I'm trying to connect to a server using websockets. I've set up the port on the server, and am trying to connect through the Dev console in Chrome (also tried Firefox and got the same result).
I connect from the console using:
var websocket = new WebSocket('ws://localhost:5001');
This gives me the message "undefined". However, if I do
websocket.readyState
I get "1".
I then do
websocket.binaryType = 'arraybuffer';
which prints "arraybuffer".
If I then do something like
websocket.send("1+1");
it says undefined.
However, if I do all of this in an HTML file with JavaScript, it connects fine and I get the result "2", so it looks as though the Websocket itself is ok, and what I'm typing in is ok, but it's something to do with it being in the Dev Console that's the issue.
I don't know anything much about setting up Websockets.
I solved this by adding an onmessage function to the websocket:
websocket.onmessage = function (result) {
console.log(result.data);
}
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I'm using VueJS and Laravel for my project. This issue started to show lately and it shows even in the old git branches.
This error only shows in the Chrome browser.
I disabled all installed extensions in Chrome - works for me.
I have now clear console without errors.
In case you're an extension developer who googled your way here trying to stop causing this error:
The issue isn't CORB (as another answer here states) as blocked CORs manifest as warnings like -
Cross-Origin Read Blocking (CORB) blocked cross-origin response
https://www.example.com/example.html with MIME type text/html. See
https://www.chromestatus.com/feature/5629709824032768 for more
details.
The issue is most likely a mishandled async response to runtime.sendMessage. As MDN says:
To send an asynchronous response, there are two options:
return true from the event listener. This keeps the sendResponse
function valid after the listener returns, so you can call it later.
return a Promise from the event listener, and resolve
when you have the response (or reject it in case of an error).
When you send an async response but fail to use either of these mechanisms, the supplied sendResponse argument to sendMessage goes out of scope and the result is exactly as the error message says: your message port (the message-passing apparatus) is closed before the response was received.
Webextension-polyfill authors have already written about it in June 2018.
So bottom line, if you see your extension causing these errors - inspect closely all your onMessage listeners. Some of them probably need to start returning promises (marking them as async should be enough). [Thanks #vdegenne]
If you go to chrome://extensions/, you can just toggle each extension one at a time and see which one is actually triggering the issue.
Once you toggle the extension off, refresh the page where you are seeing the error and wiggle the mouse around, or click. Mouse actions are the things that are throwing errors.
So I was able to pinpoint which extension was actually causing the issue and disable it.
Post is rather old and not closely related to Chrome extensions development, but let it be here.
I had same problem when responding on message in callback. The solution is to return true in background message listener.
Here is simple example of background.js. It responses to any message from popup.js.
chrome.runtime.onMessage.addListener(function(rq, sender, sendResponse) {
// setTimeout to simulate any callback (even from storage.sync)
setTimeout(function() {
sendResponse({status: true});
}, 1);
// return true; // uncomment this line to fix error
});
Here is popup.js, which sends message on popup. You'll get exceptions until you un-comment "return true" line in background.js file.
document.addEventListener("DOMContentLoaded", () => {
chrome.extension.sendMessage({action: "ping"}, function(resp) {
console.log(JSON.stringify(resp));
});
});
manifest.json, just in case :) Pay attention on alarm permissions section!
{
"name": "TestMessages",
"version": "0.1.0",
"manifest_version": 2,
"browser_action": {
"default_popup": "src/popup.html"
},
"background": {
"scripts": ["src/background.js"],
"persistent": false
},
"permissions": [
"alarms"
]
}
To me i was using a VPN extension called
Free VPN for Chrome - VPN Proxy VeePN It was causing the error after disabling it only ... the error disappeared
This error is generally caused by one of your Chrome extensions.
I recommend installing this One-Click Extension Disabler, I use it with the keyboard shortcut COMMAND (⌘) + SHIFT (⇧) + D — to quickly disable/enable all my extensions.
Once the extensions are disabled this error message should go away.
Peace! ✌️
If error reason is extension use incognito Ctrl+Shift+N. In incognito mode Chrome does not have extensions.
UPD. If you need some extension in incognito mode e.g. ReduxDevTools or any other, in extension settings turn on "Allow in incognito"
Make sure you are using the correct syntax.
We should use the sendMessage() method after listening it.
Here is a simple example of contentScript.js It sendRequest to app.js.
contentScript.js
chrome.extension.sendRequest({
title: 'giveSomeTitle', params: paramsToSend
}, function(result) {
// Do Some action
});
app.js
chrome.extension.onRequest.addListener( function(message, sender,
sendResponse) {
if(message.title === 'giveSomeTitle'){
// Do some action with message.params
sendResponse(true);
}
});
For those coming here to debug this error in Chrome 73, one possibility is because Chrome 73 onwards disallows cross-origin requests in content scripts.
More reading:
https://www.chromestatus.com/feature/5629709824032768
https://www.chromium.org/Home/chromium-security/extension-content-script-fetches
This affects many Chrome extension authors, who now need to scramble to fix the extensions because Chrome thinks "Our data shows that most extensions will not be affected by this change."
(it has nothing to do with your app code)
UPDATE: I fixed the CORs issue but I still see this error. I suspect it is Chrome's fault here.
In my case it was a breakpoint set in my own page source. If I removed or disabled the breakpoint then the error would clear up.
The breakpoint was in a moderately complex chunk of rendering code. Other breakpoints in different parts of the page had no such effect. I was not able to work out a simple test case that always trigger this error.
I suggest you first disable all the extensions then one by one enable them until you find the one that has caused the issue in my case Natural Reader Text to Speech was causing this error so I disabled it. nothing to do with Cross-Origin Read Blocking (CORB) unless the error mention Cross-Origin then further up the tread it is worthwhile trying that approach.
I faced the same error in my react project running.
That error coming from my chrome
IObit Surfing Protection
2.2.7
extensions. That extension off my error was solved.
If you face same like that error, 1st turn off your chrome ad blocker or any other extensions while running.
Late here but in my case it was Kaspersky Cloud Protection Extension. I disabled it. It worked all good.
The cause of this issue is related to one of your chrome extensions, not CORS or CORB. To fix that you can turn off each and every chrome extension you installed.
Norton Safe Web extension for chrome is throwing this error message for me. After I disabled this extension, the error message disappeared.
Just cleaning site cookies worked here.
In my case i had to switch off "Adblock extension" from chrome.
I'm an iOS developer who recently started using Socket.IO. During the life cycle of my iOS application, my server will be receiving messages from my app as the client, but for one particular case, the server will also need to receive a message from a web browser as the client. I'm testing a very basic browser UI, which includes a text field and a button and on the tap of that button, a numeric code (which was entered in the text field) needs to be sent to the server. This is what that looks like:
<form>
Code:<br>
<input type="text" id="code" name="code"><br>
<input type="submit" id="validatebutton" value="Validate">
<script src="/socket.io-client/dist/socket.io.js"></script>
<script>
document.getElementById("validatebutton").onclick = function() {
var socket = io('http://localhost:3000');
socket.on('connect', function(clientSocket) {
clientSocket.emit('validateCode', document.getElementById("code"));
});
};
</script>
</form>
The connection works fine. When I run this code, the client successfully connects to the listening socket server. The only problem is that the event handler is not executed. I may be very off here, but what I went for is a client event handler, which is included in the Swift SDK:
self.socket.on(clientEvent: .connect, callback: { (data:[Any], ack:SocketAckEmitter) in
// Do something here
})
self.socket.connect()
I'm just assuming that the Javascript client has a client event handler (named 'connect') as well, which is received by the client at the moment of connecting to a server. Like I said, I may be way off here. I'm just following the Socket.IO documentation posted on their website, which tells me to do it this way. If someone can tell me what I'm missing, or what I'm doing wrong, it would be much appreciated. Sorry for all the noobishness, but I really don't know where else to turn, since the official documentation is very vague and the other question on Stack are a little too advanced for me.
I wouldn't put the emit function inside the connect. Try emitting like below in your client
<script>
var socket = io('http://localhost:3000');
document.getElementById("validatebutton").onclick = function() {
socket.emit('validateCode', document.getElementById("code"));
};
</script>
Your click event was probably getting executed, but the emit was not due to it being wrapped in the connect function (which only gets executed when the socket connects to the server)
Also I would put the JavaScript in its own file, but for now, at least after the form (not inside it) will work.
I have a node.js server running. It accepts messages via socket.IO.
I need to send messages to the server from some device. This device supports Javascript, but does not support socket.IO commands (it's strange, but that's what I have).
I tried to work around it in the following way:
On my server I put a send.html file that sends a socket.IO message:
<script src="https://cdn.socket.io/socket.io-1.2.0.js"></script>
<script>
var socket = io('http://localhost:3000/');
socket.emit('message', 'messages sent');
</script>
If I just call this file (localhost/send.html) then everything works fine.
Then I try to call send.html via ajax from the device:
<script>
var xmlhttp = new XMLHttpRequest();
xmlhttp.open("POST", "http://localhost/send.html", true);
xmlhttp.send();
</script>
and.. nothing happens.
If I try to call any other .html file from the device, then it works. This makes me think that a socket.IO connection cannot be opened by a file that was called by ajax.
However I couldn't find this fact anywhere and anyway, I still need to find a way to send data from the device to socket.IO.
Does anyone know how to solve this problem, or can think of an alternative solution?
I downloaded the red5-recorder (http://www.red5-recorder.com/) , which fails to allow me to start recording. After debugging I found that the netconnection, needed to record to a media server, created does not fire a NetStatusEvent event, so essentially it fails silently. I have implemented the connection with the following minimal working example:
trace("make net connection");
nc = new NetConnection();
nc.client = { onBWDone: function():void{ trace("bandwidth check done.") } };
trace("add event listener");
nc.addEventListener(NetStatusEvent.NET_STATUS, function(event:NetStatusEvent) {
trace("handle");
});
trace("connect!");
nc.connect("rtmp://localshost/oflaDemo/test/");
trace("connect done");
The output of this piece of code is:
make net connection
add event listener
connect!
connect done
The actionscript api states that the connect-call always fires such an event:
http://help.adobe.com/en_US/FlashPlatform/reference/actionscript/3/flash/net/NetConnection.html#includeExamplesSummary
Moreover, the netconnection is not 'connected' (a state of the NetConnection object) 10 seconds after the call. I also took a look at this: NetConnect fails silently in Flash when called from SilverLight But the fix suggested by the author, swapping rtmp and http in the connection uri, do not work. Also, I tested the uri and in fact the exact same code sniplet in a personal project, where it did work. I just can not seem to find why connecting to a media server fails silently in the red5-recorder project.
The awkward part is that if I pass some random string as a conenction uri, still nothing happens (no event, no exception, no crash). Also not setting nc.client becore nc.connect(), which caused exceptions in my experience, did not cause exceptions.
Any suggestions are welcome.
You are setting the address to localshost instead localhost.
nc.connect("rtmp://localshost/oflaDemo/test/");
Correct address:
nc.connect("rtmp://localhost/oflaDemo/test/");