From 218934fa2ed1c702a6d3923d2aa2cc6b43c48684 Mon Sep 17 00:00:00 2001 From: Peter Bengtsson Date: Tue, 8 Dec 2020 14:43:23 -0500 Subject: initial commit --- .../web/api/window/requestidlecallback/index.html | 119 +++++++++++++++++++++ 1 file changed, 119 insertions(+) create mode 100644 files/zh-tw/web/api/window/requestidlecallback/index.html (limited to 'files/zh-tw/web/api/window/requestidlecallback/index.html') diff --git a/files/zh-tw/web/api/window/requestidlecallback/index.html b/files/zh-tw/web/api/window/requestidlecallback/index.html new file mode 100644 index 0000000000..743e7b2a39 --- /dev/null +++ b/files/zh-tw/web/api/window/requestidlecallback/index.html @@ -0,0 +1,119 @@ +--- +title: window.requestIdleCallback() +slug: Web/API/Window/requestIdleCallback +translation_of: Web/API/Window/requestIdleCallback +--- +
{{APIRef("HTML DOM")}}{{SeeCompatTable}}
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The window.requestIdleCallback() method queues a function to be called during a browser's idle periods. This enables developers to perform background and low priority work on the main event loop, without impacting latency-critical events such as animation and input response. Functions are generally called in first-in-first-out order; however, callbacks which have a timeout specified may be called out-of-order if necessary in order to run them before the timeout elapses.

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You can call requestIdleCallback() within an idle callback function to schedule another callback to take place no sooner than the next pass through the event loop.

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Syntax

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var handle = window.requestIdleCallback(callback[, options])
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Return value

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An ID which can be used to cancel the callback by passing it into the {{domxref("window.cancelIdleCallback()")}} method.

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Parameters

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callback
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A reference to a function that should be called in the near future, when the event loop is idle. The callback function is passed a {{domxref("IdleDeadline")}} object describing the amount of time available and whether or not the callback has been run because the timeout period expired.
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options {{optional_inline}}
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Contains optional configuration parameters. Currently only one property is defined: +
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  • timeout: If timeout is specified and has a positive value, and the callback has not already been called by the time timeout milliseconds have passed, the timeout will be called during the next idle period, even if doing so risks causing a negative performance impact.
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Example

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See our complete example in the article Cooperative Scheduling of Background Tasks API.

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Specifications

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SpecificationStatusComment
{{SpecName('Background Tasks')}}{{Spec2('Background Tasks')}}Initial definition.
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Browser compatibility

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{{CompatibilityTable}}

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FeatureChromeFirefox (Gecko)Internet ExplorerOperaSafari (WebKit)
Basic support{{CompatChrome(47)}}{{CompatGeckoDesktop(53)}} [1]{{CompatNo}}{{CompatOpera(34)}}{{CompatNo}}
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FeatureAndroid WebviewChrome for AndroidFirefox Mobile (Gecko)Firefox OSIE MobileOpera MobileSafari Mobile
Basic support{{CompatChrome(47)}}{{CompatChrome(47)}}{{CompatGeckoMobile(53)}} [1]{{CompatUnknown}}{{CompatUnknown}}{{CompatUnknown}}{{CompatUnknown}}
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[1] requestIdleCallback() is implemented in Firefox 53 but is disabled by default; to enable it, set the preference dom.requestIdleCallback.enabled to true. It is enabled by default starting in Firefox 55.

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See also

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