HTML5 Notification not working in Mobile Chrome - javascript

I'm using the HTML5 notification API to notify the user in Chrome or Firefox. On desktop browsers, it works. However in Chrome 42 for Android, the permission is requested but the notification itself is not displayed.
The request code, works on all devices:
if ('Notification' in window) {
Notification.requestPermission();
}
The sending code, works on desktop browser but not on mobile:
if ('Notification' in window) {
new Notification('Notify you');
}

Try the following:
navigator.serviceWorker.register('sw.js');
Notification.requestPermission(function(result) {
if (result === 'granted') {
navigator.serviceWorker.ready.then(function(registration) {
registration.showNotification('Notification with ServiceWorker');
});
}
});
That is, use ServiceWorkerRegistration»showNotification() not new Notification().
That should work on Android both in Chrome and in Firefox — and on iOS in Safari, too.
(The sw.js file can just be a zero-byte file.)
One caveat is that you must run it from a secure origin (an https URL, not an http URL).
See https://developer.mozilla.org/docs/Web/API/ServiceWorkerRegistration/showNotification.

If you already have a service worker registered, use this:
navigator.serviceWorker.getRegistrations().then(function(registrations) {
registrations[0].showNotification(title, options);
});

Running this code:
if ('Notification' in window) {
Notification.requestPermission();
}
Console in Chrome DevTools shows this error:
Uncaught TypeError: Failed to construct ‘Notification’: Illegal
constructor. Use ServiceWorkerRegistration.showNotification() instead
A better approach might be:
function isNewNotificationSupported() {
if (!window.Notification || !Notification.requestPermission)
return false;
if (Notification.permission == 'granted')
throw new Error('You must only call this \*before\* calling
Notification.requestPermission(), otherwise this feature detect would bug the
user with an actual notification!');
try {
new Notification('');
} catch (e) {
if (e.name == 'TypeError')
return false;
}
return true;
}
Function Source: HTML5Rocks

I had no trouble with the Notification API on Windows Desktop. It even worked without issues on Mobile FF. I found documentation that seemed to indicate Chrome for Android was supported too, but it didn't work for me. I really wanted to prove the API could work for me on my current (2019) version of Chrome (70) for Android. After much investigation, I can easily see why many people have had mixed results. The answer above simply didn't work for me when I pasted it into a barebones page, but I discovered why. According to the Chrome debugger, the Notification API is only allowed in response to a user gesture. That means that you can't simply invoke the notification when the document loads. Rather, you have to invoke the code in response to user interactivity like a click.
So, here is a barebones and complete solution proving that you can get notifications to work on current (2019) Chrome for Android (Note: I used jQuery simply for brevity):
<html>
<head>
<script type="text/javascript" src="libs/jquery/jquery-1.12.4.min.js"></script>
<script>
$( function()
{
navigator.serviceWorker.register('sw.js');
$( "#mynotify" ).click( function()
{
Notification.requestPermission().then( function( permission )
{
if ( permission != "granted" )
{
alert( "Notification failed!" );
return;
}
navigator.serviceWorker.ready.then( function( registration )
{
registration.showNotification( "Hello world", { body:"Here is the body!" } );
} );
} );
} );
} );
</script>
</head>
<body>
<input id="mynotify" type="button" value="Trigger Notification" />
</body>
</html>
In summary, the important things to know about notifications on current (2019) Chrome for Android:
Must be using HTTPS
Must use Notification API in response to user interactivity
Must use Notification API to request permission for notifications
Must use ServiceWorker API to trigger the actual notification

new Notification('your arguments'); This way of creating notification is only supported on desktop browsers, not on mobile browsers. According to the link below. (scroll down to the compatibility part)
https://developer.mozilla.org/en-US/docs/Web/API/Notifications_API/Using_the_Notifications_API
For mobile browsers below is the way you create a notification (this also works on desktop browsers)
navigator.serviceWorker.ready.then( reg => { reg.showNotification("your arguments goes here")});
Tested on browsers using webkit engine.
For more information please visit below links:
https://developers.google.com/web/updates/2015/05/notifying-you-of-changes-to-notifications
https://developers.google.com/web/fundamentals/push-notifications/display-a-notification

Related

JavaScript dialogs alert(), confirm() and prompt() in cross origin iframe does not work any longer

Apps script web app works in <iframe>. It seems Chrome is no longer supporting alert(), confirm(), Promote these functions on the web app.
Any workaround to this?
Chrome Version 92.0.4515.107 (Official Build) (64-bit) -- does not work
Edge Version 91.0.864.71 (Official build) (64-bit) -- works
Tried replacing alert() with window.alert(), but still does not work.
exec:1 A different origin subframe tried to create a JavaScript dialog. This is no longer allowed and was blocked. See https://www.chromestatus.com/feature/5148698084376576 for more details.
This is absurd and subjective decision of Google to remove alert(), confirm(), and prompt() for cross origin iframes. And they called it "feature". And justification is very poor - see "motivation" bellow. A very weak reason for removing such an important feature! Community and developers should protest!
Problem
https://www.chromestatus.com/feature/5148698084376576
Feature: Remove alert(), confirm(), and prompt for cross origin iframes
Chrome allows iframes to trigger Javascript dialogs, it shows “ says ...” when the iframe is the same origin as the top frame, and “An embedded page on this page says...” when the iframe is cross-origin. The current UX is confusing, and has previously led to spoofs where sites pretend the message comes from Chrome or a different website. Removing support for cross origin iframes’ ability to trigger the UI will prevent this kind of spoofing, and unblock further UI simplifications.
Motivation
The current UI for JS dialogs (in general, not just for the cross-origin subframe case) is confusing, because the message looks like the browser’s own UI. This has led to spoofs (particularly with window.prompt) where sites pretend that a particular message is coming from Chrome (e.g. 1,2,3). Chrome mitigates these spoofs by prefacing the message with “ says...”. However, when these alerts are coming from a cross-origin iframe, the UI is even more confusing because Chrome tries to explain the dialog is not coming from the browser itself or the top level page. Given the low usage of cross-origin iframe JS dialogs, the fact that when JS dialogs are used they are generally not required for the site’s primary functionality, and the difficulty in explaining reliably where the dialog is coming from, we propose removing JS dialogs for cross-origin iframes. This will also unblock our ability to further simplify the dialog by removing the hostname indication and making the dialog more obviously a part of the page (and not the browser) by moving it to the center of the content area. These changes are blocked on removing cross-origin support for JS dialogs, since otherwise these subframes could pretend their dialog is coming from the parent page.
Solution
Send message via Window.postMessage() from iframe to parent and show dialog via parent page. It is very elegant hack and shame on Google because before Chrome version 92 client saw alert dialog e.g. An embedded page iframe.com" says: ... (which was correct - client see real domain which invoked alert) but now with postMessage solution client will see a lie e.g. The page example.com" says: ... but alert was not invoked by example.com. Stupid google decision caused them to achieve the opposite effect - client will be much more confused now. Google's decision was hasty and they didn't think about the consequences. In case of prompt() and confirm() it is a little bit tricky via Window.postMessage() because we need to send result from top back to iframe.
What Google will do next? Disable Window.postMessage()? Déjà vu. We are back in Internet Explorer era... developers waste time by doing stupid hacks.
TL;DR: Demo
https://domain-a.netlify.app/parent.html
Code
With code bellow you can use overridden native alert(), confirm() and prompt() in cross origin iframe with minimum code change. There is no change for alert() usage. I case of confirm() and prompt() just add "await" keyword before it or feel free to use callback way in case you can not switch easily your sync functions to async functions. See all usage examples in iframe.html bellow.
Everything bad comes with something good - now I gained with this solution an advantage that iframe domain is not revealed (domain from address bar is now used in dialogs).
https://example-a.com/parent.html
<!doctype html>
<html>
<head>
<meta charset="utf-8">
<title>Parent (domain A)</title>
<script type="text/javascript" src="dialogs.js"></script>
</head>
<body>
<h1>Parent (domain A)</h1>
<iframe src="https://example-b.com/iframe.html">
</body>
</html>
https://example-b.com/iframe.html
<!doctype html>
<html>
<head>
<meta charset="utf-8">
<title>Iframe (domain B)</title>
<script type="text/javascript" src="dialogs.js"></script>
</head>
<body>
<h1>Iframe (domain B)</h1>
<script type="text/javascript">
alert('alert() forwarded from iframe.html');
confirm('confirm() forwarded from iframe.html via callback', (result) => {
console.log('confirm() result via callback: ', result);
});
prompt('prompt() forwarded from iframe.html via callback', null, (result) => {
console.log('prompt() result via callback: ', result);
});
(async () => {
var result1 = await confirm('confirm() forwarded from iframe.html via promise');
console.log('confirm() result via promise: ', result1);
var result2 = await prompt('prompt() forwarded from iframe.html via promise');
console.log('prompt() result via promise: ', result2);
})();
</script>
</body>
</html>
dialogs.js
(function() {
var id = 1,
store = {},
isIframe = (window === window.parent || window.opener) ? false : true;
// Send message
var sendMessage = function(windowToSend, data) {
windowToSend.postMessage(JSON.stringify(data), '*');
};
// Helper for overridden confirm() and prompt()
var processInteractiveDialog = function(data, callback) {
sendMessage(parent, data);
if (callback)
store[data.id] = callback;
else
return new Promise(resolve => { store[data.id] = resolve; })
};
// Override native dialog functions
if (isIframe) {
// alert()
window.alert = function(message) {
var data = { event : 'dialog', type : 'alert', message : message };
sendMessage(parent, data);
};
// confirm()
window.confirm = function(message, callback) {
var data = { event : 'dialog', type : 'confirm', id : id++, message : message };
return processInteractiveDialog(data, callback);
};
// prompt()
window.prompt = function(message, value, callback) {
var data = { event : 'dialog', type : 'prompt', id : id++, message : message, value : value || '' };
return processInteractiveDialog(data, callback);
};
}
// Listen to messages
window.addEventListener('message', function(event) {
try {
var data = JSON.parse(event.data);
}
catch (error) {
return;
}
if (!data || typeof data != 'object')
return;
if (data.event != 'dialog' || !data.type)
return;
// Initial message from iframe to parent
if (!isIframe) {
// alert()
if (data.type == 'alert')
alert(data.message)
// confirm()
else if (data.type == 'confirm') {
var data = { event : 'dialog', type : 'confirm', id : data.id, result : confirm(data.message) };
sendMessage(event.source, data);
}
// prompt()
else if (data.type == 'prompt') {
var data = { event : 'dialog', type : 'prompt', id : data.id, result : prompt(data.message, data.value) };
sendMessage(event.source, data);
}
}
// Response message from parent to iframe
else {
// confirm()
if (data.type == 'confirm') {
store[data.id](data.result);
delete store[data.id];
}
// prompt()
else if (data.type == 'prompt') {
store[data.id](data.result);
delete store[data.id];
}
}
}, false);
})();
File a feature request:
Consider filing a feature request using this Issue Tracker template.
I'd either request that an exception is made for Apps Script web apps, or that built-in methods for alert and confirm are added, similar to the existing alert and prompt dialogs, which currently work on Google editors.
Bug filed:
By the way, this behavior has been reported in Issue Tracker (as a bug):
Javascript in html files doesn't work
I'd consider starring it in order to keep track of it.
Workaround:
In the meanwhile, as others said, consider downgrading or changing the browser, or executing it with the following command line flag:
--disable-features="SuppressDifferentOriginSubframeJSDialogs"
Related question:
Chrome SuppressDifferentOriginSubframeJSDialogs setting override using JS?
So far, the only 'solution' for this is to add the following to your Chrome/Edge browser shortcut:
--disable-features="SuppressDifferentOriginSubframeJSDialogs"
Or downgrade your browser. Obviously neither of these are ideal. Google trying really hard to save us from ourselves here.

How do you obtain permissions from web-nfc API?

I'm trying to get Web NFC to work through the Web NFC API, but I can't get it past an error message of NotAllowedError: NFC permission request denied.
I'm using this on Chrome 89 Dev on a Windows 10 computer, and the source code is being run locally.
I have tried the examples posted on the Internet also, including the Google sample but it returns the same error. I'm not concerned with it being experimental at this point as referring to this does show it has successfully passed the necessary tests, including permissions.
The HTML/JS code I'm using is below, and I've read the specification point 9.3, but I can't make sense of it to write it as code, so is there a guideline algorithm that would be helpful here to resolve this?
async function readTag() {
if ("NDEFReader" in window) {
const reader = new NDEFReader();
try {
await reader.scan();
reader.onreading = event => {
const decoder = new TextDecoder();
for (const record of event.message.records) {
consoleLog("Record type: " + record.recordType);
consoleLog("MIME type: " + record.mediaType);
consoleLog("=== data ===\n" + decoder.decode(record.data));
}
}
} catch(error) {
consoleLog(error);
}
} else {
consoleLog("Web NFC is not supported.");
}
}
async function writeTag() {
if ("NDEFWriter" in window) {
const writer = new NDEFWriter();
try {
await writer.write("helloworld");
consoleLog("NDEF message written!");
} catch(error) {
consoleLog(error);
}
} else {
consoleLog("Web NFC is not supported.");
}
}
function consoleLog(data) {
var logElement = document.getElementById('log');
logElement.innerHTML += data + '\n';
};
<!DOCTYPE html>
<html>
<head>
<script src="webnfc.js"></script>
</head>
<body>
<p>
<button onclick="readTag()">Test NFC Read</button>
<button onclick="writeTag()">Test NFC Write</button>
</p>
<pre id="log"></pre>
</body>
</html>
From https://web.dev/nfc/#security-and-permissions
Web NFC is only available to top-level frames and secure browsing contexts (HTTPS only). Origins must first request the "nfc" permission while handling a user gesture (e.g a button click). The NDEFReader scan() and write() methods trigger a user prompt, if access was not previously granted.
I guess you are running from a file:// URL as you said "locally" which is not supported.
You need to host it from a local web server using a https:// URL
Once in the right scope trying to scan or write should trigger a user prompt.
You can also check permissions see https://web.dev/nfc/#check-for-permission
Update:
So I tried the sample page https://googlechrome.github.io/samples/web-nfc/
And this works for me on Android Chrome 87 with "Experimental Web Platform features" enabled
When you hit the scan button A dialog asking for permission pops up.
Comparing the code in this sample to yours I notice that does:-
ndef.addEventListener("reading" , ({ message, serialNumber }) => { ...
Where as yours does:-
ndef.onreading = event => { ...
I don't know if it is the style setting what happens on the Event or something else (Hey this is all experimental)
Update2
To answer the question from the comments of Desktop support.
So you should be some of the desktop/browser combinations at the moment and may be in the future there will be wider support as this is no longer experimental standards. Obviously as your test link suggest Chrome on a Linux Desktop should work as this is really similar to Android Support, with all the NFC device handling done by libnfc and the browser just has to know about this library instead of every type usb or other device than can do NFC.
From what seen of NFC support on Windows, most of this is focussed on direct controlling the NFC reader via USB as just another USB device, while there is a libnfc equivalent in Windows.Networking.Proximity API's I've not come across any NFC reader saying they support this or anybody using it.
For Mac Deskstop, given that Apple are behind the curve with NFC support in iOS, I feel their desktop support will be even further behind even though it could be similar to Linux.
As you can read at https://web.dev/nfc/#browser-support, Web NFC only supports Android for now which is why you get "NotAllowedError: NFC permission request denied." error on Windows.

Why reCAPTCHA doesnt work in actual Chrome?

I was developing a site on a local server (Open Server) with a built-in Google Chrome browser version 68.0.3440.106. Captcha v2 is connected to forms, but on more modern versions of the same browser I get the error Uncaught (in promise) null on anchor: 1. I don’t understand what the problem is, and how to solve it.
Here is my code:
"use strict";
var idCaptcha1;
var onloadReCaptchaInvisible = function () {
try {
//login
idCaptcha1 = grecaptcha.render('recaptcha1', {
"sitekey": "mycaptchakey",
"callback": "onSubmitReCaptcha1",
"size": "invisible"
});
} catch (e) {
//nothing
}
}
function onSubmitReCaptcha1(token) {
sendForm('signin', idCaptcha1);
}
So its working fine in old browser, when I want to send ajax form, it trigger captcha and user can work with it. What I did wrong? Except didnt update browser of local server of course ><

Speech gets cut off in firefox when page is auto-refreshed but not in google chrome

I have this problem where in firefox the speech gets cut off if the page is auto-refreshed, but in google chrome it finishes saying the speech even if the page is auto-refreshed. How do I fix it so that the speech doesn't get cut off in firefox even when the page is auto-refreshed?
msg = new SpeechSynthesisUtterance("please finish saying this entire sentence.");
window.speechSynthesis.speak(msg);
(function ($) {
'use strict';
if (window == window.top) {
var body = $('body').empty();
var myframe = $('<iframe>')
.attr({ src: location.href })
.css({ height: '95vh', width: '100%' })
.appendTo(body)
.on('load', function () {
var interval;
interval = 750;
setTimeout(function () {
myframe.attr({ src: location.href });
}, interval);
});
}
})(jQuery);
I have this problem where in firefox the speech gets cut off if the
page is auto-refreshed, but in google chrome it finishes saying the
speech even if the page is auto-refreshed.
The described behaviour for Firefox is a sane expected implementation.
Browsing the source code of Firefox and Chromium the implementation of speechSynthesis.speak() is based on a socket connection with the local speech server. That server at *nix is usually speech-dispatcher or speechd (speech-dispatcher). See How to programmatically send a unix socket command to a system server autospawned by browser or convert JavaScript to C++ souce code for Chromium? for description of trying to implement SSML parsing at Chromium.
Eventually decided to write own code to achieve that requirement using JavaScript according to the W3C specification SpeechSynthesisSSMLParser after asking more than one question at SE sites, filing issues and bugs and posting on W3C mailings lists without any evidence that SSML parsing would ever be included as part of the Web Speech API.
Once that connection is initiated a queue is created for calls to .speak(). Even when the connection is closed Task Manager might still show the active process registered by the service.
The process at Chromium/Chrome is not without bugs, the closest that have filed to what is being described at the question is
Issue 797624: "speak speak slash" is audio output of .speak() following two calls to .speak(), .pause() and .resume()
Why hasn't Issue 88072 and Issue 795371 been answered? Are Internals>SpeechSynthesis and Blink>Speech dead? (for possible reason why "but in google chrome it finishes saying the speech even if the page is auto-refreshed." is still possible at Chrome)
.volume property issues
Issue 797512: Setting SpeechSynthesisUtterance.volume does not change volume of audio output of speechSynthesis.speak() (Chromium/Chrome)
Bug 1426978 Setting SpeechSynthesisUtterance.volume does not change volume of audio output of speechSynthesis.speak() (Firefox)
The most egregious issue being Chromium/Chrome webkitSpeechReconition implementation which records the users' audio and posts that audio data to a remote service, where a transcript is returned to the browser - without explicitly notifying the user that is taking place, marked WONT FIX
Issue 816095: Does webkitSpeechRecognition send recorded audio to a remote web service by default?
Relevant W3C Speech API issues at GitHub
The UA should be able to disallow speak() from autoplaying #27
Precisely define when speak() should fail due to autoplay rules #35 (ironically, relevant to the reported behaviour at Chromium/Chrome and output described at this question, see Web Audio, Autoplay Policy and Games and Autoplay Policy Changes)
Intent to Deprecate: speechSynthesis.speak without user activation
Summary
The SpeechSynthesis API is actively being abused on the web. We don’t have hard data on abuse, but since other autoplay avenues are
starting to be closed, abuse is anecdotally moving to the Web Speech
API, which doesn't follow autoplay rules.
After deprecation, the plan is to cause speechSynthesis.speak to
immediately fire an error if specific autoplay rules are not
satisfied. This will align it with other audio APIs in Chrome.
Timing of SpeechSynthesis state changes not defined #39
Timing of SpeechSynthesisUtterance events firing not defined #40
Clarify what happens if two windows try to speak #47
In summary, would not describe the behaviour at Firefox as a "problem", but the behaviour at Chrome as being a potential "problem".
Diving in to W3C Web Speech API implementation at browsers is not a trivial task. For several reasons. Including the apparent focus, or available option of, commercial TTS/SST services and proprietary, closed-source implementations of speech synthesis and speech recognition in "smart phones"; in lieu of fixing the various issues with the actual deployment of the W3C Web Speech API at modern browsers.
The maintainers of speechd (speech-dispatcher) are very helpful with regards to the server side (local speech-dispatcher socket).
Cannot speak for Firefox maintainers. Would estimate it is unlikely that if a bug is filed relevant to the feature request of continuing execution of audio output by .speak() from reloaded window is consistent with recent autoplay policies implemented by browsers. Though you can still file a Firefox bug to ask if audio output (from any API or interface) is expected to continue during reload of the current window; and if there are any preferences or policies which can be set to override the described behaviour, as suggested at the answer by #zip. And get the answer from the implementers themselves.
There are individuals and groups that compose FOSS code which are active in the domain and willing to help SST/TTS development, many of which are active at GitHub, which is another option to ask questions about how to implement what you are trying to achieve specifically at Firefox browser.
Outside of asking implementers for the feature request, you can read the source code and try create one or more workarounds. Alternatives include using meSpeak.js, though that still does not necessarily address if Firefox is intentionally blocking audio output during reload of the window.
Not sure why there's a difference in behavior... guest271314 might be on to something in his answer. However, you may be able to prevent FF from stopping the tts by intercepting the reload event with a onbeforeunload handler and waiting for the utterance to finish:
msg = new SpeechSynthesisUtterance("say something");
window.speechSynthesis.speak(msg);
window.onbeforeunload = function(e) {
if(window.speechSynthesis.speaking){
event.preventDefault();
msg.addEventListener('end', function(event) {
//logic to continue unload here
});
}
};
EDITED: See more elegant solution with promises below initial answer!
Below snippet is a workaround to the browser inconsistencies found in Firefox, checking synth.speaking in the interval and only triggering a reload if it's false prevents the synth from cutting of prematurely:
(It does not NOT work properly in the SO snippet, I assume it doesn't like iFrames in iFrames or whatever, just copy paste the code in a file and open it with Firefox!)
<p>I'm in the body, but will be in an iFrame</p>
<script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/3.3.1/jquery.min.js"></script>
<script>
var synth = window.speechSynthesis;
msg = new SpeechSynthesisUtterance("please finish saying this entire sentence.");
synth.speak(msg);
(function ($) {
'use strict';
if (window == window.top) {
var body = $('body').empty();
var myframe = $('<iframe>')
.attr({ src: location.href })
.css({ height: '95vh', width: '100%' })
.appendTo(body)
.on('load', function () {
var interval;
interval = setInterval(function () {
if (!synth.speaking) {
myframe.attr({ src: location.href });
clearInterval(interval);
}
}, 750);
});
}
})(jQuery);
</script>
A more elaborate solution could be to not have any setTimeout() or setInterval() at all, but use promises instead. Like this the page will simply reload whenever the message is done synthesizing, no matter how short or long it is. This will also prevent the "double"/overlapping-speech on the initial pageload. Not sure if this helps in your scenario, but here you go:
<button id="toggleSpeech">Stop Speaking!</button>
<script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/3.3.1/jquery.min.js"></script>
<script>
if (window == window.top) {
window.speech = {
say: function(msg) {
return new Promise(function(resolve, reject) {
if (!SpeechSynthesisUtterance) {
reject('Web Speech API is not supported');
}
var utterance = new SpeechSynthesisUtterance(msg);
utterance.addEventListener('end', function() {
resolve();
});
utterance.addEventListener('error', function(event) {
reject('An error has occurred while speaking: ' + event.error);
});
window.speechSynthesis.speak(utterance);
});
},
speak: true,
};
}
(function($) {
'use strict';
if (window == window.top) {
var body = $('body').empty();
var myframe = $('<iframe>')
.attr({ src: location.href })
.css({ height: '95vh', width: '100%' })
.appendTo(body)
.on('load', function () {
var $iframe = $(this).contents();
$iframe.find('#toggleSpeech').on('click', function(e) {
console.log('speaking will stop when the last sentence is done...');
window.speech.speak = !window.speech.speak;
});
window.speech.say('please finish saying this entire sentence.')
.then(function() {
if ( window.speech.speak ) {
console.log('speaking done, reloading iframe!');
myframe.attr({ src: location.href });
}
});
});
}
})(jQuery);
</script>
NOTE: Chrome (since v70) does NOT allow the immediate calling of window.speechSynthesis.speak(new SpeechSynthesisUtterance(msg)) anymore, you will get an error speechSynthesis.speak() without user activation is no longer allowed..., more details here. So technically the user would have to activate the script in Chrome to make it work!
Firefox:
First of all type and search for the “about: config” inside the browser by filling it in the address bar. This will take to another page where there will be a pop up asking to Take Any Risk, you need to accept that. Look for the preference named “accessibility.blockautorefresh” from the list and then right-click over that. There will be some options appearing as the list on the screen, select the Toggle option and then set it to True rather than False. This change will block the Auto Refresh on the Firefox browser. Remember that this option is revertable!

Use the HTML5 web MIDI API

I'm trying to make a simple synth web-app using the web audio API and I want to use it with my MIDI keyboard through the web MIDI API, so I tried these instructions both on Chrome and Chrome Canary but always I get the "navigator.getMIDIAccess is not a function" error, the version is 40 for Chrome and 42 for Chrome Canary, both on Mac OS X (10.10.2) and the experimental flag has been enabled.
The code for now is very simple (this is a test):
<script type="text/javascript">
try{
//navigator.getMIDIAccess = ( navigator.getMIDIAccess || navigator.webkitGetMIDIAccess || navigator.mozGetMIDIAccess || navigator.msGetMIDIAccess);
navigator.getMIDIAccess(_event_success, function(){
alert("ERROR");
});
}catch(ex){
console.log(ex);
alert("NOT SUPPORTED");
}
function _event_success(){
console.log("OK");
}
</script>
Where is the error?
If may be helpful I'm using a M-AUDIO Keystation88 keyboard on USB.
Is Chrome the only one that suport this feature?
The api call is "requestMIDIAccess". (It is not prefixed.)

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