Listener in a Content Script

Question

Let me explain my issue. I'm currently developing an Google Chrome Extension which inject a toolbar as an iframe in every web page.

The problem is that i need in some case to hide the toolbar, re-display it and things like that. Basicelly i was thinking to put my listener on my background-page, but it's useless because this page can't manipulate graphicely the object. So my plan was to put this listener on a content_script (who can manipulate graphiquely the objet). But the second problem is that a content-script in opposite to a background-page is not executed all the time but only once.

So i'm asking myself if it's possible to make a content-script sounds like a background-page, by putting a loop on it or something like that...

Thanks in advance.

I've tried this :

manifest.json

{   
    "background_page" : "background.html",
    "browser_action" :
    {
        "default_icon" : "images/extension.png"
        //"popup" : "activateToolbar.html"
    },
    "content_scripts": 
    [ {
          "all_frames": true,
          "css": ["css/yourtoolbar.css"],
          "js": ["js/jquery.js", "js/yourtoolbar.js", "js/listener.js"],
          "matches": ["http://*/*"],
          "run_at": "document_end"
    } ], 
    "permissions" : ["tabs", "unlimitedStorage", "http://*/*", "notifications"],    
    "name" : "YourToolbar",
    "version" : "1.1",
    "description" : "Make your own Toolbar"
}

toolbar.html

<!-- Close Button -->
            <a href="javascript:hideToolbar()"><input type="image" src="images/close.png" name="close" width="18" height="18"></a>

Tool.js

function hideToolbar()
{
    chrome.extension.sendRequest({action : "hideToolbar"});
    window.webkitNotifications.createHTMLNotification('instantMessage.html', 'Ask Show Menu').show();
}

listener.js

chrome.extension.onRequest.addListener(function(request, sender, sendResponse){
    if(request.action)
    {
        $('body').remove();
        console.log('Received Start');
        alert(request.action);
        console.log('Received End');
    }
    else
    {
        console.log('nothing');
        alert('Not For Me [listener.js]');
    }
});

background.js

chrome.extension.onRequest.addListener(function(request, sender, sendResponse) 
{   
    if(request.newTab) 
    {
        // Create a new Tab
        chrome.tabs.create({url: request.newTab});
    }
    else if(request.newWindow)
    {
        // Create a new Window
        chrome.windows.create({url: request.newWindow});
    }
    else if(request.action)
    {       
        chrome.tabs.getAllInWindow(null, function(tabs) {
          $.each(tabs, function() {
            chrome.tabs.sendRequest(this.id, {"action":"hideToolbar"} );
          });
        });
    }
});

But the problem is that the addListener didn't block the execution and he just didn't catch anything...

Answer 1

To send a request from a background page to a content script you need to use chrome.tabs.sendRequest (not chrome.extension.sendRequest) and provide tab id.

In a content script you don't need to periodically create chrome.extension.onRequest.addListener, just create it once and it will be there permanently.

EDIT

To send a request from a content script you need to run chrome.extension.sendRequest there and add chrome.extension.onRequest.addListener to a background page.