1<!DOCTYPE html><!-- This page is a placeholder for generated extensions api doc. Note: 2 1) The <head> information in this page is significant, should be uniform 3 across api docs and should be edited only with knowledge of the 4 templating mechanism. 5 3) All <body>.innerHTML is genereated as an rendering step. If viewed in a 6 browser, it will be re-generated from the template, json schema and 7 authored overview content. 8 4) The <body>.innerHTML is also generated by an offline step so that this 9 page may easily be indexed by search engines. 10--><html xmlns="http://www.w3.org/1999/xhtml"><head> 11 <meta http-equiv="Content-Type" content="text/html; charset=UTF-8"> 12 <link href="css/ApiRefStyles.css" rel="stylesheet" type="text/css"> 13 <link href="css/print.css" rel="stylesheet" type="text/css" media="print"> 14 <script type="text/javascript" src="/third_party/jstemplate/jstemplate_compiled.js"> 15 </script> 16 <script type="text/javascript" src="js/api_page_generator.js"></script> 17 <script type="text/javascript" src="js/bootstrap.js"></script> 18 <script type="text/javascript" src="js/sidebar.js"></script> 19 <title>Events - Google Chrome Extensions - Google Code</title></head> 20 <body> <div id="gc-container" class="labs"> 21 <div id="devModeWarning"> 22 You are viewing extension docs in chrome via the 'file:' scheme: are you expecting to see local changes when you refresh? You'll need run chrome with --allow-file-access-from-files. 23 </div> 24 <!-- SUBTEMPLATES: DO NOT MOVE FROM THIS LOCATION --> 25 <!-- In particular, sub-templates that recurse, must be used by allowing 26 jstemplate to make a copy of the template in this section which 27 are not operated on by way of the jsskip="true" --> 28 <div style="display:none"> 29 30 <!-- VALUE --> 31 <div id="valueTemplate"> 32 <dt> 33 <var>paramName</var> 34 <em> 35 36 <!-- TYPE --> 37 <div style="display:inline"> 38 ( 39 <span class="optional">optional</span> 40 <span class="enum">enumerated</span> 41 <span id="typeTemplate"> 42 <span> 43 <a> Type</a> 44 </span> 45 <span> 46 <span> 47 array of <span><span></span></span> 48 </span> 49 <span>paramType</span> 50 <span></span> 51 </span> 52 </span> 53 ) 54 </div> 55 56 </em> 57 </dt> 58 <dd class="todo"> 59 Undocumented. 60 </dd> 61 <dd> 62 Description of this parameter from the json schema. 63 </dd> 64 <dd> 65 This parameter was added in version 66 <b><span></span></b>. 67 You must omit this parameter in earlier versions, 68 and you may omit it in any version. If you require this 69 parameter, the manifest key 70 <a href="manifest.html#minimum_chrome_version">minimum_chrome_version</a> 71 can ensure that your extension won't be run in an earlier browser version. 72 </dd> 73 74 <!-- OBJECT PROPERTIES --> 75 <dd> 76 <dl> 77 <div> 78 <div> 79 </div> 80 </div> 81 </dl> 82 </dd> 83 84 <!-- OBJECT METHODS --> 85 <dd> 86 <div></div> 87 </dd> 88 89 <!-- OBJECT EVENT FIELDS --> 90 <dd> 91 <div></div> 92 </dd> 93 94 <!-- FUNCTION PARAMETERS --> 95 <dd> 96 <div></div> 97 </dd> 98 99 </div> <!-- /VALUE --> 100 101 <div id="functionParametersTemplate"> 102 <h5>Parameters</h5> 103 <dl> 104 <div> 105 <div> 106 </div> 107 </div> 108 </dl> 109 </div> 110 </div> <!-- /SUBTEMPLATES --> 111 112 <a id="top"></a> 113 <div id="skipto"> 114 <a href="#gc-pagecontent">Skip to page content</a> 115 <a href="#gc-toc">Skip to main navigation</a> 116 </div> 117 <!-- API HEADER --> 118 <table id="header" width="100%" cellspacing="0" border="0"> 119 <tbody><tr> 120 <td valign="middle"><a href="http://code.google.com/"><img src="images/code_labs_logo.gif" height="43" width="161" alt="Google Code Labs" style="border:0; margin:0;"></a></td> 121 <td valign="middle" width="100%" style="padding-left:0.6em;"> 122 <form action="http://www.google.com/cse" id="cse" style="margin-top:0.5em"> 123 <div id="gsc-search-box"> 124 <input type="hidden" name="cx" value="002967670403910741006:61_cvzfqtno"> 125 <input type="hidden" name="ie" value="UTF-8"> 126 <input type="text" name="q" value="" size="55"> 127 <input class="gsc-search-button" type="submit" name="sa" value="Search"> 128 <br> 129 <span class="greytext">e.g. "page action" or "tabs"</span> 130 </div> 131 </form> 132 133 <script type="text/javascript" src="http://www.google.com/jsapi"></script> 134 <script type="text/javascript">google.load("elements", "1", {packages: "transliteration"});</script> 135 <script type="text/javascript" src="http://www.google.com/coop/cse/t13n?form=cse&t13n_langs=en"></script> 136 <script type="text/javascript" src="http://www.google.com/coop/cse/brand?form=cse&lang=en"></script> 137 </td> 138 </tr> 139 </tbody></table> 140 141 <div id="codesiteContent" class=""> 142 143 <a id="gc-topnav-anchor"></a> 144 <div id="gc-topnav"> 145 <h1>Google Chrome Extensions (<a href="http://code.google.com/labs/">Labs</a>)</h1> 146 <ul id="home" class="gc-topnav-tabs"> 147 <li id="home_link"> 148 <a href="index.html" title="Google Chrome Extensions home page">Home</a> 149 </li> 150 <li id="docs_link"> 151 <a href="docs.html" title="Official Google Chrome Extensions documentation">Docs</a> 152 </li> 153 <li id="faq_link"> 154 <a href="faq.html" title="Answers to frequently asked questions about Google Chrome Extensions">FAQ</a> 155 </li> 156 <li id="samples_link"> 157 <a href="samples.html" title="Sample extensions (with source code)">Samples</a> 158 </li> 159 <li id="group_link"> 160 <a href="http://groups.google.com/a/chromium.org/group/chromium-extensions" title="Google Chrome Extensions developer forum">Group</a> 161 </li> 162 </ul> 163 </div> <!-- end gc-topnav --> 164 165 <div class="g-section g-tpl-170"> 166 <!-- SIDENAV --> 167 <div class="g-unit g-first" id="gc-toc"> 168 <ul> 169 <li><a href="getstarted.html">Getting Started</a></li> 170 <li><a href="overview.html">Overview</a></li> 171 <li><a href="whats_new.html">What's New?</a></li> 172 <li><h2><a href="devguide.html">Developer's Guide</a></h2> 173 <ul> 174 <li>Browser UI 175 <ul> 176 <li><a href="browserAction.html">Browser Actions</a></li> 177 <li><a href="contextMenus.html">Context Menus</a></li> 178 <li><a href="notifications.html">Desktop Notifications</a></li> 179 <li><a href="omnibox.html">Omnibox</a></li> 180 <li><a href="options.html">Options Pages</a></li> 181 <li><a href="override.html">Override Pages</a></li> 182 <li><a href="pageAction.html">Page Actions</a></li> 183 </ul> 184 </li> 185 <li>Browser Interaction 186 <ul> 187 <li><a href="bookmarks.html">Bookmarks</a></li> 188 <li><a href="cookies.html">Cookies</a></li> 189 <li class="leftNavSelected">Events</li> 190 <li><a href="history.html">History</a></li> 191 <li><a href="management.html">Management</a></li> 192 <li><a href="tabs.html">Tabs</a></li> 193 <li><a href="windows.html">Windows</a></li> 194 </ul> 195 </li> 196 <li>Implementation 197 <ul> 198 <li><a href="a11y.html">Accessibility</a></li> 199 <li><a href="background_pages.html">Background Pages</a></li> 200 <li><a href="content_scripts.html">Content Scripts</a></li> 201 <li><a href="xhr.html">Cross-Origin XHR</a></li> 202 <li><a href="idle.html">Idle</a></li> 203 <li><a href="i18n.html">Internationalization</a></li> 204 <li><a href="messaging.html">Message Passing</a></li> 205 <li><a href="npapi.html">NPAPI Plugins</a></li> 206 </ul> 207 </li> 208 <li>Finishing 209 <ul> 210 <li><a href="hosting.html">Hosting</a></li> 211 <li><a href="external_extensions.html">Other Deployment Options</a></li> 212 </ul> 213 </li> 214 </ul> 215 </li> 216 <li><h2><a href="apps.html">Packaged Apps</a></h2></li> 217 <li><h2><a href="tutorials.html">Tutorials</a></h2> 218 <ul> 219 <li><a href="tut_debugging.html">Debugging</a></li> 220 <li><a href="tut_analytics.html">Google Analytics</a></li> 221 <li><a href="tut_oauth.html">OAuth</a></li> 222 </ul> 223 </li> 224 <li><h2>Reference</h2> 225 <ul> 226 <li>Formats 227 <ul> 228 <li><a href="manifest.html">Manifest Files</a></li> 229 <li><a href="match_patterns.html">Match Patterns</a></li> 230 </ul> 231 </li> 232 <li><a href="permission_warnings.html">Permission Warnings</a></li> 233 <li><a href="api_index.html">chrome.* APIs</a></li> 234 <li><a href="api_other.html">Other APIs</a></li> 235 </ul> 236 </li> 237 <li><h2><a href="samples.html">Samples</a></h2></li> 238 <div class="line"> </div> 239 <li><h2>More</h2> 240 <ul> 241 <li><a href="http://code.google.com/chrome/webstore/docs/index.html">Chrome Web Store</a></li> 242 <li><a href="http://code.google.com/chrome/apps/docs/developers_guide.html">Hosted Apps</a></li> 243 <li><a href="themes.html">Themes</a></li> 244 </ul> 245 </li> 246 </ul> 247 </div> 248 <script> 249 initToggles(); 250 </script> 251 252 <div class="g-unit" id="gc-pagecontent"> 253 <div id="pageTitle"> 254 <h1 class="page_title">Events</h1> 255 </div> 256 <!-- TABLE OF CONTENTS --> 257 <div id="toc" style="display: none; "> 258 <h2>Contents</h2> 259 <ol> 260 <li> 261 <a>h2Name</a> 262 <ol> 263 <li> 264 <a>h3Name</a> 265 </li> 266 </ol> 267 </li> 268 <li> 269 <a href="#apiReference">API reference</a> 270 <ol> 271 <li> 272 <a href="#properties">Properties</a> 273 <ol> 274 <li> 275 <a href="#property-anchor">propertyName</a> 276 </li> 277 </ol> 278 </li> 279 <li> 280 <a>Methods</a> 281 <ol> 282 <li> 283 <a href="#method-anchor">methodName</a> 284 </li> 285 </ol> 286 </li> 287 <li> 288 <a>Events</a> 289 <ol> 290 <li> 291 <a href="#event-anchor">eventName</a> 292 </li> 293 </ol> 294 </li> 295 <li> 296 <a href="#types">Types</a> 297 <ol> 298 <li> 299 <a href="#id-anchor">id</a> 300 </li> 301 </ol> 302 </li> 303 </ol> 304 </li> 305 </ol> 306 </div> 307 <!-- /TABLE OF CONTENTS --> 308 309 <!-- Standard content lead-in for experimental API pages --> 310 <p id="classSummary" style="display: none; "> 311 For information on how to use experimental APIs, see the <a href="experimental.html">chrome.experimental.* APIs</a> page. 312 </p> 313 314 <!-- STATIC CONTENT PLACEHOLDER --> 315 <div id="static"><p> 316An <code>Event</code> is an object 317that allows you to be notified 318when something interesting happens. 319Here's an example of using the 320<code>chrome.tabs.onCreated</code> event 321to be notified whenever there's a new tab: 322</p> 323 324<pre>chrome.tabs.onCreated.<b>addListener(function(</b>tab<b>) {</b> 325 appendToLog('tabs.onCreated --' 326 + ' window: ' + tab.windowId 327 + ' tab: ' + tab.id 328 + ' index: ' + tab.index 329 + ' url: ' + tab.url); 330<b>});</b> 331</pre> 332 333<p> 334As the example shows, 335you register for notification using <code>addListener()</code>. 336The argument to <code>addListener()</code> 337is always a function that you define to handle the event, 338but the parameters to the function depend on 339which event you're handling. 340Checking the documentation for 341<a href="tabs.html#event-onCreated"><code>chrome.tabs.onCreated</code></a>, 342you can see that the function has a single parameter: 343a <a href="tabs.html#type-Tab">Tab</a> object 344that has details about the newly created tab. 345</p> 346 347<h2> 348Methods 349</h2> 350 351<p> 352You can invoke the following methods on any <code>Event</code> object: 353</p> 354 355<pre>void addListener(function callback(...)) 356void removeListener(function callback(...)) 357bool hasListener(function callback(...)) 358</pre> 359 360<!-- [PENDING: explain removeListener and hasListener] --> 361</div> 362 363 <!-- API PAGE --> 364 <div class="apiPage" style="display: none; "> 365 <a name="apiReference"></a> 366 <h2>API reference: chrome.apiname </h2> 367 368 <!-- PROPERTIES --> 369 <div class="apiGroup"> 370 <a name="properties"></a> 371 <h3 id="properties">Properties</h3> 372 373 <div> 374 <a></a> 375 <h4>getLastError</h4> 376 <div class="summary"> 377 <!-- Note: intentionally longer 80 columns --> 378 <span>chrome.extension</span><span>lastError</span> 379 </div> 380 <div> 381 </div> 382 </div> 383 384 </div> <!-- /apiGroup --> 385 386 <!-- METHODS --> 387 <div id="methodsTemplate" class="apiGroup"> 388 <a></a> 389 <h3>Methods</h3> 390 391 <!-- iterates over all functions --> 392 <div class="apiItem"> 393 <a></a> <!-- method-anchor --> 394 <h4>method name</h4> 395 396 <div class="summary"><span>void</span> 397 <!-- Note: intentionally longer 80 columns --> 398 <span>chrome.module.methodName</span>(<span><span>, </span><span></span> 399 <var><span></span></var></span>)</div> 400 401 <div class="description"> 402 <p class="todo">Undocumented.</p> 403 <p> 404 A description from the json schema def of the function goes here. 405 </p> 406 407 <!-- PARAMETERS --> 408 <h4>Parameters</h4> 409 <dl> 410 <div> 411 <div> 412 </div> 413 </div> 414 </dl> 415 416 <!-- RETURNS --> 417 <h4>Returns</h4> 418 <dl> 419 <div> 420 <div> 421 </div> 422 </div> 423 </dl> 424 425 <!-- CALLBACK --> 426 <div> 427 <div> 428 <h4>Callback function</h4> 429 <p> 430 The callback <em>parameter</em> should specify a function 431 that looks like this: 432 </p> 433 <p> 434 If you specify the <em>callback</em> parameter, it should 435 specify a function that looks like this: 436 </p> 437 438 <!-- Note: intentionally longer 80 columns --> 439 <pre>function(<span>Type param1, Type param2</span>) <span class="subdued">{...}</span>;</pre> 440 <dl> 441 <div> 442 <div> 443 </div> 444 </div> 445 </dl> 446 </div> 447 </div> 448 449 <!-- MIN_VERSION --> 450 <p> 451 This function was added in version <b><span></span></b>. 452 If you require this function, the manifest key 453 <a href="manifest.html#minimum_chrome_version">minimum_chrome_version</a> 454 can ensure that your extension won't be run in an earlier browser version. 455 </p> 456 </div> <!-- /description --> 457 458 </div> <!-- /apiItem --> 459 460 </div> <!-- /apiGroup --> 461 462 <!-- EVENTS --> 463 <div id="eventsTemplate" class="apiGroup"> 464 <a></a> 465 <h3>Events</h3> 466 <!-- iterates over all events --> 467 <div class="apiItem"> 468 <a></a> 469 <h4>event name</h4> 470 471 <div class="summary"> 472 <!-- Note: intentionally longer 80 columns --> 473 <span class="subdued">chrome.bookmarks</span><span>onEvent</span><span class="subdued">.addListener</span>(function(<span>Type param1, Type param2</span>) <span class="subdued">{...}</span>); 474 </div> 475 476 <div class="description"> 477 <p class="todo">Undocumented.</p> 478 <p> 479 A description from the json schema def of the event goes here. 480 </p> 481 482 <!-- PARAMETERS --> 483 <div> 484 <h4>Parameters</h4> 485 <dl> 486 <div> 487 <div> 488 </div> 489 </div> 490 </dl> 491 </div> 492 </div> <!-- /decription --> 493 494 </div> <!-- /apiItem --> 495 496 </div> <!-- /apiGroup --> 497 498 <!-- TYPES --> 499 <div class="apiGroup"> 500 <a name="types"></a> 501 <h3 id="types">Types</h3> 502 503 <!-- iterates over all types --> 504 <div class="apiItem"> 505 <a></a> 506 <h4>type name</h4> 507 508 <div> 509 </div> 510 511 </div> <!-- /apiItem --> 512 513 </div> <!-- /apiGroup --> 514 515 </div> <!-- /apiPage --> 516 </div> <!-- /gc-pagecontent --> 517 </div> <!-- /g-section --> 518 </div> <!-- /codesiteContent --> 519 <div id="gc-footer" --=""> 520 <div class="text"> 521 <p> 522 Except as otherwise <a href="http://code.google.com/policies.html#restrictions">noted</a>, 523 the content of this page is licensed under the <a rel="license" href="http://creativecommons.org/licenses/by/3.0/">Creative Commons 524 Attribution 3.0 License</a>, and code samples are licensed under the 525 <a rel="license" href="http://code.google.com/google_bsd_license.html">BSD License</a>. 526 </p> 527 <p> 528 ©2011 Google 529 </p> 530 531<!-- begin analytics --> 532<script src="http://www.google-analytics.com/urchin.js" type="text/javascript"></script> 533<script src="http://www.google-analytics.com/ga.js" type="text/javascript"></script> 534 535<script type="text/javascript"> 536 // chrome doc tracking 537 try { 538 var engdocs = _gat._getTracker("YT-10763712-2"); 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