在内容脚本中从background.js调用事件侦听器

Question

I have an event listener in background.js as follows:

chrome.webRequest.onHeadersReceived.addListener(function(details){
 .....
})

How can I call this event listener from content script?

Answer 1

You cannot call or basically say trigger any webrequest api event listener from content script. Basically the definition of onHeadersReceived is as below on the offical doumentation.

Fires each time that an HTTP(S) response header is received. Due to redirects and authentication requests this can happen multiple times per request. This event is intended to allow extensions to add, modify, and delete response headers, such as incoming Set-Cookie headers. The caching directives are processed before this event is triggered, so modifying headers such as Cache-Control has no influence on the browser's cache. It also allows you to redirect the request.

Please checkout the official documentation of the event you are listening to for better clarity and options.

But you can always add custom eventListners on background.js scripts which you are trigger from content scripts using the messaging feature. A simple example is depicted in the documentation . Where you send a custom message from content script and receive the message on background script. This way you can communicate with background script.