How to get access to variable app from content script app.js in background script background.js?

Here is how I try it (background.js):

chrome.tabs.executeScript(null, { file: "app.js" }, function() {
   app.getSettings('authorizeInProgress'); //...
});

Here is what I get:

Here is manifest.json:

{
  "name": "ctrl-vk",
  "version": "0.1.3",
  "manifest_version": 2,
  "description": "Chrome extension for ctrl+v insertion of images to vk",

  "content_scripts": [{
    "matches": [
        "http://*/*",
        "https://*/*"
    ],
    "js": ["jquery-1.9.1.min.js"
    ],
    "run_at": "document_end"
  }],

  "web_accessible_resources": [
    "jquery-1.9.1.min.js"
  ],

  "permissions" : [
    "tabs",
    "http://*/*",
    "https://*/*"
  ],

  "background": {
    "persistent": false,
    "scripts": ["background.js"]
  }
}

Full code for instance, at github

How to get access to variable app from content script app.js in background script background.js?

Here is how I try it (background.js):

chrome.tabs.executeScript(null, { file: "app.js" }, function() {
   app.getSettings('authorizeInProgress'); //...
});

Here is what I get:

Here is manifest.json:

{
  "name": "ctrl-vk",
  "version": "0.1.3",
  "manifest_version": 2,
  "description": "Chrome extension for ctrl+v insertion of images to vk.",

  "content_scripts": [{
    "matches": [
        "http://*/*",
        "https://*/*"
    ],
    "js": ["jquery-1.9.1.min.js"
    ],
    "run_at": "document_end"
  }],

  "web_accessible_resources": [
    "jquery-1.9.1.min.js"
  ],

  "permissions" : [
    "tabs",
    "http://*/*",
    "https://*/*"
  ],

  "background": {
    "persistent": false,
    "scripts": ["background.js"]
  }
}

Full code for instance, at github

https://github./MaxLord/ctrl-vk/tree/with_bug

• javascript
• google-chrome-extension

• I was figured out, what when we pass first argument as null to executeScript() - this mean that we trying to execute script in current tab. It is obviously not we want to get.. We currently need a way how to get this damn tab's id.. – milushov Commented Feb 16, 2013 at 23:38

3 Answers 3

To avoid above error use following code

if (tab.url.indexOf("chrome-devtools://") == -1) {
    chrome.tabs.executeScript(tabId, {
        file: "app.js"
    }, function () {

        if (app.getSettings('authorizeInProgress')) {
            alert('my tab');
            REDIRECT_URI = app.getSettings('REDIRECT_URI');
            if (tab.url.indexOf(REDIRECT_URI + "#access_token") >= 0) {
                app.setSettings('authorize_in_progress', false);
                chrome.tabs.remove(tabId);
                return app.finishAuthorize(tab.url);
            }
        } else {
            alert('not my');
        }

    });
}

instead of

chrome.tabs.executeScript(null, {
    file: "app.js"
}, function () {

    if (app.getSettings('authorizeInProgress')) {
        alert('my tab');
        REDIRECT_URI = app.getSettings('REDIRECT_URI');
        if (tab.url.indexOf(REDIRECT_URI + "#access_token") >= 0) {
            app.setSettings('authorize_in_progress', false);
            chrome.tabs.remove(tabId);
            return app.finishAuthorize(tab.url);
        }
    } else {
        alert('not my');
    }

});

Explanation

• chrome://extensions/ page also fires chrome.tabs.onUpdated event, to avoid it we have to add a filter to skip all dev-tool pages.

(Would've submitted this as ment to the accepted answer but still lack the required reputation)

You should also give the tabId to chrome.tabs.executeScript as first argument when you have it. Otherwise you risk user switching windows/tabs right after requesting a URL and background.js doing executeScript against wrong page.

While fairly obvious on hindsight it threw me for a loop when I got that same error message "Cannot access contents of url "chrome-devtools://.." even though my chrome.tabs.onUpdated eventhandler was checking that the page user requested had some specific domain name just before doing the executeScript call.

So keep in mind, chrome.tabs.executeScript(null,..) runs the script in active window, even if the active window might be developer tools inspector.

We should notice that, in the manifest cofig：

"content_scripts": [{
"matches": [
    "http://*/*",
    "https://*/*"
],
"js": ["jquery-1.9.1.min.js"
],

in the "matches" part, only http, https are matched, so if you load your extension in page like: 'chrome://extensions/', or 'file:///D:xxx', that error will occur.

You may load your extension in the page with the url 'http://'; or add more rules in your 'matches' array.