chrome extension to run script on page load

google-chrome-devtools, google-chrome-extension, javascript

Solution

If you registered a callback to `chrome.tabs.executeScript(...)` to catch any errors, e.g.:

chrome.tabs.executeScript({ code: "console.log('dsff');" }, function() {
    if (chrome.runtime.lastError) {
         console.log("ERROR: " + chrome.runtime.lastError.message);
    }
});

you would notice the following error:

ERROR: Cannot access contents of url "...". Extension manifest must request permission to access this host.

So, you need to add the appropriate host match pattern to the `permissions` list in your manifest. E.g. to be able to inject code into any `http/https` page:

"permissions": ["*://*/*"]

Furthermore, if you omit the `tabId` argument of `chrome.tabs.executeScript(...)` it will apply to the currently active tab (which might defer from the one that fired the `onUpdated` event). So, also, make the following change:

chrome.tabs.executeScript(tab.id, { code: "console.log('dsff');" }, function() {...

Problem

I'm writing a chrome extension which should be capable of running a script on that page as soon as it has been loaded. I implemented the feature to run the code on clicking on extension icon but when I added code to run that script on page load its not working Manifest file ``` { "name": "", "description": "", "version": "1.0", "permissions": [ "activeTab", "tabs" ], "background": { "scripts": ["background.js"], "persistent": false }, "browser_action": { "default_title": "", "default_icon": "6a00e3982283618833019affd3c028970c.png" }, "manifest_version": 2 } ``` js file: ``` chrome.tabs.onUpdated.addListener( function ( tabId, changeInfo, tab ) { if ( changeInfo.status === "complete" ) { chrome.tabs.executeScript({ code: "console.log('dsff');" }); } }); ``` but despite this my js is not running when ever user changes the page in a tab

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