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• 浏览器兼容性
• 相关话题

当 getAvailability () method is called, the user agent MUST run the following steps:

输入

presentationUrls , a list of presentation request URLs

输出

P ， Promise

1. If one of the following conditions is true:
   • The result of running the prohibits mixed security contexts algorithm on the document's settings object is "Prohibits Mixed Security Contexts" and presentationUrl 是 a priori unauthenticated URL .
   • The document object's active sandboxing flag set 拥有 sandboxed presentation browsing context flag set.
   Run the following substeps:
   1. 返回 Promise rejected with a SecurityError .
   2. Abort these steps.
2. Let P be a new Promise .
3. 返回 P , but continue running these steps in parallel .
4. If the user agent is unable to monitor the list of available presentation displays for the entire duration of the controlling browsing context (e.g., because the user has disabled this feature), then:
   1. Resolve P with a new PresentationAvailability object with its value 特性被设为 false .
   2. Abort all the remaining steps.
5. If the user agent is unable to continuously monitor the list of available presentation displays but can find presentation displays in order to start a connection, then:
   1. Reject P 采用 NotSupportedError 异常。
   2. Abort all the remaining steps.
6. If there exists a tuple ( A , presentationUrls ) 在 set of availability objects , then:
   1. Resolve P with A .
   2. Abort all the remaining steps.
7. Let A be a new PresentationAvailability object with its value property set as follows:
   1. false 若 list of available presentation displays is empty.
   2. true if there is at least one compatible presentation display for some member of presentationUrls . Meaning there is an entry (presentationUrl, display) 在 list of available presentation displays for some presentationUrl in presentationUrls .
   3. false 否则。
8. Create a tuple ( A , presentationUrls ) and add it to the set of availability objects .
9. Run the algorithm to monitor the list of available presentation displays .
10. Resolve P with A .

浏览器兼容性

The compatibility table on this page is generated from structured data. If you'd like to contribute to the data, please check out https://github.com/mdn/browser-compat-data and send us a pull request. 更新 GitHub 上的兼容性数据

	桌面						移动
	Chrome	Edge	Firefox	Internet Explorer	Opera	Safari	Android webview	Chrome for Android	Firefox for Android	Opera for Android	Safari on iOS	Samsung Internet
getAvailability	Chrome 48	Edge ≤79	Firefox 51	IE No	Opera 35	Safari ?	WebView Android No	Chrome Android 48	Firefox Android 51	Opera Android 35	Safari iOS ?	Samsung Internet Android 5.0

图例

完整支持

完整支持

不支持

不支持

兼容性未知 ?

兼容性未知

实验。期望将来行为有所改变。

实验。期望将来行为有所改变。

用户必须明确启用此特征。

用户必须明确启用此特征。

元数据

• 最后修改： 2019 年 3 月 23 日