After preparing the migration of my chrome manifest V2 extension to manifest V3 and reading about the problems with persistent service workers I prepared myself for a battle with the unknown. My V2 background script uses a whole bunch of globally declared variables and I expected I need to refactor that.
But to my great surprise my extension background script seems to work out of the box without any trouble in manifest V3. My extension uses externally_connectable. The typical use case for my extension is that the user can navigate to my website 'bla.com' and from there it can send jobs to the extension background script.
My manifest says:
"externally_connectable": {
"matches": [
"*://localhost/*",
"https://*.bla.com/*"
]
}
My background script listens to external messages and connects:
chrome.runtime.onMessageExternal.addListener( (message, sender, sendResponse) => {
log('received external message', message);
});
chrome.runtime.onConnectExternal.addListener(function(port) {
messageExternalPort = port;
if (messageExternalPort && typeof messageExternalPort.onDisconnect === 'function') {
messageExternalPort.onDisconnect(function () {
messageExternalPort = null;
})
}
});
From bla.com I send messages to the extension as follows
chrome.runtime.sendMessage(EXTENSION_ID, { type: "collect" });
From bla.com I receive messages from the extension as follows
const setUpExtensionListener = () => {
// Connect to chrome extension
this.port = chrome.runtime.connect(EXTENSION_ID, { name: 'query' });
// Add listener
this.port.onMessage.addListener(handleExtensionMessage);
}
I tested all scenarios including the anticipation of the famous service worker unload after 5 minutes or 30 seconds inactivity, but it all seems to work. Good for me, but something is itchy. I cannot find any documentation that explains precisely under which circumstances the service worker is unloaded. I do not understand why things seem to work out of the box in my situation and why so many others experience problems. Can anybody explain or refer to proper documentation. Thanks in advance.
I am in the process of building a Chrome extension, and for the whole thing to work the way I would like it to, I need an external JavaScript script to be able to detect if a user has my extension installed.
For example: A user installs my plugin, then goes to a website with my script on it. The website detects that my extension is installed and updates the page accordingly.
Is this possible?
Chrome now has the ability to send messages from the website to the extension.
So in the extension background.js (content.js will not work) add something like:
chrome.runtime.onMessageExternal.addListener(
function(request, sender, sendResponse) {
if (request) {
if (request.message) {
if (request.message == "version") {
sendResponse({version: 1.0});
}
}
}
return true;
});
This will then let you make a call from the website:
var hasExtension = false;
chrome.runtime.sendMessage(extensionId, { message: "version" },
function (reply) {
if (reply) {
if (reply.version) {
if (reply.version >= requiredVersion) {
hasExtension = true;
}
}
}
else {
hasExtension = false;
}
});
You can then check the hasExtension variable. The only drawback is the call is asynchronous, so you have to work around that somehow.
Edit:
As mentioned below, you'll need to add an entry to the manifest.json listing the domains that can message your addon. Eg:
"externally_connectable": {
"matches": ["*://localhost/*", "*://your.domain.com/*"]
},
2021 Update:
chrome.runtime.sendMessage will throw the following exception in console if the extension isn't installed or it's disabled.
Unchecked runtime.lastError: Could not establish connection. Receiving end does not exist
To fix this, add this validation inside the sendMessage callback
if (chrome.runtime.lastError) {
// handle error
}
I am sure there is a direct way (calling functions on your extension directly, or by using the JS classes for extensions), but an indirect method (until something better comes along):
Have your Chrome extension look for a specific DIV or other element on your page, with a very specific ID.
For example:
<div id="ExtensionCheck_JamesEggersAwesomeExtension"></div>
Do a getElementById and set the innerHTML to the version number of your extension or something. You can then read the contents of that client-side.
Again though, you should use a direct method if there is one available.
EDIT: Direct method found!!
Use the connection methods found here: https://developer.chrome.com/extensions/extension#global-events
Untested, but you should be able to do...
var myPort=chrome.extension.connect('yourextensionid_qwerqweroijwefoijwef', some_object_to_send_on_connect);
Another method is to expose a web-accessible resource, though this will allow any website to test if your extension is installed.
Suppose your extension's ID is aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa, and you add a file (say, a transparent pixel image) as test.png in your extension's files.
Then, you expose this file to the web pages with web_accessible_resources manifest key:
"web_accessible_resources": [
"test.png"
],
In your web page, you can try to load this file by its full URL (in an <img> tag, via XHR, or in any other way):
chrome-extension://aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa/test.png
If the file loads, then the extension is installed. If there's an error while loading this file, then the extension is not installed.
// Code from https://groups.google.com/a/chromium.org/d/msg/chromium-extensions/8ArcsWMBaM4/2GKwVOZm1qMJ
function detectExtension(extensionId, callback) {
var img;
img = new Image();
img.src = "chrome-extension://" + extensionId + "/test.png";
img.onload = function() {
callback(true);
};
img.onerror = function() {
callback(false);
};
}
Of note: if there is an error while loading this file, said network stack error will appear in the console with no possibility to silence it. When Chromecast used this method, it caused quite a bit of controversy because of this; with the eventual very ugly solution of simply blacklisting very specific errors from Dev Tools altogether by the Chrome team.
Important note: this method will not work in Firefox WebExtensions. Web-accessible resources inherently expose the extension to fingerprinting, since the URL is predictable by knowing the ID. Firefox decided to close that hole by assigning an instance-specific random URL to web accessible resources:
The files will then be available using a URL like:
moz-extension://<random-UUID>/<path/to/resource>
This UUID is randomly generated for every browser instance and is not your extension's ID. This prevents websites from fingerprinting the extensions a user has installed.
However, while the extension can use runtime.getURL() to obtain this address, you can't hard-code it in your website.
I thought I would share my research on this.
I needed to be able to detect if a specific extension was installed for some file:/// links to work.
I came across this article here
This explained a method of getting the manifest.json of an extension.
I adjusted the code a bit and came up with:
function Ext_Detect_NotInstalled(ExtName, ExtID) {
console.log(ExtName + ' Not Installed');
if (divAnnounce.innerHTML != '')
divAnnounce.innerHTML = divAnnounce.innerHTML + "<BR>"
divAnnounce.innerHTML = divAnnounce.innerHTML + 'Page needs ' + ExtName + ' Extension -- to intall the LocalLinks extension click here';
}
function Ext_Detect_Installed(ExtName, ExtID) {
console.log(ExtName + ' Installed');
}
var Ext_Detect = function (ExtName, ExtID) {
var s = document.createElement('script');
s.onload = function () { Ext_Detect_Installed(ExtName, ExtID); };
s.onerror = function () { Ext_Detect_NotInstalled(ExtName, ExtID); };
s.src = 'chrome-extension://' + ExtID + '/manifest.json';
document.body.appendChild(s);
}
var is_chrome = navigator.userAgent.toLowerCase().indexOf('chrome') > -1;
if (is_chrome == true) {
window.onload = function () { Ext_Detect('LocalLinks', 'jllpkdkcdjndhggodimiphkghogcpida'); };
}
With this you should be able to use Ext_Detect(ExtensionName,ExtensionID) to detect the installation of any number of extensions.
Another possible solution if you own the website is to use inline installation.
if (chrome.app.isInstalled) {
// extension is installed.
}
I know this an old question but this way was introduced in Chrome 15 and so I thought Id list it for anyone only now looking for an answer.
Here is an other modern approach:
const checkExtension = (id, src, callback) => {
let e = new Image()
e.src = 'chrome-extension://'+ id +'/'+ src
e.onload = () => callback(1), e.onerror = () => callback(0)
}
// "src" must be included to "web_accessible_resources" in manifest.json
checkExtension('gighmmpiobklfepjocnamgkkbiglidom', 'icons/icon24.png', (ok) => {
console.log('AdBlock: %s', ok ? 'installed' : 'not installed')
})
checkExtension('bhlhnicpbhignbdhedgjhgdocnmhomnp', 'images/checkmark-icon.png', (ok) => {
console.log('ColorZilla: %s', ok ? 'installed' : 'not installed')
})
I used the cookie method:
In my manifest.js file I included a content script that only runs on my site:
"content_scripts": [
{
"matches": [
"*://*.mysite.co/*"
],
"js": ["js/mysite.js"],
"run_at": "document_idle"
}
],
in my js/mysite.js I have one line:
document.cookie = "extension_downloaded=True";
and in my index.html page I look for that cookie.
if (document.cookie.indexOf('extension_downloaded') != -1){
document.getElementById('install-btn').style.display = 'none';
}
You could have the extension set a cookie and have your websites JavaScript check if that cookie is present and update accordingly. This and probably most other methods mentioned here could of course be cirvumvented by the user, unless you try and have the extension create custom cookies depending on timestamps etc, and have your application analyze them server side to see if it really is a user with the extension or someone pretending to have it by modifying his cookies.
There's another method shown at this Google Groups post. In short, you could try detecting whether the extension icon loads successfully. This may be helpful if the extension you're checking for isn't your own.
Webpage interacts with extension through background script.
manifest.json:
"background": {
"scripts": ["background.js"],
"persistent": true
},
"externally_connectable": {
"matches": ["*://(domain.ext)/*"]
},
background.js:
chrome.runtime.onMessageExternal.addListener(function(msg, sender, sendResponse) {
if ((msg.action == "id") && (msg.value == id))
{
sendResponse({id : id});
}
});
page.html:
<script>
var id = "some_ext_id";
chrome.runtime.sendMessage(id, {action: "id", value : id}, function(response) {
if(response && (response.id == id)) //extension installed
{
console.log(response);
}
else //extension not installed
{
console.log("Please consider installig extension");
}
});
</script>
Your extension could interact with the website (e.g. changing variables) and your website could detect this.
But there should be a better way to do this. I wonder how Google is doing it on their extension gallery (already installed applications are marked).
Edit:
The gallery use the chrome.management.get function. Example:
chrome.management.get("mblbciejcodpealifnhfjbdlkedplodp", function(a){console.log(a);});
But you can only access the method from pages with the right permissions.
A lot of the answers here so far are Chrome only or incur an HTTP overhead penalty. The solution that we are using is a little different:
1. Add a new object to the manifest content_scripts list like so:
{
"matches": ["https://www.yoursite.com/*"],
"js": [
"install_notifier.js"
],
"run_at": "document_idle"
}
This will allow the code in install_notifier.js to run on that site (if you didn't already have permissions there).
2. Send a message to every site in the manifest key above.
Add something like this to install_notifier.js (note that this is using a closure to keep the variables from being global, but that's not strictly necessary):
// Dispatch a message to every URL that's in the manifest to say that the extension is
// installed. This allows webpages to take action based on the presence of the
// extension and its version. This is only allowed for a small whitelist of
// domains defined in the manifest.
(function () {
let currentVersion = chrome.runtime.getManifest().version;
window.postMessage({
sender: "my-extension",
message_name: "version",
message: currentVersion
}, "*");
})();
Your message could say anything, but it's useful to send the version so you know what you're dealing with. Then...
3. On your website, listen for that message.
Add this to your website somewhere:
window.addEventListener("message", function (event) {
if (event.source == window &&
event.data.sender &&
event.data.sender === "my-extension" &&
event.data.message_name &&
event.data.message_name === "version") {
console.log("Got the message");
}
});
This works in Firefox and Chrome, and doesn't incur HTTP overhead or manipulate the page.
You could also use a cross-browser method what I have used.
Uses the concept of adding a div.
in your content script (whenever the script loads, it should do this)
if ((window.location.href).includes('*myurl/urlregex*')) {
$('html').addClass('ifextension');
}
in your website you assert something like,
if (!($('html').hasClass('ifextension')){}
And throw appropriate message.
If you have control over the Chrome extension, you can try what I did:
// Inside Chrome extension
var div = document.createElement('div');
div.setAttribute('id', 'myapp-extension-installed-div');
document.getElementsByTagName('body')[0].appendChild(div);
And then:
// On web page that needs to detect extension
if ($('#myapp-extension-installed-div').length) {
}
It feels a little hacky, but I couldn't get the other methods to work, and I worry about Chrome changing its API here. It's doubtful this method will stop working any time soon.
If you're trying to detect any extension from any website,
This post helped: https://ide.hey.network/post/5c3b6c7aa7af38479accc0c7
Basically, the solution would be to simply try to get a specific file (manifest.json or an image) from the extension by specifying its path. Here's what I used. Definitely working:
const imgExists = function(_f, _cb) {
const __i = new Image();
__i.onload = function() {
if (typeof _cb === 'function') {
_cb(true);
}
}
__i.onerror = function() {
if (typeof _cb === 'function') {
_cb(false);
}
}
__i.src = _f;
__i = null;
});
try {
imgExists("chrome-extension://${CHROME_XT_ID}/xt_content/assets/logo.png", function(_test) {
console.log(_test ? 'chrome extension installed !' : 'chrome extension not installed..');
ifrm.xt_chrome = _test;
// use that information
});
} catch (e) {
console.log('ERROR', e)
}
Here is how you can detect a specific Extension installed and show a warning message.
First you need to open the manifest file of the extension by going to chrome-extension://extension_id_here_hkdppipefbchgpohn/manifest.json and look for any file name within "web_accessible_resources" section.
<div class="chromewarning" style="display:none">
<script type="text/javascript">
$.get("chrome-extension://extension_id_here_hkdppipefbchgpohn/filename_found_in_ web_accessible_resources.png").done(function () {
$(".chromewarning").show();
}).fail(function () {
// alert("failed.");
});
</script>
<p>We have detected a browser extension that conflicts with learning modules in this course.</p>
</div>
Chrome Extension Manifest v3:
const isFirefox = chrome.runtime.OnInstalledReason.CHROME_UPDATE != "chrome_update";
For FireFox, I believe chrome.runtime.OnInstalledReason.BROWSER_UPDATE will be "browser_update": https://developer.mozilla.org/en-US/docs/Mozilla/Add-ons/WebExtensions/API/runtime/OnInstalledReason
I have followed this tutorial on setting up Parse push notification in a Windows Phone app. This is my code:
public App() {
// Global handler for uncaught exceptions.
UnhandledException += Application_UnhandledException;
// Standard XAML initialization
InitializeComponent();
// Phone-specific initialization
InitializePhoneApplication();
// Language display initialization
InitializeLanguage();
// Show graphics profiling information while debugging.
if (Debugger.IsAttached) {
// Display the current frame rate counters.
Application.Current.Host.Settings.EnableFrameRateCounter = true;
// Show the areas of the app that are being redrawn in each frame.
//Application.Current.Host.Settings.EnableRedrawRegions = true;
// Enable non-production analysis visualization mode,
// which shows areas of a page that are handed off to GPU with a colored overlay.
//Application.Current.Host.Settings.EnableCacheVisualization = true;
// Prevent the screen from turning off while under the debugger by disabling
// the application's idle detection.
// Caution:- Use this under debug mode only. Application that disables user idle detection will continue to run
// and consume battery power when the user is not using the phone.
PhoneApplicationService.Current.UserIdleDetectionMode = IdleDetectionMode.Disabled;
}
// Initialize the Parse client with your Application ID and .NET Key found on
// your Parse dashboard
ParseClient.Initialize("grpTmrClet8K35yeXg2HQKK8wl59VeC9ijH0I0dn", "os8EfSFq9maPBtDJ91Mq0xnWme8fLANhttTPAqKu");
// After calling ParseClient.Initialize():
this.Startup += async (sender, args) =>
{
// This optional line tracks statistics around app opens, including push effectiveness:
ParseAnalytics.TrackAppOpens(RootFrame);
// By convention, the empty string is considered a "Broadcast" channel
// Note that we had to add "async" to the definition to use the await keyword
await ParsePush.SubscribeAsync("testchannel");
};
}
// Code to execute when the application is launching (eg, from Start)
// This code will not execute when the application is reactivated
private async void Application_Launching(object sender, LaunchingEventArgs e) {
await ParseAnalytics.TrackAppOpenedAsync();
}
When I send a push notification from the Parse dashboard it doesn't get received. I have tried running both on the emulator (Windows Phone 8.0) and device (8.1), with app in foreground, background and closed with the same negative result.
When I use a channel like "testchannel" above and use the segment options, the channel name appears in the dropdown list of options indicating that the app is at least connecting Parse, but it just wont receive the notifications.
Hope someone can help me identify what I am missing. Thanks in advance.
If you are developing a Windows Phone 8.1 app, make sure you've enabled toast notification in the manifest file.
I don't quite understand everything about Parse just yet, but this is what works for me.
In App.xaml.cs:
public App()
{
this.InitializeComponent();
this.Suspending += this.OnSuspending;
ParseClient.Initialize("wSjuNTbtjVLRaedXvOoaf9S5cTbkuQohTulNZ2vS", "nWZMhXRet9Wotlgikb9aUdKf5GFtRiMvduw7w68z");
}
We subscribe and enable analytics OnLaunched:
protected async override void OnLaunched(LaunchActivatedEventArgs e)
//Generated codes go here
await ParsePush.SubscribeAsync("testchannel");
await ParseAnalytics.TrackAppOpenedAsync();
That would simply do the trick. You should modify the code according to your needs. Hope this helps.
I am trying to include subtitles on a Chromecast application I'm building.
I am using the default receiver application.
I am writing a chrome sender application using v1 of the chrome sender api.
According to the Chromecast Sender Api documentation, I should be passing in an array of track objects into the chrome.cast.media.MediaInfo object. My issue is, whenever I call chrome.cast.media.Track(trackId, trackType), it returns undefined. When I look through the public methods in chrome.cast.media, through console, I don't see anything related to Track. Link to documentation here.
Below is my loadMedia method where I try to include an array of track objects along with my LoadRequest as specified by the cast api. The commented out code is how I've seen closed-captioning handled in one of the cast Github repositories, but unfortunately I believe you have to handle that customData in your own custom receiver application.
Are subtitles through the chrome sender SDK possible yet, or does one have to build their own receiver application and specifically handle text tracking through passed in customData? Am I potentially using the wrong sender api?
function loadMedia() {
mediaUrl = decodeURIComponent(_player.sources.mp4);
var mediaInfo = new chrome.cast.media.MediaInfo(mediaUrl);
mediaInfo.contentType = 'video/mp4';
var track1 = new chrome.cast.media.Track(1, chrome.cast.media.TrackType.TEXT);
track1.trackContentId = "https://dl.dropboxusercontent.com/u/35106650/test.vtt";
mediaInfo.tracks = [track1];
var request = new chrome.cast.media.LoadRequest(mediaInfo);
// var json = {
// cc: {
// tracks: [{
// src: "https://dl.dropboxusercontent.com/u/35106650/test.vtt"
// }],
// active: 0
// }
// };
// request.customData = json;
session.loadMedia(request, onMediaDiscovered.bind(this, 'loadMedia'), onMediaError);
}
Currently, neither the Default nor the Styled Receivers support Closed Caption; you need to create your own. We have a sample in our GitHub repo that can be used for doing exactly that.
Update: Styled and Default receivers now support Tracks, see our documentations.
I have followed all the steps given in the documentation to register for a push notification from the Parse website. (All the steps in the sense I downloaded the default project and added event handler to handle the incoming toast notification).
ParseClient.Initialize("x0uNa3Q164SVGKbH4mxZJaxWxsuYtslB5tVPj893",
"cXFv9RQAoray9xFdwdcZCHXrrkrM6KNd0WyN194H");
this.Startup += async (sender, args) =>
{
// This optional line tracks statistics around app opens, including push effectiveness:
ParseAnalytics.TrackAppOpens(RootFrame);
// By convention, the empty string is considered a "Broadcast" channel
// Note that we had to add "async" to the definition to use the await keyword
await ParsePush.SubscribeAsync("");
};
ParsePush.ToastNotificationReceived += ParsePushOnToastNotificationReceived;
and the handler
private void ParsePushOnToastNotificationReceived(object sender,
NotificationEventArgs notificationEventArgs)
{
var s = new ShellToast();
s.Content = notificationEventArgs.Collection.Values.First();
s.Title = "My Toast";
s.Show();
}
private async void Application_Launching(object sender, LaunchingEventArgs e)
{
await ParseAnalytics.TrackAppOpenedAsync();
}
When I run the app in the emulator it registers the app and I can verify it in my dashboard. But as soon as I send push notification from the website number of registered devices will be shown as 0 and the app doesnt receive the notification.
One thing to mention is this behavior is not consistent. Sometimes the app does receive the notification. Can anyone mention the reason for this or any other point I am missing?
One thing to note is that ShellToast.Show() should only be used from background task. If you call it when an app is in the foreground, toast won't be shown. http://msdn.microsoft.com/en-US/library/windowsphone/develop/microsoft.phone.shell.shelltoast.show(v=vs.105).aspx
So, be sure your app is not in the foreground when you expect to see toast notification.
Firstly you will be shown toast notification only if the foreground app is not running. If your app is running when you receive push notification you have to do like:
void ParsePushOnToastNotificationReceived(object sender,
NotificationEventArgs notificationEventArgs)
{
Deployment.Current.Dispatcher.BeginInvoke(()=>{
// do anything
MessageBox.Show("got notification");
});
}
If your app is not running the os will handle the notification properly, you dont have to do anything.