My question is different from the other posts similar to this.
AutoCAD offers developers a means of displaying a URL page inside the application. I created an intranet site for my company with the hopes that users can explore via desktop browser or their AutoCAD application.
The problem is that the browser AutoCAD uses is Chrome version 33 (currently its at 84) - there is no way to update or change the browser either.
I have no way to "inspect" or debug the site inside AutoCAD - and I've come to find out there are many difference in v84 and v33. I'm trying to diagnose errors right now but again, I have no way of accessing the console logs inside the AutoCAD Browser.
Is there a way for me to "alert" any errors that the console is trying to give me? (ie: the page can't find a script reference, there is an unexpected '.', etc...)
NOTE - my site runs great on the most updated Chrome browser (v84 on desktop browser), but some little things are not working right in v33 (in AutoCAD Browser).
If you control the website you can attach a listener on the window to listen for any unhandled exceptions. Add this before all other scripts to make sure everything is captured.
window.on('error', (e) => {
// if error is intresting, do work.
alert(e.message);
});
The handler accepts an ErrorEvent object.
NOTE - This will not capture errors that are triggered in scripts across domain. For example if you are loading google maps, and an error is triggered within that script, you will typically get a 'Script error.' and no other info. This has to do with cross origin policies. You can read more here.
If you need to specifically to capture data sent to console.error you can simply proxy the function. This may not capture anything except for code that explicitly calls console.error and is not recommended.
const error = console.error;
console.error = (...args) => {
// alert(...);
error.apply(console, args);
}
Related
The error in the title is caught by Sentry (an error tracking tool). Below is a screenshot from Sentry - showing the stack trace.
Note: the script /en_US/iab.autofill.payment.js where handleMessage is located is loaded from Facebook (link here), and I couldn't find this script in the javascript bundle, nor anything related to it. I assume it's loaded by a 3rd party script - I'm using Google Tag Manager (which is also loading Facebook Pixel), Segment (loading Hotjar and Mixpanel), and Snapchat. The error started to appear without any changes in these scripts or the services that they're sending data to.
Note 2: It seems that the error is triggered quite often, about 10-15% of the time. I tried to reproduce it but given that it's a handled error, it doesn't show in the dev console.
Any direction on where to look would be much appreciated.
I'm seeing this a lot, and it seems to be coming 100% from users using Facebook browser on iOS (I guess this is the browser you see when you're using the Facebook app).
I tried to debug this with a snippet:
<script>
window.addEventListener('message', function (e) {
console.log(e);
JSON.parse(e.data);
console.log('foo');
}, false);
</script>
This is from the library you linked. Assuming that e.data is JSON string (not e.g. an object?), without any safeguard seems to be breaking things.
The second console.log doesn't fire, so I think this is causing some unexpected behaviours in my case (buttons not reacting to clicks with js listeners etc)
I don't know if there is a workaround or a way to protect from this in Facebook embedded browser (I guess it's loaded there)
Looking forward to hear more info
i have meet that too, its because the one script facebook inject in. will postMessage(Object), but the another script will listen the message and try to JSON.parse an object ,so it will came out a error. u can use 'vconsole' lib, and add a window.addEventListener('message',(e)=>{console.log(e.data)}) and u can see that
Apparently, the issue went away after a couple of weeks without changing anything on my side.
Firefox Web Console offers a screenshot helper function:
:screenshot --selector '#element-id' --dpr 1
Probably a silly question, but is it possible to call this function from JavaScript at my website? Say, I have some button and it calls this:
function downloadScreenshot()
{
if(navigator.userAgent.toLowerCase().indexOf('firefox') === -1)
{ alert("Firefox-only"); return; }
eval(":screenshot --selector '#element-id' --dpr 1");
}
If I try to run this I naturally get SyntaxError: expected expression, got ':'.
So is there some way to call Firefox Web Console API (or whatever) from JS and "tell" it to execute the screenshot command?
Firefox Developer Edition 63.0b10 (64-bit).
I reckon, it is not possible. One of the reasons would be that "malicious" scripts at websites could spam your disc with screenshots taken every millisecond.
You can't. Those helper functions are executed in a totally different context then a web page, with totally different privileges. Here the source code: https://searchfox.org/mozilla-central/source/devtools/shared/screenshot/save.js
So from a web page, you don't have access to them.
The only way to have a similar functionality, is create your own add-on that take the screenshot. Then, from your website, you can check if the add-on is installed, and send to it the command to take the screenshot.
I'm working on a project that involves retrieving multiple websites with PhantomJS and when I try to load Amazon.com, PhantomJS crashes while trying to evaluate this function with the error:
TypeError: 'undefined' is not a function (evaluating 'window.ueLogError')
The weird thing is that I can't seem to find any documentation or explanation of any kind for window.ueLogError. A google search gives a handful of websites with scripts that contain it, but it doesn't seem to be a part of any documentation I can find. Does anyone know anything about ueLogError?
The window object is the global sink in the browser. Every variable that you define globally (e.g. jQuery's $) is a property in window. ueLogError is not some kind of standardized JavaScript function. It is most likely some function for an advertisement script.
Not all resources that a page requests as part of the page load are actually successfully loaded. Some requests fail due to SSL problems. Some requests fail, because the user agent string is not supported. Some requests fail because of unknown reasons.
You can register to the onConsoleMessage, onError, onResourceError, onResourceTimeout events (Example) to see whether there are errors. Usually you will find that some JavaScript file wasn't loaded which would have contained ueLogError which another script depends on.
We have a web application which runs in a kiosk mode Firefox, using the RKiosk extension to achieve this. We suspect that we have a very rare error in the system which yields in a JavaScript error. However because we can't access the JavaScript console we can't examine the log.
I'm searching for an option to make Firefox log all JavaScript console messages into a file regardless of the tab and page opened. I can't seem to find any extension for this. I'm already using log4javascript which sends errors back to the server, but it seems that our application crashes in a way that it skips the logging altogether.
Writing to a file sounds like a tedious task to me. It requires privileges that browser code doesn't normally have and you'd have to negotiate with an add-on you'd have to write in order to access file I/O.
From what I understand your issue is
I'd like to make Firefox log all errors
There are several approaches we can do to tackle this
First approach - log everything to localStorage too:
Now, rather than writing to an actual file, you can write to localStorage or IndexedDB instead.
localStorage["myApplog"] = localStorage["myApplog"] || "";
var oldLog = console.log;
console.log = function(){
oldLog.apply(console,arguments); // use the old console log
var message = "\n "+(new Date).toISOString() + " :: "+
Array.prototype.join.call(arguments," , "); // the arguments
localStorage["myApplog"] += message;
}
This is rather dirty and rather slow, but it should get the job done and you can access the log later in local storage. LocalStorage has a ~5MB limit if I recall correctly which I think is enough if you don't go crazy with logging. You can also run it selectively.
Second approach - log only errors
This is similar to what Pumbaa80 suggested. You can simply override window.onerror and only log errors.
// put an empty string in loggedWinErrors first
var oldError = window.onerror || function(){};
window.onerror = function(err,url,lineNumber){
oldError.call(this,err,url,lineNumber);
var err ="\n Error: (file: " + url+", error: "+err+", lineNumber: "+lineNumber+")");
localStorage["loggedWinErrors"] += err;
}
Third and drastic approach - use a VM.
This is the most powerful version, but it provides the most problematic user experience. You run the kiosk in a virtual machine, you detect an uncaught exception - when you do you freeze the machine and save its state, and run a backup VM instead. I've only had to do this when tackling the most fearsome errors and it's not pretty. Unless you really want the whole captured state - don't do this.
Really, do the extension before this - this is tedious but it gets very solid results.
In conclusion, I think the first approach or even just the second one are more than enough for what you need. localStorage is an abstracted storage that web pages get for saving state without security issues. If that's not big enough we can talk about an IndexedDB solution.
It all really depends on the use case you have.
You can use XULRunner...a Mozilla runtime environment for XUL applications. It uses Gecko like Firefox and:
You can access the file system or using the SQLite database to store logs.
You can render your kiosk in fullscreen mode without using extensions.
Have you tried jserrorcollector? We are using it and it works fine (only in Firefox). It's only for Java.
// Initialize
FirefoxProfile ffProfile = null;
ffProfile = new FirefoxProfile();
JavaScriptError.addExtension(ffProfile);
// Get the errors
List<JavaScriptError> jsErrors = JavaScriptError.readErrors(webDriver);
More information: https://github.com/mguillem/JSErrorCollector
Have you considered remote logging?
I commonly assign window.onerror to do send a request to a webserver storing the details of the error remotely. You could do the same with console.log if you preferred.
Try the following console export. It is a plugin for Firebug of Firefox. It's quite handy.
http://www.softwareishard.com/blog/consoleexport/
If you are able/willing to switch from Firefox to Chrome or Opera you would be able to use the Sandboxed Filesystem API to write a local file. See:
http://www.html5rocks.com/en/tutorials/file/filesystem/
http://caniuse.com/filesystem
Start in kiosk mode using chrome.exe --kiosk <url>
You would then want to disable Alt-F4 and Ctrl-Alt-Del which on Windows can be done with several third-party tools like Auto Hotkey (Disable Ctrl-Alt-Del Script).
You could use a remote logging script like Qbaka. It catches every JS error and sends it to the Qbaka server. There you can login and see all JS errors. Qbaka stores the exact error message, the script, line number, stack trace and the used browser for each error message.
I'm capturing js errors in the application with window.onerror, but the thing is - in Chrome if dev tools isn't opened - then the url parameter passed to onerror handler always equals to the opened url.
While if dev tools is opened - then the url points to the exact .js file the caused the js error.
How do you deal with it? Are there any workarounds?
And to be more clear - here are 2 results:
Uncaught ReferenceError: a is not defined index:122 - this was received after fetching a page
Uncaught ReferenceError: a is not defined List.js:122 - this was received after fetching the same page with dev tools opened. This is an expected result - I've put a(); call to the List.js file for testing.
UPD: this is done for functional testing (using selenium webdriver) - I want to capture js errors for further investigations.
Let's pose the following architecture:
window.addEventListener("error", handleException, false);
function handleException(I_sMsg) {
if (I_sMsg.stack) {
sMsg = I_sMsg.stack.replaceAll(getBaseURL(), "");
alert(sMsg);
} else if (I_sMsg.message) {
alert(I_sMsg.message);
}
return cancelEvent(I_sMsg);
}
Now any throw new Error("description"); will go through the first part of the if statement and have a nice stack for you to parse with the urls.
It also works for unexpected exceptions, having as a result the following message (in this case after calling the unexisting bibi() function)
After further investigation, my framework is using some kind of home made job management (as shown in the stack actually) where every single action belongs to a job.
The job execution method is the following (simplified)
try {
oTask.func.apply(oTask.obj, oTask.prms);
} catch(ex) {
handleException(ex);
return false;
}
So it means every single execution is encapsulated within this single try catch block. As you see, the exception is caught, and passed to the handler. Not the error.
I though it was working in the other file but it was because the call was encapsulated, while within the api.js file directly it was a free call not managed by the framework.
More of a something to try answer really but it might help.
Chrome recently added chrome://inspect/ to the list of handy URLs (see chrome://chrome-urls/ for the complete list). I cannot find the tweet or blog post I read about this unfortunately but I think it was within the last month. The URL works on Chrome 28 for sure.
chrome://inspect/ lists all open tabs with an inspect link which redirects back to the existing open page but also opens DevTools.
I'm thinking that the selenium test could open the site under test in one tab and in a second tab open the inspect page, follow the inspect link back to the test page but this time with DevTools open, allowing window.onerror to capture better errors.
Something like:
document.getElementsByClassName('row')[n].getElementsByTagName('a')[0].click()