Question

I am looking to create an extension for a particular site to provide additional formatting and sharing options that they don’t currently have.

I am having issues getting things to communicate properly and there doesn’t seem to be a clearly laid out example.

Manifest:

{
    "name": "Test",
    "description": "Testing.",
    "version": "1.0",
    "background_page": "background.html",
    "permissions": [
        "tabs", "http://www.sitedomain.com/*"
    ],
    "content_scripts": [
        {
            "matches": ["*://*.sitedomain.com/*"],
            "js": ["jquery.min.js", "test.js"],
            "css": ["test.css"]
        }
    ]
}

Content Script:

$(document).ready(function () {
    alert('test js fired');
    $("#ColumnContainer div.item").each(function () {
        $(this).css("background-color", "skyBlue");
        var itemId = $(this).children("a.itemImage").attr("href");
        $(this).children(".details").append("<a href=\"javscript:void(false);\"  onclick=\"gotoItem('" + itemId + "');\">Goto Item</a>");

    });
});
chrome.extension.onRequest.addListener(function (request, sender, sendResponse) {
    alert('listener request');
    alert(request);
}); 

JavaScript of Background HTML:

    chrome.tabs.onUpdated.addListener(function (tabId, changeInfo, tab) {
        if (changeInfo.status == "complete") {
            if (tab.url.indexOf("sitedomain.com") > -1) {

                chrome.tabs.executeScript(null, {file: "test.js"});
            }

        }
    });
    chrome.tabs.sendRequest(tabId, request, responseCallback);
    function responseCallback() {
        alert('response callback');
    }
    function gotoItem(itemId) {
        alert('goto Item - ' + itemId);
    }

The above code does append the link and change the styling on the client page when the sitedomain.com is loaded. However, I haven’t had any luck getting the gotoItem method to fire, Chrome Dev Tools shows undefined. I have tried various combinations, but just can’t quite grasp the listeners and requests yet.

I would really like to see a clean sample that just shows how to call a method from each site.

Answer 1

I see two issues with your code. 1) the gotoItem function is defined in the background page and content_scripts can’t access functions there. 2) content_scripts and javascript on pages they are injected into can not interact so your onclick can’t be part of the links html.

To fix #1 is as simple as moving the gotoItem function to be in the content_script.

To fix #2 something like the following should work.

$("#ColumnContainer div.item").each(function(){
    $(this).css("background-color","skyBlue");
    var itemId = $(this).children("a.itemImage").attr("href");
    var $link = $('<a href="javscript:void(false);">Goto Item</a>');
    $link.click(function() {
      gotoItem(itemId);
    }
    $(this).children(".details").append($link);
});

You may have to modify how itemId gets passed.