise.Deferred.State_.BLOCKED;<tr><td><a name="l388" href="#l388">388</a><td><tr><td><a name="l389" href="#l389">389</a><td> if (webdriver.promise.isPromise(newValue)) {<tr><td><a name="l390" href="#l390">390</a><td> var onFulfill = goog.partial(notifyAll, newState);<tr><td><a name="l391" href="#l391">391</a><td> var onReject = goog.partial(<tr><td><a name="l392" href="#l392">392</a><td> notifyAll, webdriver.promise.Deferred.State_.REJECTED);<tr><td><a name="l393" href="#l393">393</a><td> if (newValue instanceof webdriver.promise.Deferred) {<tr><td><a name="l394" href="#l394">394</a><td> newValue.then(onFulfill, onReject);<tr><td><a name="l395" href="#l395">395</a><td> } else {<tr><td><a name="l396" href="#l396">396</a><td> webdriver.promise.asap(newValue, onFulfill, onReject);<tr><td><a name="l397" href="#l397">397</a><td> }<tr><td><a name="l398" href="#l398">398</a><td><tr><td><a name="l399" href="#l399">399</a><td> } else {<tr><td><a name="l400" href="#l400">400</a><td> notifyAll(newState, newValue);<tr><td><a name="l401" href="#l401">401</a><td> }<tr><td><a name="l402" href="#l402">402</a><td> }<tr><td><a name="l403" href="#l403">403</a><td><tr><td><a name="l404" href="#l404">404</a><td> /**<tr><td><a name="l405" href="#l405">405</a><td> * Notifies all of the listeners registered with this Deferred that its state<tr><td><a name="l406" href="#l406">406</a><td> * has changed.<tr><td><a name="l407" href="#l407">407</a><td> * @param {!webdriver.promise.Deferred.State_} newState The deferred's new<tr><td><a name="l408" href="#l408">408</a><td> * state.<tr><td><a name="l409" href="#l409">409</a><td> * @param {*} newValue The deferred's new value.<tr><td><a name="l410" href="#l410">410</a><td> */<tr><td><a name="l411" href="#l411">411</a><td> function notifyAll(newState, newValue) {<tr><td><a name="l412" href="#l412">412</a><td> if (newState === webdriver.promise.Deferred.State_.REJECTED &&<tr><td><a name="l413" href="#l413">413</a><td> // We cannot check instanceof Error since the object may have been<tr><td><a name="l414" href="#l414">414</a><td> // created in a different JS context.<tr><td><a name="l415" href="#l415">415</a><td> goog.isObject(newValue) && goog.isString(newValue.message)) {<tr><td><a name="l416" href="#l416">416</a><td> newValue = flow.annotateError(/** @type {!Error} */(newValue));<tr><td><a name="l417" href="#l417">417</a><td> }<tr><td><a name="l418" href="#l418">418</a><td><tr><td><a name="l419" href="#l419">419</a><td> state = newState;<tr><td><a name="l420" href="#l420">420</a><td> value = newValue;<tr><td><a name="l421" href="#l421">421</a><td> while (listeners.length) {<tr><td><a name="l422" href="#l422">422</a><td> notify(listeners.shift());<tr><td><a name="l423" href="#l423">423</a><td> }<tr><td><a name="l424" href="#l424">424</a><td><tr><td><a name="l425" href="#l425">425</a><td> if (!handled && state == webdriver.promise.Deferred.State_.REJECTED) {<tr><td><a name="l426" href="#l426">426</a><td> flow.pendingRejections_ += 1;<tr><td><a name="l427" href="#l427">427</a><td> pendingRejectionKey = flow.timer.setTimeout(function() {<tr><td><a name="l428" href="#l428">428</a><td> pendingRejectionKey = null;<tr><td><a name="l429" href="#l429">429</a><td> flow.pendingRejections_ -= 1;<tr><td><a name="l430" href="#l430">430</a><td> flow.abortFrame_(value);<tr><td><a name="l431" href="#l431">431</a><td> }, 0);<tr><td><a name="l432" href="#l432">432</a><td> }<tr><td><a name="l433" href="#l433">433</a><td> }<tr><td><a name="l434" href="#l434">434</a><td><tr><td><a name="l435" href="#l435">435</a><td> /**<tr><td><a name="l436" href="#l436">436</a><td> * Notifies a single listener of this Deferred's change in state.<tr><td><a name="l437" href="#l437">437</a><td> * @param {!webdriver.promise.Deferred.Listener_} listener The listener to<tr><td><a name="l438" href="#l438">438</a><td> * notify.<tr><td><a name="l439" href="#l439">439</a><td> */<tr><td><a name="l440" href="#l440">440</a><td> function notify(listener) {<tr><td><a name="l441" href="#l441">441</a><td> var func = state == webdriver.promise.Deferred.State_.RESOLVED ?<tr><td><a name="l442" href="#l442">442</a><td> listener.callback : listener.errback;<tr><td><a name="l443" href="#l443">443</a><td> if (func) {<tr><td><a name="l444" href="#l444">444</a><td> flow.runInNewFrame_(goog.partial(func, value),<tr><td><a name="l445" href="#l445">445</a><td> listener.fulfill, listener.reject);<tr><td><a name="l446" href="#l446">446</a><td> } else if (state == webdriver.promise.Deferred.State_.REJECTED) {<tr><td><a name="l447" href="#l447">447</a><td> listener.reject(value);<tr><td><a name="l448" href="#l448">448</a><td> } else {<tr><td><a name="l449" href="#l449">449</a><td> listener.fulfill(value);<tr><td><a name="l450" href="#l450">450</a><td> }<tr><td><a name="l451" href="#l451">451</a><td> }<tr><td><a name="l452" href="#l452">452</a><td><tr><td><a name="l453" href="#l453">453</a><td> /**<tr><td><a name="l454" href="#l454">454</a><td> * The consumer promise for this instance. Provides protected access to the<tr><td><a name="l455" href="#l455">455</a><td> * callback registering functions.<tr><td><a name="l456" href="#l456">456</a><td> * @type {!webdriver.promise.Promise.<T>}<tr><td><a name="l457" href="#l457">457</a><td> */<tr><td><a name="l458" href="#l458">458</a><td> var promise = new webdriver.promise.Promise();<tr><td><a name="l459" href="#l459">459</a><td><tr><td><a name="l460" href="#l460">460</a><td> /**<tr><td><a name="l461" href="#l461">461</a><td> * Registers a callback on this Deferred.<tr><td><a name="l462" href="#l462">462</a><td> *<tr><td><a name="l463" href="#l463">463</a><td> * @param {?(function(T): (R|webdriver.promise.Promise.<R>))=} opt_callback .<tr><td><a name="l464" href="#l464">464</a><td> * @param {?(function(*): (R|webdriver.promise.Promise.<R>))=} opt_errback .<tr><td><a name="l465" href="#l465">465</a><td> * @return {!webdriver.promise.Promise.<R>} A new promise representing the<tr><td><a name="l466" href="#l466">466</a><td> * result of the callback.<tr><td><a name="l467" href="#l467">467</a><td> * @template R<tr><td><a name="l468" href="#l468">468</a><td> * @see webdriver.promise.Promise#then<tr><td><a name="l469" href="#l469">469</a><td> */<tr><td><a name="l470" href="#l470">470</a><td> function then(opt_callback, opt_errback) {<tr><td><a name="l471" href="#l471">471</a><td> // Avoid unnecessary allocations if we weren't given any callback functions.<tr><td><a name="l472" href="#l472">472</a><td> if (!opt_callback && !opt_errback) {<tr><td><a name="l473" href="#l473">473</a><td> return promise;<tr><td><a name="l474" href="#l474">474</a><td> }<tr><td><a name="l475" href="#l475">475</a><td><tr><td><a name="l476" href="#l476">476</a><td> // The moment a listener is registered, we consider this deferred to be<tr><td><a name="l477" href="#l477">477</a><td> // handled; the callback must handle any rejection errors.<tr><td><a name="l478" href="#l478">478</a><td> handled = true;<tr><td><a name="l479" href="#l479">479</a><td> if (pendingRejectionKey !== null) {<tr><td><a name="l480" href="#l480">480</a><td> flow.pendingRejections_ -= 1;<tr><td><a name="l481" href="#l481">481</a><td> flow.timer.clearTimeout(pendingRejectionKey);<tr><td><a name="l482" href="#l482">482</a><td> pendingRejectionKey = null;<tr><td><a name="l483" href="#l483">483</a><td> }<tr><td><a name="l484" href="#l484">484</a><td><tr><td><a name="l485" href="#l485">485</a><td> var deferred = new webdriver.promise.Deferred(cancel, flow);<tr><td><a name="l486" href="#l486">486</a><td> var listener = {<tr><td><a name="l487" href="#l487">487</a><td> callback: opt_callback,<tr><td><a name="l488" href="#l488">488</a><td> errback: opt_errback,<tr><td><a name="l489" href="#l489">489</a><td> fulfill: deferred.fulfill,<tr><td><a name="l490" href="#l490">490</a><td> reject: deferred.reject<tr><td><a name="l491" href="#l491">491</a><td> };<tr><td><a name="l492" href="#l492">492</a><td><tr><td><a name="l493" href="#l493">493</a><td> if (state == webdriver.promise.Deferred.State_.PENDING ||<tr><td><a name="l494" href="#l494">494</a><td> state == webdriver.promise.Deferred.State_.BLOCKED) {<tr><td><a name="l495" href="#l495">495</a><td> listeners.push(listener);<tr><td><a name="l496" href="#l496">496</a><td> } else {<tr><td><a name="l497" href="#l497">497</a><td> notify(listener);<tr><td><a name="l498" href="#l498">498</a><td> }<tr><td><a name="l499" href="#l499">499</a><td><tr><td><a name="l500" href="#l500">500</a><td> return deferred.promise;<tr><td><a name="l501" href="#l501">501</a><td> }<tr><td><a name="l502" href="#l502">502</a><td><tr><td><a name="l503" href="#l503">503</a><td> var self = this;<tr><td><a name="l504" href="#l504">504</a><td><tr><td><a name="l505" href="#l505">505</a><td> /**<tr><td><a name="l506" href="#l506">506</a><td> * Resolves this promise with the given value. If the value is itself a<tr><td><a name="l507" href="#l507">507</a><td> * promise and not a reference to this deferred, this instance will wait for<tr><td><a name="l508" href="#l508">508</a><td> * it before resolving.<tr><td><a name="l509" href="#l509">509</a><td> * @param {T=} opt_value The fulfilled value.<tr><td><a name="l510" href="#l510">510</a><td> */<tr><td><a name="l511" href="#l511">511</a><td> function fulfill(opt_value) {<tr><td><a name="l512" href="#l512">512</a><td> resolve(webdriver.promise.Deferred.State_.RESOLVED, opt_value);<tr><td><a name="l513" href="#l513">513</a><td> }<tr><td><a name="l514" href="#l514">514</a><td><tr><td><a name="l515" href="#l515">515</a><td> /**<tr><td><a name="l516" href="#l516">516</a><td> * Rejects this promise. If the error is itself a promise, this instance will<tr><td><a name="l517" href="#l517">517</a><td> * be chained to it and be rejected with the error's resolved value.<tr><td><a name="l518" href="#l518">518</a><td> * @param {*=} opt_error The rejection reason, typically either a<tr><td><a name="l519" href="#l519">519</a><td> * {@code Error} or a {@code string}.<tr><td><a name="l520" href="#l520">520</a><td> */<tr><td><a name="l521" href="#l521">521</a><td> function reject(opt_error) {<tr><td><a name="l522" href="#l522">522</a><td> resolve(webdriver.promise.Deferred.State_.REJECTED, opt_error);<tr><td><a name="l523" href="#l523">523</a><td> }<tr><td><a name="l524" href="#l524">524</a><td><tr><td><a name="l525" href="#l525">525</a><td> /**<tr><td><a name="l526" href="#l526">526</a><td> * Attempts to cancel the computation of this instance's value. This attempt<tr><td><a name="l527" href="#l527">527</a><td> * will silently fail if this instance has already resolved.<tr><td><a name="l528" href="#l528">528</a><td> * @param {*=} opt_reason The reason for cancelling this promise.<tr><td><a name="l529" href="#l529">529</a><td> */<tr><td><a name="l530" href="#l530">530</a><td> function cancel(opt_reason) {<tr><td><a name="l531" href="#l531">531</a><td> if (!isPending()) {<tr><td><a name="l532" href="#l532">532</a><td> return;<tr><td><a name="l533" href="#l533">533</a><td> }<tr><td><a name="l534" href="#l534">534</a><td><tr><td><a name="l535" href="#l535">535</a><td> if (opt_canceller) {<tr><td><a name="l536" href="#l536">536</a><td> opt_reason = opt_canceller(opt_reason) || opt_reason;<tr><td><a name="l537" href="#l537">537</a><td> }<tr><td><a name="l538" href="#l538">538</a><td><tr><td><a name="l539" href="#l539">539</a><td> reject(opt_reason);<tr><td><a name="l540" href="#l540">540</a><td> }<tr><td><a name="l541" href="#l541">541</a><td><tr><td><a name="l542" href="#l542">542</a><td> this.promise = promise;<tr><td><a name="l543" href="#l543">543</a><td> this.promise.then = this.then = then;<tr><td><a name="l544" href="#l544">544</a><td> this.promise.cancel = this.cancel = cancel;<tr><td><a name="l545" href="#l545">545</a><td> this.promise.isPending = this.isPending = isPending;<tr><td><a name="l546" href="#l546">546</a><td> this.fulfill = fulfill;<tr><td><a name="l547" href="#l547">547</a><td> this.reject = this.errback = reject;<tr><td><a name="l548" href="#l548">548</a><td><tr><td><a name="l549" href="#l549">549</a><td> // Only expose this function to our internal classes.<tr><td><a name="l550" href="#l550">550</a><td> // TODO: find a cleaner way of handling this.<tr><td><a name="l551" href="#l551">551</a><td> if (this instanceof webdriver.promise.Task_) {<tr><td><a name="l552" href="#l552">552</a><td> this.removeAll = removeAll;<tr><td><a name="l553" href="#l553">553</a><td> }<tr><td><a name="l554" href="#l554">554</a><td><tr><td><a name="l555" href="#l555">555</a><td> // Export symbols necessary for the contract on this object to work in<tr><td><a name="l556" href="#l556">556</a><td> // compiled mode.<tr><td><a name="l557" href="#l557">557</a><td> goog.exportProperty(this, 'then', this.then);<tr><td><a name="l558" href="#l558">558</a><td> goog.exportProperty(this, 'cancel', cancel);<tr><td><a name="l559" href="#l559">559</a><td> goog.exportProperty(this, 'fulfill', fulfill);<tr><td><a name="l560" href="#l560">560</a><td> goog.exportProperty(this, 'reject', reject);<tr><td><a name="l561" href="#l561">561</a><td> goog.exportProperty(this, 'isPending', isPending);<tr><td><a name="l562" href="#l562">562</a><td> goog.exportProperty(this, 'promise', this.promise);<tr><td><a name="l563" href="#l563">563</a><td> goog.exportProperty(this.promise, 'then', this.then);<tr><td><a name="l564" href="#l564">564</a><td> goog.exportProperty(this.promise, 'cancel', cancel);<tr><td><a name="l565" href="#l565">565</a><td> goog.exportProperty(this.promise, 'isPending', isPending);<tr><td><a name="l566" href="#l566">566</a><td>};<tr><td><a name="l567" href="#l567">567</a><td>goog.inherits(webdriver.promise.Deferred, webdriver.promise.Promise);<tr><td><a name="l568" href="#l568">568</a><td><tr><td><a name="l569" href="#l569">569</a><td><tr><td><a name="l570" href="#l570">570</a><td>/**<tr><td><a name="l571" href="#l571">571</a><td> * Type definition for a listener registered on a Deferred object.<tr><td><a name="l572" href="#l572">572</a><td> * @typedef {{callback:(Function|undefined),<tr><td><a name="l573" href="#l573">573</a><td> * errback:(Function|undefined),<tr><td><a name="l574" href="#l574">574</a><td> * fulfill: function(*), reject: function(*)}}<tr><td><a name="l575" href="#l575">575</a><td> * @private<tr><td><a name="l576" href="#l576">576</a><td> */<tr><td><a name="l577" href="#l577">577</a><td>webdriver.promise.Deferred.Listener_;<tr><td><a name="l578" href="#l578">578</a><td><tr><td><a name="l579" href="#l579">579</a><td><tr><td><a name="l580" href="#l580">580</a><td>/**<tr><td><a name="l581" href="#l581">581</a><td> * The three states a {@link webdriver.promise.Deferred} object may be in.<tr><td><a name="l582" href="#l582">582</a><td> * @enum {number}<tr><td><a name="l583" href="#l583">583</a><td> * @private<tr><td><a name="l584" href="#l584">584</a><td> */<tr><td><a name="l585" href="#l585">585</a><td>webdriver.promise.Deferred.State_ = {<tr><td><a name="l586" href="#l586">586</a><td> REJECTED: -1,<tr><td><a name="l587" href="#l587">587</a><td> PENDING: 0,<tr><td><a name="l588" href="#l588">588</a><td> BLOCKED: 1,<tr><td><a name="l589" href="#l589">589</a><td> RESOLVED: 2<tr><td><a name="l590" href="#l590">590</a><td>};<tr><td><a name="l591" href="#l591">591</a><td><tr><td><a name="l592" href="#l592">592</a><td><tr><td><a name="l593" href="#l593">593</a><td>/**<tr><td><a name="l594" href="#l594">594</a><td> * Tests if a value is an Error-like object. This is more than an straight<tr><td><a name="l595" href="#l595">595</a><td> * instanceof check since the value may originate from another context.<tr><td><a name="l596" href="#l596">596</a><td> * @param {*} value The value to test.<tr><td><a name="l597" href="#l597">597</a><td> * @return {boolean} Whether the value is an error.<tr><td><a name="l598" href="#l598">598</a><td> * @private<tr><td><a name="l599" href="#l599">599</a><td> */<tr><td><a name="l600" href="#l600">600</a><td>webdriver.promise.isError_ = function(value) {<tr><td><a name="l601" href="#l601">601</a><td> return value instanceof Error ||<tr><td><a name="l602" href="#l602">602</a><td> goog.isObject(value) &&<tr><td><a name="l603" href="#l603">603</a><td> (Object.prototype.toString.call(value) === '[object Error]' ||<tr><td><a name="l604" href="#l604">604</a><td> // A special test for goog.testing.JsUnitException.<tr><td><a name="l605" href="#l605">605</a><td> value.isJsUnitException);<tr><td><a name="l606" href="#l606">606</a><td><tr><td><a name="l607" href="#l607">607</a><td>};<tr><td><a name="l608" href="#l608">608</a><td><tr><td><a name="l609" href="#l609">609</a><td><tr><td><a name="l610" href="#l610">610</a><td>/**<tr><td><a name="l611" href="#l611">611</a><td> * Determines whether a {@code value} should be treated as a promise.<tr><td><a name="l612" href="#l612">612</a><td> * Any object whose "then" property is a function will be considered a promise.<tr><td><a name="l613" href="#l613">613</a><td> *<tr><td><a name="l614" href="#l614">614</a><td> * @param {*} value The value to test.<tr><td><a name="l615" href="#l615">615</a><td> * @return {boolean} Whether the value is a promise.<tr><td><a name="l616" href="#l616">616</a><td> */<tr><td><a name="l617" href="#l617">617</a><td>webdriver.promise.isPromise = function(value) {<tr><td><a name="l618" href="#l618">618</a><td> return !!value && goog.isObject(value) &&<tr><td><a name="l619" href="#l619">619</a><td> // Use array notation so the Closure compiler does not obfuscate away our<tr><td><a name="l620" href="#l620">620</a><td> // contra