When using Lib-GDX html, how can I know when the SoundManager crashes. It sometimes crashes because of flash errors and I would like to reload my website when that happens.
It turns out it is pretty simple, all you have to do is setup a listener and wait for the alert to appear. I do not know if this has any other dangerous consequences, but this was bugging me and I found a solution, I want to make sure future users know about it.
function check() {
var node = document.getElementById('embed-html'),
htmlContent = node.innerHTML;
if(htmlContent.includes("canvas")){
document.getElementById('logodiv').style.display = 'none';
}else if(htmlContent.includes("gwt-TextArea gwt-TextArea-readonly")){
window.location.reload();
}
and put that in a timeout:
setTimeout(check, 100);
Related
I'm trying to build something using the processor node here. Almost anything I do in terms of debugging it crashes chrome. Specifically the tab. Whenever I bring up dev tools, and 100% of the time i put a breakpoint in the onaudioprocess node, the tab dies and I have to either find the chrome helper process for that tab or force quit chrome altogether to get started agin. Its basically crippled my development for the time being. Is this a known issue? Do I need to take certain precautions to prevent chrome from crashing? Are the real time aspects are the web audio api simply not debuggable?
Without seeing your code, it's a bit hard to diagnose the problem.
Does running this code snippet crash your browser tab?
let audioCtx = new (window.AudioContext || window.webkitAudioContext)();
function onPlay() {
let scriptProcessor = audioCtx.createScriptProcessor(4096, 2, 2);
scriptProcessor.onaudioprocess = onAudioProcess;
scriptProcessor.connect(audioCtx.destination);
let oscillator = audioCtx.createOscillator();
oscillator.type = "sawtooth";
oscillator.frequency.value = 220;
oscillator.connect(scriptProcessor);
oscillator.start();
}
function onAudioProcess(event) {
let { inputBuffer, outputBuffer } = event;
for (let channel = 0; channel < outputBuffer.numberOfChannels; channel++) {
let inputData = inputBuffer.getChannelData(channel);
let outputData = outputBuffer.getChannelData(channel);
for (let sample = 0; sample < inputBuffer.length; sample++) {
outputData[sample] = inputData[sample];
// Add white noise to oscillator.
outputData[sample] += ((Math.random() * 2) - 1) * 0.2;
// Un-comment the following line to crash the browser tab.
// console.log(sample);
}
}
}
<button type="button" onclick="onPlay()">Play</button>
If it crashes, there's something else in your local dev environment causing you problems, because it runs perfectly for me.
If not, then maybe you are doing a console.log() (or some other heavy operation) in your onaudioprocess event handler? Remember, this event handler processes thousands of audio samples every time it is called, so you need to be careful what you do with it. For example, try un-commenting the console.log() line in the code snippet above – your browser tab will crash.
Is it possible to tell if another Chrome tab is using webkitSpeechRecognition?
If you try to use webkitSpeechRecognition while another tab is using it, it will throw an error "aborted" without any message. I want to be able to know if webkitSpeechRecognition is open in another tab, and if so, throw a better error that could notify the user.
Unless your customer is on the same website(you could check by logging the ip/browserprint in database and requesting by json) you cannot do that.
Cross domain protection is in effect, and that lets you know zilch about what happens in other tabs or frames.
I am using webkitSpeechRecognition for chrome ( does not work on FF) and I faced same issues like multiple Chrome tabs. Until the browser implement a better error message a temporary solutions that work for me:
You need to detect when a tab is focused or not in Chrome using
Javascript.
Make javascript code like this
isChromium = window.chrome;
if(isChromium)
{
if (window.addEventListener)
{
// bind focus event
window.addEventListener("focus", function (event)
{
console.log("Browser tab focus..");
recognition.stop();// to avoid error
recognition.start();
}, false);
window.addEventListener("blur", function (event)
{
console.log("Browser tab blur..");
recognition.stop();
}, false);
}
}
There's a small workaround for it. You can store the timestamp in a variable upon activating SpeechRecognition and when it exits after a few seconds of inactivity, it will be compared to a timestamp since the SpeechRecognition was activated. Since two tabs are using the API simultaneously, it will exit immediately.
For Chrome, you can use the code below and modify it base on your needs. Firefox doesn't support this yet at the moment.
var transcriptionStartTime;
var timeSinceLastStart;
function configureRecognition(){
var webkitSpeechRecognition = window.webkitSpeechRecognition || window.SpeechRecognition;
if ('webkitSpeechRecognition' in window) {
recognition = new webkitSpeechRecognition();
recognition.continuous = true;
recognition.interimResults = true;
recognition.lang = "en-US";
recognition.onend = function() {
timeSinceLastStart = new Date().getTime() - transcriptionStartTime;
if (timeSinceLastStart < 100) {
alert('Speech recognition failed to start. Please close the tab that is currently using it.');
}
}
}
}
See browser compatibility here: https://developer.mozilla.org/en-US/docs/Web/API/SpeechRecognition
I am just making IRC in actionscript 3, but now i have a little problem with Socket. Connections are fine, but i get disconnect when i don't replay ping back, so my question is how can i create pong in AS3? I did search for some tutorials, but i cant find all and some explains isnt fine to understand. If anyone can help me on good way.
Thanks!
So far as i am:
var servername:String = "irc.example.com";
var portnumber:int = 6667;
var _sock:Socket = new Socket();
_sock.addEventListener(Event.CONNECT, onConnect);
_sock.addEventListener(ProgressEvent.SOCKET_DATA, onSocketData);
_sock.connect(servername, portnumber);
function onConnect(evt:Event):void {
tServerInfo.text = "Verbinden met " + servername;
}
function onSocketData(event:ProgressEvent):void {
var socketdata:String;
while(_sock.bytesAvailable) {
socketdata = _sock.readUTFBytes(_sock.bytesAvailable);
tServerInfo.text = socketdata;
}
}
Ping, or keep-alive messages aren't anything special; they're just normal messages, sent on a schedule. You just need to set up a Timer to send a ping message (can be anything) every, say 15 seconds or so, in order to keep the Socket open, otherwise it'll close down as it's not being used.
You also need a small bit of code to ignore these messages when you're reading them, but it's trivial.
I have a Widget that I created and I am embedding it on other websites using an iFrame. What I want to do is make sure no one can view the source and copy the iFrame code and put it on their own website.
I can store the URL that it should be allowed on in the database. I've seen it done before, one site had a long encrypted code and if it didn't match with the domain then it said Access Denied..
Does anyone know how I can do this?
Thanks!
No you can't do this. The best thing you can do is the following:
if (window.top.location.host != "hostname") {
document.body.innerHTML = "Access Denied";
}
Add the above to your JavaScript and then use a JavaSript obfuscator
You cannot prevent people from looking at your HTML, but there are some headers can allow you to specify what sites can embed your iframe. Take a look at the X-Frame-Options header and the frame-ancestors directive of Content-Security-Policy. Browsers that respect it will refuse to load the iframe when embedded into someone else's site.
On the server in the code for the page displayed in the IFRAME, check the value of the Referer header. Unless this header has been blocked for privacy reasons, it contains the URL of the page which hosts the IFRAME.
What you are asking for is pretty much impossible. If you make the source available on the web someone can copy it one way or another. Any javascript tricks can be defeated by using low level tools like wget or curl.
So even if you protect it, you're still going to find that someone could in theory copy the code (as the browser would receive it) and could if so determined put it on their own website.
I faced the same problem, but I return the user on a home page. I spread the decision.
It has to be placed where there is iframe
<script>
$(window).load(function () {
var timetoEnd = '';
var dstHost = 'YOUR-ALLOW-HOST';
var backToUrl = 'BACK-TO-URL';
function checkHost(){
var win = window.frames.YOUR-IFRAME-NAME;
win.postMessage('checkHost', dstHost);
console.log('msg Sended');
clearInterval(timetoEnd);
timetoEnd = setInterval(function () {
window.location.href = backToUrl;
}, 5000);
}
function validHost(event) {
if (event.data == 'checkHostTrue') {
clearInterval(timetoEnd);
console.log('checkHostTrue');
} else {
return;
}
}
window.addEventListener("message", validHost, false);
checkHost();
setInterval(function () {
checkHost();
}, 10000
);
});
</script>
It has to be placed into your src iframe
<script>
function receiveMessage(event)
{
if(event.data=='checkHost'){
event.source.postMessage("checkHostTrue",
event.origin);
} else {
return;
}
}
window.addEventListener("message", receiveMessage, false);
</script>
I know it's kinda old topic but I have code that you just put in <script> tag and it should prevent most of curious people from looking at html files from iFrame:
if(window.top.location.pathname === window.location.pathname){
history.back()
}
I just started learning WebSockets today. I am using Safari and the following C# as my WebSocket server (http://www.codeproject.com/KB/webservices/c_sharp_web_socket_server.aspx).
My client is as simple as the following:
<script type="text/javascript">
try{
var socket = new WebSocket('ws://localhost:8181');
alert(socket.readyState);
socket.onopen = function() {
alert('opened...');
};
socket.onclose = function() {
alert('closed');
};
socket.onerror = function(){
alert('error!');
}; }
catch(exception){
alert(exception);
}
</script>
On Safari, am getting the message "Closed" which means the event onclose was raised before the onopen(). I suspecting that the server is closing the connection, any idea? Also, what's the best way to investigate issues like this? any error or reason code?
Thanks!
I guess I figured it out. On Safari you can enable Developer Tools and I was getting missing Sec-WebSocket-Origin header so I went ahead and changed the following:
WebSocket-Origin changed to Sec-WebSocket-Origin