Chrome扩展程序-onMessageExternal未定义

Question

Im trying to build an extension that interacts with an internal app, and I'm looking at the documentation for the external messaging stuff, but whenever I try and access chrome.runtime.onMessageExternal.addListener , I get an error saying chrome.runtime.onMessageExternal is undefined. Same thing for onConnectExternal

manifest,json

{
    "manifest_version": 2,

    "name":           "My Extension",
    "description":    "My Desc",
    "version":        "0.2",

    "externally_connectable": {
        "matches": [
            "http://*.mysite.com/*"
        ]
    },

    "author": "Aaron Scherer",

    "content_scripts": [
        {
            "matches": [
                "http://*.mysite.com/*"
            ],
            "js":      ["js/script.js"]
        }
    ]
}

js/script.js

chrome.runtime.onMessageExternal.addListener(
    function( request, sender, sendResponse ) {
        debugger;
        console.debug( request  );
        console.debug( sender );
        console.debug( sendResponse  );
} );

website's js

chrome.runtime.sendMessage( 'myextid', { test: 'test' } );

Answer 1

chrome.runtime.onMessageExternal is only available in the background page, not in a content script. If you want to use this api to talk to content scripts you could relay the messages through the background page.

Another alternative is to use the standard window.postMessage . If you set a listener for 'message' with window.addEventListener in your content script you can receive messages sent from the page, and vice versa.