I'm using ImgCache.js within my ionic2 project, recently I upgraded ionic from rc.3 to rc.5 and ImgCache stopped working.
While debugging, I could see that the success and error callbacks in ImgCaches.Init() were never called. So I debugged the ImgCache.js' Init method and was able to find that the method:
navigator.webkitPersistentStorage.requestQuota
Is only calling any callback when the Quota data is bigger than the previous amount (or after I cleaned the cache/cookies), which will ask the user permission to store files in his device.
I tested in canary (version 58.0.2989.0 canary (64-bit)) but this didn't work either.
P.s.: The problematic code is here: https://github.com/chrisben/imgcache.js/blob/master/js/imgcache.js#L622
P.s.2: It's only happening when I set a breakpoint before ImgCache.init()
After a couple hours of debugging, I discovered the problem was actually the debugging. The problem only occured when I set a debugger before ImgCache.init()
Related
I am working in an ember application. The version is "ember-cli": "1.13.13".
For a very strange reason, debugger doesn't work in Chrome. (I also tried Safari, and Firefox developer's edition. Same thing.)
Specifically, the problem is I put a debugger statement in a function. Ember app loads and hits the function and the debugger statement in the function. What happens in the Developer Tools -> Sources tab is that it doesn't show me the function that the debugger is in.
Instead it keeps highlighting the last line of app-boot.js file. The breakpoint, or the line that it's paused on, is not showing up at all. (see screenshot attached)
Furthermore when I step into the function call using the down arrow, it remains at app-boot.js, so I have no idea whether it did step into the function or not.
This has been plaguing me for a while now.
I've resolved many times similar error on OSX + Chrome by using Empty Cache and Hard Reload - after that code in Sources tab was updated and I could correctly see actual source code.
Make sure you didn't blackbox scripts of your application.
Alternatively you could try to reinstall npm packages, bower packages - it might be issue with creating source maps in Ember CLI.
If nothing helps please investigate your JavaScript and associated map files and check if something might be missing, or maps don't update. You could possibly try turning them on and off in Ember CLI.
See Source Maps section in Ember CLI guides how to enable/disable them.
I'm currently (trying) to develop an app with Worklight Studio 5.0.6 and Dojo (Mobile) 1.8.3. I have a really hard time to to find a proper method for debugging. After waiting 5-10 minutes for the build an deploy-process on the server, an error usually looks like this in the Chrome debugger:
How am I supposed to track down this error in MY source? The whole stack trace consists entirely of Dojo code which generates an absolutely useless error message after 20 abstraction layers.
Seriously, how do you guys handle this in real life? What methods do you use for debugging Dojo-driven apps in the browser?
spyro
For dojo.parse errors, I find it useful to pause the Chrome debugger on all exceptions (the purple icon on your screenshot, should be blue). You usally get more details about the cause of the error, the name of the DOM node being parsed, etc. in the first exception being raised.
Rémi.
Debugging dojo based application should be the same as debugging any javascript application.
Usually I will follow these steps:
add console.log() somewhere in code: this is fast and most of time this is enough.
set breakpoint in debugger: if step 1 is not enough, you can base on error information to set breakpoint before error line, then step in or step out.
comment out recently changes: for some error which is hard to find the error line, for example, parse error in your case, the good way is comment out your recently changes one by one till back to your last working version. Or, return to your last working version, then add code back one by one.
Create a simple application to reproduce the error : if your application is very complicate and it is hard for you to follow above methods, you can try to create a new application which mimics your current application but with simple logics and try to reproduce the error.
Based on experience : Some errors, for example, extra ',' in the end of array which works at chrome and firefox, will report a nonsense error information at IE. Debug these kinds of errors is very difficult, you can base on your experience or do a google search.
Did you provide isDebug: true in your dojoConfig? Also, try to see if the same occurs in other browsers.
Update: I recently discovered that there are issues with Google Chrome and Dojo debugging and I think it has to do with the asynchronous loading of files. As you can see in the provided screenshot of #spyro, the ReferenceError object is blank (which you can notice because of the empty brackets {}). If you want to solve that, reopen the console of Google Chrome, (for example by tapping F12 twice). After reopening the ReferenceError should not be empty anymore and now you can expand that object by using the arrow next to it and get a more detailed message about what failed.
Usually what I do in situations like that is to place a breakpoint inside the error callback (line 3398 in your case) and then look into the error variable ("e").
I am not sure how familiar you are with the Web Inspector, but once you hit the breakpoint open the Web Inspector 'console' and check for the error properties "e.message" and "e.stack" (just type in "e.message " in the console).
Also, during development it is better to avoid Dojo optimization / minification, which greatly improve your debug-ability.
Bottom line is to try to place the breakpoint before the error is thrown.
I've tried to run my tests with Selenium 2 and Firefox 19. One of this tests causes an error "ERROR: Command execution failure. The error message is: can't access dead object".
I'm reading about it, it seems like a bug in newest Firefox's versions. Lot of people have the same issue, but I've not found anything really clear.
Any heroe can help us? Maybe we just need to change something in "about:config"?
Regards
I was desperate about the same Problem and didn't find any solution although many people seemed to have the same problem.
I solved it by calling
webDriver.switchTo().defaultContent();
before calling any findElement method
(using Java)
This error generally comes when you do no switch back from frame and trying to access web elements directly.
Use driver.switchTo().defaultContent(); and then try to access the elements
I finally made a "cheat" to the browser.
I got the fail when Selenium clicked on a link and try to open the new page. What I've made is just simulate the click, doing a selenium.open("URL") which replace selenium.click("link=ButtonWhichOpenTheURL").
It seems to work by the moment
I am facing the same error on Firefox 23 while reopening a pop up browser window. The only workaround I did is closing the current selenium session and relaunching it again. It worked fine for me.
This is driving me crazy. I'm working on a C# Forms application that is crashing for some reason when calling _documentList.Items.Clear();. For some reason, Visual Studio never catches the crash and it acts as if the application closed without any errors. I'm in the debugger stepping through line by line, and as soon as I hit the _documentList.Items.Clear();, the debugger stops and the form closes. Please help!
Edit: I've found why the app was crashing, but I'm still not sure why the debugger isn't catching it. This should have been much easier to find than it was.
I was trying to update my GUI from a FileSystemWatcher event, so I had to use this.InvokeRequired and this.Invoke(). I'm no longer getting the crash, but I would still like to know why VS isn't catching this in the debugger. My understanding is I should have been getting an exception with the message "Cross-thread operation not valid:"
I think we don't have listbox.Clear() it shopuld be listbox.Items.Clear();
Have you checked if the listbox have items before stepping into the line where you are clearing the items.
Check the items count of listbox.
It appears that this is a known issue and has been fixed when using Tasks in .NET 4.0. See this question (InvokeRequired Exception Handling) for more info.
I am using a dedicated test SL web application that hosts SL object I am debugging.
I am debugging using basic F5 and use browser Google Chrome. Sometimes a bug happens, how I reproduce it.
I was running build->debug like 100 times already, but then I made a mistake that caused StackOverflowException and happened in main page constructor and afterwards when I rebuild and hit F5 it says no symbols have been loaded. Note that NOTHING has changed , I use the same 2 buttons combinations rebuild solution-> start debugging.
In order for debug to continue to attach I need to close XAML main page , open it again (in visual stuido) and hit rebuild ->f5 again, afterwards it works fine. (found this solution after SOME time)
I am not sure whats bugged but it appears to be a bug somewhere in SL to me.
Question is - whats going on maybe someone can explain.
This sounds more like Chrome's isolation mode for plug-ins. Generally speaking it's best to manually attach to the Chrome process that is running Silverlight (which isn't always one VS attaches to when pressing F5).
Actually error was super simple, I wasn't understanding how "exactly" xap works, it was a little more magical to me than it is. I just needed to rebuild & clear cache in browser ( chrome in this case) to attach successfully. For some reason I thought that local version doesn't require clear cache call.
Actually chrome is pretty bad to debug silverlight so I recommend IE for this sole purpose, sometimes debugger simply fails to attach to chrome, in that case you usually need to do this by attach to process - choose chrome with silverlight name there.