javascript - chrome扩展InjectDetails中文档的含义

Question

我在 Chrome 扩展代码中使用 InjectDetails 对象。我对 runAt 字段中引用的文档有点困惑。

这是来自documentation的片段

runAt ( optional enum of "document_start", "document_end", or "document_idle" )

这里引用了哪个文档？可能的选项是:-

• 原始文档(浏览器中加载的父框架)。
• 将要注入(inject) JS/Css 的文档。 (原始文档中可能有多个iframe)
• 文档在后台运行为background.html

我应该如何验证这一点？

Answer 1

如果allFrames为true，则“document”仅指顶级文档。
否则，它引用每个匹配框架的文档(例如顶级、iframe)。

您可以在 Content scripts 找到有关 run_at 的更多信息。文档:

run_at    string

Optional. Controls when the files in js are injected. Can be "document_start", "document_end", or "document_idle". Defaults to "document_idle".

In the case of "document_start", the files are injected after any files from css, but before any other DOM is constructed or any other script is run.

In the case of "document_end", the files are injected immediately after the DOM is complete, but before subresources like images and frames have loaded.

In the case of "document_idle", the browser chooses a time to inject scripts between "document_end" and immediately after the window.onload event fires. The exact moment of injection depends on how complex the document is and how long it is taking to load, and is optimized for page load speed.

Note: With "document_idle", content scripts may not necessarily receive the window.onload event, because they may run after it has already fired. In most cases, listening for the onload event is unnecessary for content scripts running at "document_idle" because they are guaranteed to run after the DOM is complete. If your script definitely needs to run after window.onload, you can check if onload has already fired by using the document.readyState property.

PS。属性名称采用驼峰命名法 chrome.tabs.executeScript (runAt, allFrames)，但在 list 文件中拼写为下划线 (run_at, all_frames)。