Jul 22

Written by: Michael Washington
7/22/2011 5:55 AM 

So you have deployed your LightSwitch application and everything is running fine. Then you get an email that a user is unable to perform a function. The problem you now have is that this is a problem that you can only see in production. When you need to preform debugging of a LightSwitch application in production, you want to use Tracing.

Getting the Most Out of the Save Pipeline in Visual Studio LightSwitch by Dan Seefeldt (http://www.code-magazine.com/articleprint.aspx?quickid=1103071), is the article you want to start with. It specifically talks about Tracing at the end of the article, however the entire article explains the “structure of how LightSwitch works” and that is important to understand what the data means that you discover when performing a Trace.

You can also read more about Tracing at this link: http://msdn.microsoft.com/en-us/library/wwh16c6c.aspx.

This article covers Tracing when your LightSwitch application is deployed as a “web application”.

Set-up Tracing Of Your Deployed Applications

Publish your LightSwitch application.

Open the web.config of your deployed application.

 

To enable Tracing, the Microsoft.LightSwitch.Trace.Enabled setting, and the trace enabled setting, must be set to true.

In this example, we will also set Microsoft.LightSwitch.Trace.LocalOnly to true (so Tracing will only work using ”http://localhost”), and Microsoft.LightSwitch.Trace.Level to verbose (so we will see more detailed information).

See the Dan Seefeldt article for an explanation of all the settings.

View Tracing In Your Web Browser

 

First open a web browser and navigate to your LightSwitch application.

 

 

Next, open another web browser, and go to the web address with ”/Trace.axd” at the end (for example: http://localhost/{Your LightSwitch Application}/Trace.axd).

 

 

If we look at the the screen that we have navigated to inside the LightSwitch screen designer, we can see that the collections on the left-hand side of the screen are called and show up in the Trace.

 

 

When we click View Details…

 

 

We will see some lines marked “A user implemented method does not exist”.

 

 

This refers to the the methods that are part of the “Save Pipeline” that you could have implemented code in but you did not.

 

Special Thanks

A special thanks to LightSwitch team member, Dan Seefeldt, for his assistance in creating this article.