| Index: chrome/common/extensions/docs/static/event_pages.html
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| diff --git a/chrome/common/extensions/docs/static/event_pages.html b/chrome/common/extensions/docs/static/event_pages.html
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| index 723f99ebd368e675f154534ba37ddf62257ed280..4956a5075eaf6a24e4b61ce1274f11380219ee46 100644
|
| --- a/chrome/common/extensions/docs/static/event_pages.html
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| +++ b/chrome/common/extensions/docs/static/event_pages.html
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| @@ -58,6 +58,14 @@ popup windows) are closed.
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| </p>
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|
|
| <p>
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| +You can observe the lifetime of your event page by clicking
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| +on "View Background Pages" in Chrome's Wrench menu, or by
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| +opening Chrome's task manager. You can see when your event
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| +page loads and unloads by observing when an entry for your
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| +extension appears in the list of processes.
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| +</p>
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| +
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| +<p>
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| Once the event page has been idle a short time
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| (a few seconds), the
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| <code><a href="runtime.html#event-onSuspend">chrome.runtime.onSuspend</a></code>
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| @@ -65,3 +73,51 @@ event is dispatched. The event page has a few more seconds to handle this
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| event before it is forcibly unloaded. Note that once the event is dispatched,
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| new activity will not keep the event page open.
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| </p>
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| +
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| +<h2 id="transition">Convert background page to event page</h2>
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| +<p>
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| +Follow this checklist to convert your extension's
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| +(persistent) background page to an event page.
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| +
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| +<ol>
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| + <li>Add <code>"persistent": false</code> to your manifest as shown above.
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| +
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| + <li>Register to receive any events your extension is interested in
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| + each time the event page is loaded. The event page will be loaded once
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| + for each new version of your extension. After that it will only be
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| + loaded to deliver events you have registered for.
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| +
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| + <li>If you need to do some initialization when your extension is
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| + installed or upgraded, listen to the
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| + <code><a href="runtime.html#event-onInstalled">chrome.runtime.onInstalled</a></code>
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| + event.
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| +
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| + <li>If you need to keep runtime state in memory throughout a browser
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| + session, use the <a href="storage.html">storage API</a> or
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| + IndexedDB. Since the event page does not stay loaded for long, you
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| + can no longer rely on global variables for runtime state.
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| +
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| + <li>Listen to the
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| + <code><a href="runtime.html#event-onSuspend">chrome.runtime.onSuspend</a></code>
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| + event if you need to do last second cleanup before your event page
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| + is shut down. However, we recommend persisting periodically instead.
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| + That way if your extension crashes without receiving
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| + <code>onSuspend</code>, no data will typically be lost.
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| +
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| + <li>If your extension uses <code>window.setTimeout()</code> or
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| + <code>window.setInterval()</code>, switch to using the
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| + <a href="alarms.html">alarms API</a> instead. DOM-based timers won't
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| + be honored if the event page shuts down.
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| +
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| + <li>If your extension uses,
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| + <code><a href="extension.html#method-getBackgroundPage">chrome.extension.getBackgroundPage()</a></code>,
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| + switch to
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| + <code><a href="runtime.html#method-getBackgroundPage">chrome.runtime.getBackgroundPage()</a></code>
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| + instead. The newer method is asynchronous so that it can start the event
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| + page if necessary before returning it.
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| +
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| + <li>If you're using <a href="messaging.html">message passing</a>, be sure
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| + to close unused message ports. The event page will not shut down until all
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| + message ports are closed.
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| +</ol>
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| +</p>
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|
|