Only allow one active instance of a Chrome extension - google-chrome-extension

I have a Chrome extension which needs to be open only in one window per machine at a time.
What would be the best way to enforce this condition? For example, is there a mechanism to point the user to an existing tab running the extension, if there exists such a tab?
The relevant parts of my manifest file are as follows:
manifest.json
{
"manifest_version": 2,
"browser_action": {
"default_icon": "/img/favicon.ico",
"popup": "main.html"
},
"background": {
"scripts": ["open.js"]
}
}
And the open.js reads as follows:
open.js
chrome.browserAction.onClicked.addListener(function(tab) {
chrome.tabs.create({'url': chrome.extension.getURL('test.html')}, function(tab) {
});
});

Update Updated to also include focusing on a tab that is in a different window
Since no one posted the answer to this question here it is, taken from Rob W's github as linked in the comments under the question https://github.com/Rob--W/stackexchange-notifications/blob/8947b9982cd7b9e04ccf0ef23510571f39d33c4e/Chrome/using-websocket.js#L66-L82.
This is a more basic version replacing the openTab() function found in the original code with the basic command to open a new tab.
var options_url = chrome.extension.getURL('options.html');
chrome.tabs.query({
url: options_url
}, function(tabs) {
if (tabs.length == 0) {
chrome.tabs.create({ url: "main.html" });
} else {
// If there's more than one, close all but the first
for (var i=1; i<tabs.length; i++)
chrome.tabs.remove(tabs[i].id);
// And focus the options page
chrome.tabs.update(tabs[0].id, {active: true});
chrome.windows.update(tabs[0].windowId, {focused:true})
}
});

Related

Chrome extension contextmenus sendResponse doesn't work on some pages

I want to build a extension which is able to get the English word selected by users when reading some English articles and get the whole sentence at the same time.
↓ This is my background.js file. I use getSelection function to send a message to content.js to request a response which contains selection info.
//background.js
chrome.runtime.onInstalled.addListener((tableId, changeInfo, tab) => {
chrome.contextMenus.create({
id: 'addWords',
title: "Send \"%s\" to background",
contexts: ['all']
})
function getSelection(info, tab) {
if (info.menuItemId === "addWords") {
chrome.tabs.sendMessage(tab.id, {action: "getSelection"}, (response) => {
console.log(response);
});
}
}
chrome.contextMenus.onClicked.addListener(getSelection);
});
↓ This is my content.js file. I use onMessage to respond to the background's request.
//content.js
chrome.runtime.onMessage.addListener((request, sender, sendResponse) => {
if(request.action === "getSelection"){
let selection = window.getSelection();
if(selection.toString() !== ""){
let arr = selection.anchorNode.data.split(".");
let word = selection.toString();
let sentence = arr.find(str => str.includes(word))
alert(word);
sendResponse({word: word, sentence: sentence});
}
}
})
↓ This is my manifest.json file
{
"manifest_version": 3,
"name": "Words Repeater",
"description": "Repeat words what you want to memorize",
"version": "1.0.0",
"permissions": ["contextMenus", "activeTab", "tabs"],
"action": {
"default_popup": "popup.html"
},
"background": {
"service_worker": "./js/background.js"
},
"content_scripts": [
{
"matches": ["http://*/*", "https://*/*"],
"js": ["./js/content.js"]
}
]
}
The extension works correctly initially, but it fails after changing a website and I got a error "Unchecked runtime.lastError: Could not establish connection. Receiving end does not exist."
How to make the context menu run correctly on every tabs? Really appreicate your help!
Your onClicked event listener is misplaced inside onInstalled listener, so it will work only for less than a minute immediately after the installation/update until the background script is auto-terminated, then it will be ignored like it doesn't exist. Move it outside to properly re-register it every time the background script starts on an event like the context menu click.
When the extension is installed/updated its new content script won't be automatically injected into the currently opened tabs in Chrome/ium, so you'll have to do it explicitly yourself as shown here, but there's a much better alternative in cases like yours where the access to the page is necessary only on demand after the user invoked the extension: programmatic injection via executeScript in tandem with the activeTab permission.
remove content_scripts from manifest.json - now your extension won't require broad host permissions i.e. there'll be no installation warning in the web store.
remove "tabs" from "permissions" - it's not necessary and now there'll be no warning about observing the browser history.
add "scripting" to "permissions".
Consider limiting the contexts to "selection" to show it only when text is selected, and not show in the wrong contexts like the built-in menu of the extension's icon in the toolbar.
Parameters of chrome.runtime.onInstalled were incorrectly copied from chrome.tabs.onUpdated listener, but since they are unused you can remove them.
chrome.runtime.onInstalled.addListener(() => {
chrome.contextMenus.create({
id: 'addWords',
title: 'Send "%s" to background',
contexts: ['selection'],
});
});
chrome.contextMenus.onClicked.addListener(async (info, tab) => {
if (info.menuItemId === 'addWords') {
let word = info.selectionText.trim();
let sentence;
try {
[{ result: sentence }] = await chrome.scripting.executeScript({
target: {
tabId: tab.id,
frameIds: [info.frameId],
},
func: () => {
const selection = window.getSelection();
const arr = selection.anchorNode.data.split('.');
const word = selection.toString();
const sentence = arr.find(str => str.includes(word));
return sentence;
},
});
} catch (e) {} // invoked on a page that doesn't allow injection
console.log(word, sentence); // this prints in background console
}
});

Identify "tab" in background script as your own "newtab" page without "tabs" permission

The extension I've built has both the background script and overrides the "newtab" page.
Can I, without "tabs" or "all_urls" permission, know in the background script "chrome.tabs.onCreated.addListener" that my own newtab page has been opened? With "tabs" permission, I simply check the URL.
My ultimate goal is to take the focus from Omnibox and put it in my own input search on the newtab page. I have that working well now and the thing that I want to do is remove "tabs" permission because it tells users that I'm reading their browsing history. And it's just scary. Opt-in and optional permission "tabs" is something that I want to avoid because the "default" behavior is always the king, and has the highest usage.
What I've tried:
"chrome-extension//", "chrome-extension", "chrome-extension///" in manifest.json permissions. It always results in an error like this "Permission 'chrome-extension//' is unknown or URL pattern is malformed".
Script in of the newtab.html page with window.chrome.runtime.sendMessage to inform the background script it's a new tab that was opened. It's not fast enough. chrome.tabs.onCreated.addListener fires much faster.
Meta tag with redirect to the newtab.html hosted somewhere online. Works nice, but this feature has to be an opt-out.
ManifestV2: use chrome.extension.getViews
background.js:
chrome.tabs.onCreated.addListener(tab => {
const onUpdated = (tabId, info, updatedTab) => {
if (tabId === tab.id && info.status && chrome.extension.getViews({tabId})[0]) {
chrome.tabs.onUpdated.removeListener(onUpdated);
console.log('My newtab', updatedTab);
// doSomething(tab);
}
};
chrome.tabs.onUpdated.addListener(onUpdated);
});
ManifestV3: use fetch event:
background.js:
let isOpeningMyTab;
self.onfetch = e => {
// assuming your page is chrome-extension://**id**/newtab.html
if (e.request.url.startsWith(location.origin + '/newtab.html')) {
isOpeningMyTab = true;
setTimeout(() => { isOpeningMyTab = false; });
}
};
chrome.tabs.onCreated.addListener(tab => {
if (isOpeningMyTab) {
console.log('My newtab', tab);
// doSomething(tab);
}
});

How can I open a tab without loading it in a Google Chrome extension?

The only thing I could think of was using chrome.tabs.discard, and below is my current code:
var test_button= document.getElementById('test_button');
test_button.onclick = function(element) {
var to_load = {"url": "https://stackoverflow.com", "active": false, "selected": false};
chrome.tabs.create(to_load, function(tab) {
chrome.tabs.discard(tab.id);
});
};
However, rather than preventing this page from loading, calling chrome.tabs.discard before it's loaded results in Chrome replacing it with about:blank.
The only "solution" I found was to wait for the tab to load, but waiting for it to load before unloading it defeats the purpose, especially if I'm opening a large amount of tabs at once.
Any help would be appreciated.
The solution is to only call chrome.tabs.discard on the tab after its URL value has updated, such as:
var tabs_to_unload = {}
chrome.tabs.onUpdated.addListener(function(tabId, changeInfo, changedTab) {
if (tabs_to_unload[tabId] == true) {
// We can only discard the tab once its URL is updated, otherwise it's replaced with about:empty
if(changeInfo.url) {
chrome.tabs.discard(tabId);
delete tabs_to_unload[tabId];
}
}
});
var test_button= document.getElementById('test_button');
test_button.onclick = function(element) {
var to_load = {"url": "https://stackoverflow.com", "active": false, "selected": false};
chrome.tabs.create(to_load, function(tab) {
tabs_to_unload[tab.id] = true;
});
};
In my case, the exact code was a bit different, as I was performing these actions from within a popup, and the variables and listeners registered by its script only lived as long as the popup, but the principle behind it was the same.

chrome-extention replace the selected text

I m trying to port my firefox plugin to chrome and here is my sample code.
File: myscript.js (partial)
.
.
function init() {
.
.
.
}
function myFunc(inp, option) {
.
.
.
}
chrome.extension.onMessage.addListener(function (message, sender, response) {
switch (message) {
case "ITRANS":
console.log("ITRANS");
if (document.getSelection().baseNode != null){
init();
window.modifySelection(myFunc(window.getSelection().toString(), 0));
}
break;
case "Devanagari":
console.log("Devanagari");
if (document.getSelection().baseNode != null){
init();
window.modifySelection(myFunc(window.getSelection().toString(), 1));
}
break;
default:
console.log("Default");
}
});
File: background.js
var _selection_univ = chrome.contextMenus.create({
"title": "INDIC 2 ITRANS",
"id": "ITRANS",
"onclick": reportclick,
"contexts": ["selection"]
}, function () {
console.log("Context Menu 1 ITRANS");
});
var _selection_univ = chrome.contextMenus.create({
"title": "Eng 2 Devanagari",
"id": "Devanagari",
"onclick": reportclick,
"contexts": ["selection"]
}, function () {
console.log("Context Menu 2 Devanagari");
});
function reportclick(info, tab) {
switch (info.menuItemId) {
case "ITRANS":
console.log("BG: ITRANS");
chrome.tabs.sendMessage(tab.id, "ITRANS");
break;
case "Devanagari":
console.log("BG: Devanagari");
chrome.tabs.sendMessage(tab.id, "Devanagari");
break;
default:
console.log("BG: Default");
}
}
File: manifest.json
{
"name": "Parivartan",
"version": "0.8.2",
"manifest_version": 2,
"permissions":[
"contextMenus",
"<all_urls>",
"tabs"
],
"content_scripts": [
{
"matches": ["<all_urls>"],
"js": ["myscript.js"],
"all_frames": true
}
],
"background": {
"scripts": ["background.js"]
}
}
I am not able to figure out few things.
(1) Where should my init() function (which should run only once to inititialize my plugin globals) be placed.
(2) Replace the selected text with the output of a function.
The above code does not work says "modifySelection" not found.
(3) How can call my functions if they are in a different (file2.js) file.
At present I placed all my functions in a single file (myscript.js).
(4) How can I create menu within a menu.
I tried to search on google but could not find solutions to the above. Can anyone please help me.
-Mohan
(1) Where should my init() function (which should run only once to inititialize my plugin globals) be placed ?
Depending on your requirements there are two events that should cover your initialization needs:
chrome.runtime.onInstalled:
Fired when the extension is first installed, when the extension is updated to a new version, and when Chrome is updated to a new version.
E.g.: chrome.runtime.onInstalled.addListener(function() {...});
chrome.runtime.onStartup:
Fired when a profile that has this extension installed first starts up. This event is not fired when an incognito profile is started, even if this extension is operating in 'split' incognito mode.
E.g.: chrome.runtime.onStartup.addListener(function(details) {...});
(2) Replace the selected text with the output of a function. The above code does not work says "modifySelection" not found.
That is because the function modifySelection is not defined. Where did you get that name ?
UPDATE:
Based on OP's feedback in comments, a simple modifySelection() function could look like this:
function modifySelection(newValue) {
var range = document.getSelection().getRangeAt(0);
range.deleteContents();
range.insertNode(document.createTextNode(newValue));
}
(Note: It will only work properly if the selection involves TextNodes only. In other cases it might break the DOM, so more detailed parsing of the selection is required.)
(3) How can call my functions if they are in a different (file2.js) file. At present I placed all my functions in a single file (myscript.js).
You inject all the necessary files and then you call the functions as usual. I.e. all injected content scripts are executed in the same JS context. E.g.:
"content_scripts": [{
"matches": ["<all_urls>"],
"js": ["file1.js", "file2.js", ...],
"all_frames": true
}],
In file1.js:
...
function funcInFile1() {...}
...
In file2.js:
...
var res = funcInFile1();
...
(Note: Content scripts are injected in the order in which they appear in the "js" array. Make sure each resource is available before calling it. E.g. trying to call funcInFile1() before injecting file1.js will result in error.)
(4) How can I create menu within a menu.
If by that you mean "create a submenu", there is an parentId attribute that you can include in the createProperties argument of the chrome.contextMenus.create function:
parentId:
The ID of a parent menu item; this makes the item a child of a previously added item.
See, also, this demo extension which does (among other things) exactly that.
Some final remarks
chrome.extension.onMessage is deprecated. Please, use chrome.runtime.onMessage instead.
Try using Event Pages (instead of background pages) when possible.

Website Message Box by Automating InternetExplorer with VBA Excel

I am in the process of automating a process to fill up a website. With an Excel Macro, once I log into the website, insert a value in the required textbox and click the button, a website Message Box comes up with an alert asking me to confirm - Are you sure to update the value?
The execution of the macro stops at that level, resulting in no further execution of the macro.
On searching for the solution, I found out that a JavaScript function, the function which is executed on confirmation of the message box, should be called from macro instead of clicking the original button on the webpage.
I would like to have help in writing the code to call JavaScript function in Excel Macro.
Following is the HTML code from the view source page of the webpage.
$('#reloadButton').click(function () {
$(this).text(
$(this).attr('name')
).attr('disabled', 'disabled');
window.location.href = window.location.href.replace(/#.*$/, '');
});
SignalConsumer = function () {};
SignalConsumer.prototype = new TraderSettingsTool();
SignalConsumer.prototype.mySummaryPage = 'https://kvinvest.com/month/?action=template&tid=my_status';
SignalConsumer.prototype.isShowWaiver = 0;
SignalConsumer.prototype.amountPrecision = 1;
SignalConsumer.prototype._elements = {
"trading": {
"popup": $('#ssc-trading-popup'),
"amount": $('#ssc-trading-amount'),
"trade": $('#ssc-trading-trade'),
"provides": $('#ssc-trading-provides')
},
"slippage": {
"popup": $('#ssc-slippage-popup')
},
"provider": {
"popup": $('#ssc-provider-popup')
},
"consumers":{
"holder": $('#ssc-consumers-holder'),
"template": $('#ssc-consumers-template'),
"form": $('#ssc-consumers-form')
},
"subscribe": {
"server": $('#ssc-subscribe-server'),
"apply": $('#ssc-subscribe-apply'),
"loader": $('#ssc-subscribe-loader'),
"info": $('#ssc-subscribe-info'),
"form": $('#ssc-subscribe-form'),
"description": $('#ssc-subscribe-description')
},
"activate": {
"form": $('#ssc-activate-form'),
"slippage": $('#ssc-activate-slippage'),
"amount": $('#ssc-activate-amount'),
"popup": $('#ssc-activate-popup'),
"apply": $('#ssc-activate-apply'),
"cancel": $('#ssc-activate-cancel'),
"agree": $('#ssc-activate-agree'),
"sll": $('#ssc-activate-sll-value'),
"loader": $('#ssc-activate-sll-loader'),
"redirect": $('#ssc-activate-redirect')
},
"waiver": {
"popup": $('#ssc-waiver-popup'),
"agree": $('#ssc-waiver-agree'),
"apply": $('#ssc-waiver-apply'),
"subscribe": $('#ssc-waiver-subscribe')
},
"history": {
"log": $('#ssc-history-log')
}
};
SignalConsumer.prototype.bindEvents = function () {
var self = this;
this._elements.subscribe.form.find('form').submit(function () {
return false;
});
// I THINK BELOW IS THE MESSAGE BOX POP UP
this._elements.subscribe.apply.click(function () {
if(!confirm('Are you sure to update?')){
return false;
}
self.subscribeToServer();
return false;
});
// On show history popup
this._elements.history.log.click(function () {
self.loadHistoryLog();
return false;
});
// --- ACTIVATION LOGIC ---
this._elements.activate.apply.click(function () {
self.applyActivateServer();
return false;
});
this._elements.activate.agree.change(function () {
var disabled = $(this).is(':checked') ? '' : 'disabled';
self._elements.activate.apply.attr('disabled', disabled);
});
this._elements.activate.cancel.click(function () {
self.hidePopUp();
return false;
});
this._elements.activate.redirect.click(function () {
self.hidePopUp();
});
Well, what I won't do in this answer is provide the code that you request.
This answer is more like a suggestion since I'm not entirely sure about where you are going with this and if the technical approach that you suggest is what you are actually looking for.
It doesn't make a lot of sense to me, to connect the VBA engine with a web client unless you're aiming at retrieval of data only - such as for example a web query.
If you want to create an interactive data flow between the VBA engine and a web application, it seems more logical to create a connection with a server side script (written in PHP or ASP) that is connected to a database system (or if you want to store values in temporary session variables for that matter).
The fact that a user inputs a value, followed by a button click suggests that you want to build in a certain calculation logic. This is typically done on the server, and not browser level.
Therefore what I suggest you do is:
Javascript/jQuery -> PHP/ASP -> VBA
If that makes any sense to you.

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