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.
Related
So I'm trying to read out a USB-scale thats connected to my pc. I use chrome's experimental HID api.
I use Tampermonekey as userscript injector to extend a website's functionality.
The script I inject looks like this:
navigator.hid.requestDevice({ filters: [{ vendorId: 0x0922, productId: 0x8003}] }).then((devices) => {
if (devices.length == 0) return;
devices[0].open().then(() => {
if(disconnected) {
disconnected = false
}
console.log("Opened device: " + devices[0].productName);
devices[0].addEventListener("inputreport", handleInputReport);
devices[0].sendReport(outputReportId, outputReport).then(() => {
console.log("Sent output report " + outputReportId);
});
});
});
When I run it just like this(inline) I get the message in chrome:
DOMException: Failed to execute 'requestDevice' on 'HID': Must be handling a user gesture to show a permission request.
Basically, the code needs to be inside an event listener and the listener needs to be triggered by user input to run.
Al fine and dandy, except that this has to be initialized hundreds of times a day. I tried running this code in edge and here it just works without user input.
Is there a way I can disable this security feature(completely or only for the site im using it on) in chrome? I know edge is based on chromium so I expect it to be possible, but am unable to find how/where
You can use HID.getDevices() to retrieve an HID device that the user has already granted access to.
My suggestion would be to check for the device you want with getDevices first. If you can't find the device, then make something the user can interact with that will allow you to use requestDevice to connect to the device.
Im trying to read NFC tags from chrome 81 on andriod with the following code:
<html>
<head>
<title>NFC</title>
</head>
<body>
<button onclick="reader()">Scan</button>
<script>
function reader(){
const reader = new NDEFReader();
reader.scan().then(() => {
alert("Scan started successfully.");
reader.onerror = () => {
alert("Cannot read data from the NFC tag. Try another one?");
};
reader.onreading = event => {
alert("NDEF message read.");
};
}).catch(error => {
alert(`Error! Scan failed to start: ${error}.`);
});
}
</script>
</body>
the problem im having with it is that it reads the entry from the nfc tag but doesnt give alerts like the code suggests, instead it trys to direct me to installed apps on my phone. However, when i use https://googlechrome.github.io/samples/web-nfc/ that is using the full API it works and displays in the webpage as data. The main difference is that im using the Enabling via chrome://flags method to allow the NFC API.
out of reading the tag, my only aim is to save the content to sessionStorage as a variable to be used by other parts of the website.
Thanks in advance
One difference between https://googlechrome.github.io/samples/web-nfc/ and your code that would matter is the fact this demo used to have an origin trial token in its web page.
For now, to experiment with Web NFC on Android, enable the #experimental-web-platform-features flag in chrome://flags as described in https://web.dev/nfc/#use
Hopefully this flag won't be required once it is shipped to the web platform.
I have this problem where in firefox the speech gets cut off if the page is auto-refreshed, but in google chrome it finishes saying the speech even if the page is auto-refreshed. How do I fix it so that the speech doesn't get cut off in firefox even when the page is auto-refreshed?
msg = new SpeechSynthesisUtterance("please finish saying this entire sentence.");
window.speechSynthesis.speak(msg);
(function ($) {
'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!
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
I am a WP dev beginner and learning how to write a simple video recorder app. I am using javascript and HTML on VS Pro 2013 and debugging on my actual device Lumia 520 (running Windows Phone 8.1 Preview). I read through a body of documentations and found that the MediaCapture class was the core class for this purpose. So I started following some tutorials and wrote up some functions to access the camera and display a preview in a HTML5 video tag. However, I wasn't successful in getting the MediaCapture object initialized, not even displaying the preview. Below are the major functions of which the first one was problematic:
function initCapture() {
findRearFacingCamera().then(function (cameraId) {
try {
if (cameraId != null && cameraId != "") {
// Initialize the settings
captureInitSettings = null;
captureInitSettings = new Windows.Media.Capture.MediaCaptureInitializationSettings();
captureInitSettings.videoDeviceId = cameraId;
captureInitSettings.streamingCaptureMode = Windows.Media.Capture.StreamingCaptureMode.video;
captureInitSettings.photoCaptureSource = Windows.Media.Capture.PhotoCaptureSource.videoPreview;
captureInitSettings.realTimeModeEnabled = true;
// Initialize the capture
oMediaCapture = null;
oMediaCapture = new Windows.Media.Capture.MediaCapture();
oMediaCapture.initializeAsync(captureInitSettings).then(preview, errorHandler);
}
} catch (e) { }
});
}
function preview() {
var preview = document.getElementById("PreviewScreen");
preview.msZoom = true;
if (preview != null) {
preview.src = URL.createObjectURL(oMediaCapture);
preview.play();
}
}
function errorHandler(e) {
var information = document.getElementById("message");
information.innerHTML = e.message;
}
During debugging, I paused at the statement oMediaCapture = new Windows.Media.Capture.MediaCapture(); in the initCapture() function. At this point, captureInitSettings.videoDeviceId has the value: "\\?\DISPLAY#QCOM_AVStream#3&25691128&0&UID32768#{e5323777-f976-4f5b-9b55-b94699c46e44}\Back Sensor", which I believed was a correct identification of the rear camera that I intended to use. Then, when I continued with a break point set at var preview = document.getElementById("PreviewScreen"); in function preview(), which was supposed to be called upon successful initialization of the MediaCapture object, the program was trapped into the errorHandler() function instead, with the error message being "Access is denied" with error number "-2147024891". So I guess the problem rose from the .initializeAsync() function, which was unsuccessful. Deeper causes might also be related to the permission to access the camera. BTW, I have enabled the webcam and microphone capabilities for this app, which was not the issue.
I believe I was missing something either in the code or in the big picture of the development settings. Please help me identify the issue and let me know if any additional information is needed. Much appreciated!
Did you make sure you added the Rear Camera requirement in your Package Manifest?
Turned out the problem was really with my device. Recall that I was testing on a Lumia 520 with Windows Phone 8.1 preview, the firmware stayed at Lumia Black. After upgrading the firmware to Lumia Cyan (parallel to Windows Phone 8.1) using the Nokia Recovery Software Tool, the problem disappeared.