We Keep Coding

Chrome Extension Content-Script as Listener & Popup as Sender, But Gives Receiving End Does Not Exist

Answer Found
This extension is for google meet. What I have written in manifest.json is wrong, line "matches": ["*://*.meet.google.com/*"], should be "matches": ["*://meet.google.com/*"],
Original Question
I have this chrome extension, I want to let my contentScript.js to search for an element (tag) in a webpage when I press a button in popup.html. I set the sending message part in popup.js and the sending seems to work fine. But when I tried to receive it on the contentScript.js, console.log gives me Unchecked runtime.lastError: Could not establish connection. Receiving end does not exist.
May someone please help me, any suggestions are welcome.
Code snippets:
popup.js
retrieveTabId();
function retrieveTabId() {
chrome.tabs.query({currentWindow: true, active: true}, function (tabs) {
var activeTab = tabs[0];
console.log("tabID", activeTab.id);
tabId = activeTab.id;
});
}
document.getElementById("btn").addEventListener('click', function (){
chrome.tabs.sendMessage(tabId, {type: "listener"}, function(response) {
console.log((response.success));
});
console.log("tabID", tabId);
})
content-script.js
chrome.runtime.onMessage.addListener(
function (request, sender, sendResponse) {
if (request.type == 'listener') {
try {
let textarea = document.getElementsByTagName('textarea');
if (textarea.length == 0) {
sendResponse({success: false});
}
else {
console.log('find node -- textarea' + textarea);
sendResponse({success: true});
}
}
catch (e){
console.log(e);
sendResponse({success: false});
}
}
}
);
manifest.json
{
"name": "name",
"description": "Build an Extension!",
"version": "1.0",
"manifest_version": 3,
"permissions": ["storage", "activeTab", "scripting", "downloads", "notifications", "<all_urls>", "tabs"],
"action": {
"default_popup": "popup.html"
},
"background": {
"service_worker": "background.js"
},
"content_scripts": [{
"matches": ["*://*.meet.google.com/*"],
"js": ["contentScript.js"]
}]
}

send a message from content script to popup script

i'm trying to send a message from my content script to my popup script because i need to use popup DOM when a page is loaded, here's what i tried :
contentScript.js
window.addEventListener("load", function() {
chrome.runtime.sendMessage({
"action": "init"
});
})
popup.js
chrome.runtime.onMessage.addListener(function (request, sender, sendResponse) {
if (request.action == "init") {
alert('Initialisation demandée...')
} else {
alert('Je n\'ai pas compris')
}
})
manifest.json
{
"manifest_version": 2,
"name": "Youtube color modifier",
"description": "Change youtube colors",
"version": "1.0",
"page_action": {
"default_icon": "icon.png",
"default_title": "Youtube color modifier",
"default_popup": "popup.html"
},
"permissions": [
"activeTab"
],
"content_scripts": [{
"matches": ["<all_urls>"],
"js": ["contentScript.js"]
}]
}
Thank you for helping a noob :))

If you have a content script, it will be run everytime you (re)load the page, assuming that the page you are visiting is registered in the manifest.json.
So instead of this:
window.addEventListener("load", function() {
chrome.runtime.sendMessage({
"action": "init"
});
})
simply try this:
chrome.runtime.sendMessage({
"action": "init"
});

Error on calling Javascript APIs within Firefox extension

I am currently building a web extension and in the stage of porting between browsers. On moving from Chrome to Firefox I am coming against an issue in using the runtime.sendMessage API that allows me to talk between the content and background scripts.
The message code in the content script:
browser.runtime.sendMessage('d089938d-ba63-4c40-98ab-b8515db1bbca', { greeting: "screenshot-please" }, function (response) {
localStorage.setItem("image", response.farewell);
});
var image = localStorage.getItem("image");
The Background script:
var img = saved-image;
browser.runtime.onMessage.addListener(
function (request, sender, sendResponse) {
if(request.greeting === "screenshot-please"){
sendResponse({
farewell: img
});
}
}
);
and the manifest:
{
"description": "...",
"manifest_version": 2,
"name": "...",
"permissions": [
"find",
"tabs",
"activeTab",
"<all_urls>"
],
"applications": {
"gecko": {
"id": "..."
}
},
"background": {
"scripts": ["/JavaScript/moz-initialPopup.js"]
},
"content_scripts": [
{
"all_frames": true,
"matches": ["*://127.0.0.1:3000/*"],
"js": ["Javascript/dataGrab.js"]
}
],
"icons": {
"48": "..."
},
"browser_action": {
"browser_style": true,
"default_title": "...",
"default_icon": {
"48": "..."
}
},
"version": "1.0"
}
When in chrome (replace all instances of *browser with *chrome) this messaging system works fine. When in firefox, in the developer tools I get 'ReferenceError: browser is not defined'.
Can anyone assist me in why I would not be able to access the browser here?

Chrome Extension - Notification on Certain Web Pages

I'm looking to pop up a chrome notification whenever the user visits certain web pages e.g. 'www.amazon.com' or 'google.com' etc. The extension loads into chrome perfectly fine with no errors, but the notification doesn't pop up when I head to those specific pages.
I currently have the below scripts.
manifest.json
{
"name": "Test",
"version": "0.0.1",
"manifest_version": 2,
"description": "This extension was created with the awesome extensionizr.com",
"homepage_url": "http://www.test.co.uk",
"icons": {
"16": "icons/icon16.png",
"48": "icons/icon48.png",
"128": "icons/icon128.png"
},
"default_locale": "en",
"background": {
"page": "src/bg/background.html",
"persistent": true
},
"options_page": "src/options/index.html",
"browser_action": {
"default_icon": "icons/icon19.png",
"default_title": "browser action demo",
"default_popup": "src/browser_action/browser_action.html"
},
"permissions": ["notifications"],
"content_scripts": [
{
"matches": ["http://www.amazon.com/*", "http://amazon.co.uk/*"],
"js": ["js/script.js"]
}
]
}
js/script.js
if(onCertainWebsitesNeedNotificationAppearTrue) {
// send message to background script
chrome.runtime.sendMessage({greeting: "hello"}, function(response) {
});
}
background.js
chrome.extension.onMessage.addListener(
function(request, sender, sendResponse) {
chrome.pageAction.show(sender.tab.id);
sendResponse();
});
chrome.runtime.onMessage.addListener(
function(request, sender, sendResponse) {
//alert("good");
if (request.greeting == "hello")
createNotification();
});
function createNotification(){
var opt = {type: "basic",title: "Your Title",message: "Your message",iconUrl: "128.png"}
chrome.notifications.create("notificationName",opt,function(){});
//include this line if you want to clear the notification after 5 seconds
setTimeout(function(){chrome.notifications.clear("notificationName",function(){});},10000);
}
New to chrome extension coding so any help would be appreciated!

onCertainWebsitesNeedNotificationAppearTrue isn't defined anywhere so the code is not executed and the message is not sent.
Use the devtools debugger to diagnose the problems.
Also move the code from chrome.extension.onMessage callback inside chrome.runtime.onMessage callback and remove the former.

chrome extension to Send Message from popup to content script

I,am developing an extension in which i have to extract data from linkedin profile page when user press button on popup. I,am passing message from the popup.js page to contentscript and in response i will get data extracted from linkedin profile page by contentscript so that i can display it in popup.html. But I,am getting error when i inspected the popup.html. The error is:
Port: Could not establish connection. Receiving end does not exist. lastError:29
Error in event handler for 'undefined': Cannot read property 'farewell' of undefined
TypeError: Cannot read property 'farewell' of undefined
at chrome-extension://kdfgoafjicddfffdbfofdmckejemfije/popup.js:6:25
at <error: illegal access>
at Event.dispatchToListener (event_bindings:356:21)
at Event.dispatch_ (event_bindings:342:27)
at Event.dispatch (event_bindings:362:17)
at Object.chromeHidden.Port.dispatchOnDisconnect (miscellaneous_bindings:258:27)
For reference, my manifest file is:
{
"name": "SoftwareGrid",
"version": "0.5",
"icons": { "16": "icons/16.png","48": "icons/48.png", "128": "icons/128.png" },
"description": "Shows user cresidentials on Linkedin",
"permissions": [
"cookies",
"tabs",
"http://www.linkedin.com/*"
],
"browser_action": {
"default_title": "Show Profile",
"default_icon": { "16": "icons/16.png","48": "icons/48.png", "128": "icons/128.png" },
"default_popup": "popup.html"
},
"background": {
"scripts": ["jquery-1.7.2.min.js","background.js"]
},
"content_scripts": [{
"matches": ["http://www.linkedin.com/*"],
"all_frames": true,
"js": ["jquery-1.7.2.min.js", "script.js"],
"run_at": "document_end"
}],
"web_accessible_resources": [
"icons/i1.png"
],
"manifest_version": 2
}
My popup.js file:
function sendClicks() {
console.log("popup.js > sendClicks()");
chrome.tabs.query({active: true, currentWindow: true}, function(tabs) {
chrome.tabs.sendMessage(tabs[0].id, {greeting: "hello"}, function(response) {
console.log(response.farewell);
});
});
console.log("avra' inviato?");
}
$(function() {
console.log("popup.js > OMD Extension ready");
$('#sendclicks').click(function(){
sendClicks();
});
});
My contentscript file
chrome.runtime.onMessage.addListener(
function(request, sender, sendResponse) {
console.log(sender.tab ?
"from a content script:" + sender.tab.url :
"from the extension");
if (request.greeting == "hello")
sendResponse({farewell: "goodbye"});
});
Plz help!

You may have to add this in your manifest:
"permissions" : ["tabs"]