Using both activeTab and serial permissions - google-chrome-extension

I am trying to use a hardware serial device to change what displays on a webpage in Chrome. I'm making a Chrome extension to do so, however it seems as if I cannot use both the activeTab and serial permissions at the same time. The activeTab permission requires the app to not be a packaged app, and the serial permission requires the app to be packaged.
How can I get around this if possible?
I am using the page redder sample code as the way to change the webpage, however it requires the activeTab permission. Maybe there is a workaround to this? Thanks

The only way I can think of is to create one Chrome Extension and one Chrome App that communicates to each other: https://developer.chrome.com/extensions/messaging#external
// The ID of the extension we want to talk to.
var laserExtensionId = "abcdefghijklmnoabcdefhijklmnoabc";
// Make a simple request:
chrome.runtime.sendMessage(laserExtensionId, {getTargetData: true},
function(response) {
if (targetInRange(response.targetData))
chrome.runtime.sendMessage(laserExtensionId, {activateLasers: true});
});
// Start a long-running conversation:
var port = chrome.runtime.connect(laserExtensionId);
port.postMessage(...);

An alternative is to make a Native Messaging host that communicates with the device and with your extension.
From architectural point of view this makes more sense, but limits your deployment options, as the host program can't be bundled with the extension in the Web Store.

Related

How to open app in the Enterprise Browser?

I have a website with a payment link like this: sumupmerchant://pay/1.0?affiliate-key=aa&app-id=bb&total=0&currency=EUR&title=cc and when i open this URL in Google Chrome on my android device, it opens the app which is installed on the device. The Enterprise Browser doesn't open it (it shows a webpage not available error). Is there anyone who knows if it's possible to open another app from within the enterprise browser?
If it was possible to use the Chrome browser then i would but it's not possible since we have a webapp which needs this browser to make a connection with a Zebra printer.
Thank you in advance.
Pim
Is this Zebra's Enterprise Browser? If so, although you can't open apps by clicking on links there is an Intent API available and you could say something like this:
<script type="text/javascript" charset="utf-8" src="ebapi-modules.js"></script>
var params = {
intentType: EB.Intent.START_ACTIVITY,
action: 'pay',
appName: 'com.company.sumupmerchant',
data: {"afilliate_key":"aa", "app-id":"bb","total":"0","currency":"EUR","title":"cc"}
EB.Intent.send(params);
I'm not sure exactly how to launch your app via Intent, the above is just a guess. More on the Intent API at https://techdocs.zebra.com/enterprise-browser/2-5/api/Intent/

Chrome extension - Notification

How I can send a notification for everyone that has installed my extension?
I'm using new Notification(...) but the notification is just sending for me.
Thank you for all
You will want to use the new gcm service for Push Notifications via Google Cloud Messaging Service.
Here is a tutorial on Google's Chrome Developer page.
Well, this requires a lot of work already done in the extension to be able to do that without updating the extension.
For instance, your extension can periodically look for new notices on your website.
If you need more urgency, you either need to keep WebSocket connections to your server or use some manner of push services, like gcm API that Max Worg just mentioned.
That said, to use all this you need to have the support already in place in your extension.
Okay, but suppose you don't have that support, or don't need it that often.
The usual way to do it is with an extension update, where you add a message for the users and increment a variable with the "release notes" version, so that it will only be shown once. A good idea is to use chrome.storage.sync for this, so that the user won't be annoyed multiple times.
var message = "Sup user, check this out!";
var message_version = 4; // Update this when you want to show a new one
chrome.storage.sync.get(
{message_version: 0}, // Provide default
function(data) {
if(data.message_version < message_version) {
notify(message); // TODO: implement notify()
// Alternatively, open a page with the notice with chrome.tabs.create()
chrome.storage.sync.set({message_version: message_version});
}
}
);
You can see a real-life example here (using a hybrid of localStorage and chrome.storage).

Using getUSerMedia AND webkitSpeechRecognition allow access x 2

I am creating a site that uses two types of audio input... getUserMedia and webkitSpeechRecognition. Both functions are working fine but Chrome is popping up it's access security pop-up twice - which makes sense. Does anyone know how to have one access permission handle both functions?
Cheers SO!
navigator.getUserMedia({audio:true}, gotStream, function(e) {
alert('Error getting audio');
console.log(e);
});
and...
var recognition = new webkitSpeechRecognition();
The only way to avoid asking for permissions multiple times is to make sure that your web page is using the https url. Then Chrome will remember your permissions and not show the pop-up again.
On Chrome 36 (and possibly earlier ones) I'm getting just one popup bar for both.

chrome extension - alternative to externally_connectable?

It seems like the externally_connectable feature that allows a website to communicate with an extension is still in the dev channel and not yet stable. Are there any other ways to allow a specific website to communicate with my extension, while I wait for this feature to become stable? How have chrome extension developers traditionally done it?
Thanks Rob W for pointing me in the direction of HTML5 messaging. For the benefit of other chrome extension developers, I'm writing about the general problem I was trying to solve and the solution that worked in the end.
I am making a chrome extension that can control music playback on a tab via a popup player. When a user clicks on play/pause/etc on the popup player, the extension should be able to convey that message to the webpage and get back a response stating whether the action was accomplished.
My first approach was to inject a content script into the music player page. The problem is, though, that content scripts operate in a "sandbox" and cannot access native javascript on the page. Therefore, the content script was pretty useless (on its own), because while it could receive commands from the extension, it could not effect any change on the webpage itself.
One thing that worked in my favor was that the website where the music was playing belongs to me, so I could put whatever javascript I wanted there and have it be served from the server. That's exactly what I used to my advantage: I created another javascript file that would reside on the website and communicate with the content script mentioned above, via the window object of the page (i.e. HTML5 messaging). This only works because the content script and the javascript file both exist in the same webpage and can share the window object of the page. Thanks Rob W for pointing me to this capability. Here is an example of how the javascript file on the page can initiate a connection with the content script via the window object:
content_script.js (injected by extension into xyz.com):
window.addEventListener("message", function(event) {
if(event.data.secret_key &&
(event.data.secret_key === "my_secret_key") &&
event.data.source === "page"){
if(event.data.type){
switch(event.data.type) {
case 'init':
console.log("received connection request from page");
window.postMessage({source: "content_script", type: 'init',
secret_key: "my_secret_key"}, "*");
break;
}
}
}
}, false);
onpage.js (resides on server and served along with xyz.com):
window.postMessage({source: "page", type: 'init',
secret_key: "my_secret_key"}, "*");
window.addEventListener("message", function(event) {
if(event.data.secret_key &&
(event.data.secret_key === "my_secret_key") &&
event.data.source === "content_script"){
if(event.data.type){
switch(event.data.type) {
case 'init':
console.log("connection established");
break;
}
}
}
}, false);
I check the secret key just to make sure that the message originates from where I expect it to.
That's it! If anything is unclear, or if you have any questions, feel free to follow up!
You could have an extension inject a content script alongside a web page, and use that to pass messages back and forth between the website and the background page of the extension.
It's tedious, though, and externally connectable is a lot nicer.

How do I call SignalR in a chrome extension background page for specific host?

I'm trying to use SignalR in a chrome extension on a background page.
Everything seems to work fine until it tries to call negotiate. It seems to be taking the caller (which is a chrome-extension background page) and trying to call negotiate against that, which gives me a 404 while trying to call this page:
chrome-extension://edcdcfjmmmchhgmomfemdkomibeoloko/signalr/negotiate?_=1372007788595
I'd imagine that it should be calling
https://myserver.com/signalr/negotiate?_=1372007788595
But I don't know how to override SignalR with a specific host. Can I override SignalR to work in a chrome extension on a background page
I assume it is javascript you are using? Try
$.connection.hub.url = "http://myserver.com/signalr";
This took me a couple hours to figure out but here's a few steps to get going on making signalr work with a google chrome extension.
Place within the javascript
$.connection.hub.url = "http://yoursever.com/signalr"`
Within the manifest.json file for the google chrome you must give permission to access the server. I would add something like this to make it easy.
"permissions": [
"http://*/*",
"https://*/*"
]
Within your global configuration you need to change allow cross domain requests. Change
RouteTable.Routes.MapHubs()
to
RouteTable.Routes.MapHubs(new HubConfiguration()
{
EnableCrossDomain = true
});

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