I am developing a portal using ASP.NET MVC plus AngularJS. Everything is working as expected. However, intermittently during development, when I refresh the page, I just see the angular expressions as below (in both chrome and IE 9).
I initially thought it to be a caching issue, and have disabled caching using $httpProvider as suggested here.
Any idea what is the root cause for this behaviour and how to resolve the same.
I found out that, this is due to console.* statements I had in my JS. Apparently IE does not handle those statements gracefully and throws the error. Hence, AngularJS is not processed. However, console.* statements are executed fine when IE developer tools are active (i.e you have kept it open).
I blogged about the issues I faced (specific to IE) and how I resolved those. From the blog post, this specific issue is addressed under Issue 2 (AngularJS does not execute or executes only when IE developer tools are enabled)
Related
The Problem
I have a website running in IIS. If I rename or delete one of the layout page .cshtml files under /Views/ the site immediately begins throwing following yellow screen error as expected
The layout page "_Layout.cshtml" could not be found at the following path: "~/Views/_Layout.cshtml".
What surprises me is that if I recreate or rename the file so it is exactly like it was before, the yellow screen persists. Why is this particular 500 error sticky?
I currently think that this has something to do with IIS and is specifically related to error handling. The site immediately detects that the layout page file is missing. It does not immediately realize when the file is back in place.
Thanks!
Some interesting clues
This happens on all of my sites I've tried this on so far. It isn't related to a specific site
I tried this on two websites at the same time. On one site I repeatedly and consistently refreshed the page hoping for a success. On the other, I left it alone for several minutes before checking again. The site I leave alone will resolve its problems and find the layout page on disk again. The site I continually make requests to appears to display the error indefinitely.
What I've tried
I have reproduced the problem on Umbraco websites using Umbraco's default routing as well as regular MVC pages using custom routing. The problem is the same for both.
I don't have output caching configured in IIS
When I am reproducing the yellow screen error, I am able to reproduce the error in multiple browsers, so I don't believe it is related to browser caching
I checked on the httpRuntime in the root web.config and the fcnMode is set to fcnMode="Single"
I've fiddled around with the web.config customErrors and httpErrors. Nothing I've done here has affected the problem.
I am able to reproduce the problem on websites where there is no custom code for caching. No CDN. No load balancer.
Versions
IIS: I have reproduced the problem on Windows Server 2012R2 running IIS 8 and Windows 11 running IIS 10
CMS: All of the websites I have tested on so far are Umbraco 7 sites. However, I have reproduced the problem on pages that are routed using Umbraco's out of the box routing as well as pages that are just set up using MVC and aren't leveraging Umbraco.
It appears to be part of the behavior of FcnMode="Single". See https://learn.microsoft.com/en-us/dotnet/api/system.web.configuration.fcnmode?view=netframework-4.8. It isn't an issue with caching. It is a problem with the way that the site's file change notifications (FCN) are configured.
The sticky 500 behavior on renaming files happens when I use FcnMode="Single" but not when I use FcnMode="Default".
FcnMode="Single" will result in only a single object to monitor file changes. This single object is responsible for monitoring changes to files in the main directory and sub directories.
FcnMode="Default" will result in a separate object to monitor file changes for each directory.
Umbraco sites, by default, use FcnMode="Single". This makes sense because Umbraco sites cache under very deeply nested directories in /App_Data/. This can result in so many of these monitors that it can affect the performance of the site. There is a great explanation of FcnMode and why it matters for Umbraco here: https://shazwazza.com/post/all-about-aspnet-file-change-notification-fcn/
Unfortunately, it appears that the single file monitor can miss renames of files in some cases.
I'm running Firefox 36.0.4 on Windows 7 32-bit. I've diabled all add-ons, extensions and user scripts before retesting this.
I'd like to step through JavaScript code that is served up in a <script> tag in the HTML document being produced by a Java (Tomcat) web server.
Unfortunately, when I select the HTML document under Debugger > Sources, the source of the page returns to the login page of the application - it appears that session information is not being used to request the source.
I stepped through the server-side code and found that the correct session cookie values were being sent for the real page request and some AJAX requests sent by the page. However, when I tried to load the page source in the JavaScript debugger, I found that an incorrect session cookie was being sent by the JavaScript debugger.
I can replicate this behaviour in other webapps, not just my own. For example, Stack Overflow:
Is this a configuration issue, or a bug in the Firefox Developer Tools?
I can't reproduce your problem using StackOverflow as an example, at least in Firefox Developer Edition ( currently version 38 ):
One thing that might help - try disabling the cache while the toolbox is open - this setting is in the developer tools setting panel ( click on the 'gear' icon at the top right of the toolbox ):
After reviewing canuckistani's answer, I downloaded Firefox Developer Edition. Seemingly, the problem was fixed.
Five minutes in, I became sick of being asked whether to remember passwords and having to manually clear session cookies (I prefer being able to do it by simply closing the browser) - it makes testing easier.
As per usual, I went to Options > Privacy > History to disable this behaviour, by setting the value to Never remember history.
Changing this setting requires the browser to restart. However, upon restarting, I once again saw the same erroneous behaviour - the wrong session cookie was being sent to the web application again.
The workaround here is to not use the Never remember history setting. I have filed a bug report at Mozilla.org Bugzilla.
I have a web app with asp.net mvc 5 on running on iis 7.5. I have a photo upload page that I made with DropZone (a javascript ajax upload plugin). In my asp.net controller during certain errors, I return an httpstatuscode of 500 with a status description with a descriptive error. DropZone then displays this descriptive error. Everything works as it should on desktop devices, however when used on an iOS device it displays a generic "Internal Server Error" message.
I'm lost at how to troubleshoot this issue. I've placed javascript alerts throughout my javascript code to try and figure out what the issue is but that didn't reveal anything helpful. I've tried using the MIHTool ipad app and the HttpWatchBasic ipad app to try and set breakpoints but that was not helpful either.
Is there a way to remotely debug an asp.net web app from an iPad? (I have visual studio 2013 premium) Or does anyone have any ideas what may be causing a different status code to be sent?
UPDATE: It appears that iOS devices ignore any custom xhr.statusText and uses the standard default statusText (i.e. code 500 is Internal Server Error). As a work around (which I hate doing, but since this is primarily for use on company iPads I didn't have much choice) I've returned a different 500 class code for each possible exception and then in the javascript code check the status code and assign my own custom error message in the javascript code.
Quickest and easiest way to see the actual exception is to turn off custom errors in your Web.config - you'll then be able to view the actual stacktrace on the iPad.
If you'd like to be able to debug the exception, you should be able to trigger it by accessing the site from the iPad by hitting your windows development machine while running in the debugger. You'll need to configure IIS express to allow remote connections (editing application host.config), adding a urlacl, and opening the Windows firewall if necessary. There are numerous guides in setting this up online.
If you want to actually debug the JS in mobile Safari, this is possible from the Mac version of Safari - see http://webdesign.tutsplus.com/articles/quick-tip-using-web-inspector-to-debug-mobile-safari--webdesign-8787 for details.
Is there an "Angular/Dart" way to detect older unsupported browsers and prevent to continue with an elegant message (there are plenty of examples using javascript) rather than continue and show a weird layout with code that doesn't work?
Even the angulardart.org/demo site should do this IMO to stop IE8 (I know, but some enterprise customers still have those old browsers installed - and set as default - for legacy apps) from showing content that doesn't even work.
If Dart code cannot be executed the test has to be done in Js. I'm not aware of a library that makes this test.
The test should follow What browsers do you support as JavaScript compilation targets?.
I have a strange issue with an Asp.NET MVC application.
Using Asp.NET MVC 3 Preview 1 on IIS 7.5 - Integrated
After building the application everything runs fine. Then after some random amount of time (or sometimes after updating a view or js file) the application dies.
Meaning, requesting the root page, I get the 403 error and requesting any other page I get a 404 error.
After a rebuild everything works fine again for a little while until it dies again.
I am seeing this on two different development machines. Also, I have another application which is very similar (MVC 3, IIS etc) on both dev machines and this one runs without problem. I have inspected the config files in detail and cannot see anything of notable difference.
Does anyone know what could cause an application to die or where to look for further information? (I can still access elmah.axd though no information is there).
There's not much to go on here, but the 403 and 404 are clues that at least ASP.NET routing is not working; 403 is coming back because the web server thinks you want to do a directory browse, 404 because your request doesn't have a valid corresponding resource.
Since you are using the new version of MVC, I would suspect the issue may lye there. When you get the error condition, can you browse to a regular .aspx page? Does it execute server side code correctly?
You have the site hosted in IIS 7.5, not just the built in Visual Studio web server, right? Is it possible to turn on monitoring/event logging to see if IIS is taking a hit?
I apologize for not having any actual answer, sounds like you have a tough issue to debug.
Good Luck!