Report Parameter Default Values

While developing SSRS reports I almost always define default report parameters in case I need to fix some issue with layout or data itself. It saves some time as I don't have to fill report parameters each time I want to preview report with new changes applied.
But after report is deployed to production report server and users start using it default parameters are not that handy there. Especially with heavy statistics reports (that takes more than several seconds to process request) when report engine starts processing request at once using default parameters. Almost in all cases default parameters does not match user's. Nobody wants to wait extra before submitting desired input parameters especially when "extra" is several minutes long.


So don't forget to empty default parameters prior to deploying report or if deployed empty them and redeploy.

PS: And don't forget to update report subscriptions as well in case you have some.


Regards,
Oleh

Alternating background colors for odd and even tablix rows

In this blog post I will describe how you can add alternating background colors to SSRS tablix odd and even rows.

What do you need to know is that expression evaluation rules in RS 2008 have changed as a result of the new on-demand processing model. As a result, state in class-level instance variables is discarded as you page through the report which makes maintaining state trickier between page requests. However, RS 2008 introduces report variables that guarantee one-time evaluation semantics.

How we can reuse it to accomplish our goal:

• Create a function that will update _evenRow flag state each time it's called.

Open report properties box -> Code tab -> Add next code:

Public _evenRow As Boolean

Public Function EvenRow() As Boolean

 _evenRow = Not _evenRow

return _evenRow

End Function

• Create a variable within Row group and set the expression to call EvenRow function. Since it will be evaluated one time per each row it's what we need.

• Set row background color depending on variable state.

=iif(Variables!EvenRow.Value, "LightGrey", "Transparent")

• and finally the outcome

Regards,
Oleh

What's new in WCF 4.0, WF 4.0

A Developer’s Introduction to Windows Communication Foundation (WCF) .NET 4 Beta 1 describing upcoming WCF 4.0 changes has been published on MSDN. The basic idea is to simplify developer experience and provide more integration with WF 4.0. Introduction to WF 4.0 changes could be found here.


Enjoy!
Regards,
Oleh

Sysinternals Suite updated

Sysinternals Suite has been refreshed with latest releases and new utilities.

"The Sysinternals Troubleshooting Utilities have been rolled up into a single Suite of tools. This file contains the individual troubleshooting tools and help files. It does not contain non-troubleshooting tools like the BSOD Screen Saver or NotMyFault."

Latest version could be downloaded here.

Enjoy!

Oleh

SQL Server 2008 R2 August CTP

Microsoft released SQL Server 2008 R2 August CTP:

• Start exploring it.
• Follow what's new in August CTP.
• SQL Server 2008 R2: Virtualization for Databases.
• SQL Server 2008 R2: The DAC Pack.
• 
  

  New / changed columns in SQL Server 2008 R2 DMVs.

• Upcoming Reporting Services changes.

Regards,

Oleh

Wcf svc mime type on IIS.

I have started exploring WCF. The first issue I have got into was that there is no .svc MIME map on  IIS7 on Vista. When I tried to locate the service I always had the same exception: "HTTP Error 404.3 - Not Found. The page you are requesting cannot be served because of the extension configuration. If the page is a script, add a handler. If the file should be downloaded, add a MIME map."

In order to resolve this you need to run "\%windir%\Microsoft.NET\Framework\v3.0\Windows Communication Foundation\ServiceModelReg.exe -i". It will create required .svc mapping.

Regards,
Oleh

Variable Scope in JavaScript

Recently I had to add some business logic to the javascript client call back function. I had to iterate through a collection of custom business objects and update state of each of them. I made a mistake in the for loop: declared loop counter not as a local variable!
Instead of

for (var i = 0; i < myCollection.length; i++)

I had

for (i = 0; i < myCollection.length; i++)

The outcome was that I was receiving an error "__pendingCallbacks[...].async is null or not an object" every time my function was executed.


My problem was with the i variable scope. It was declared higher in the stack in the WebForm_CallbackComplete() function

for (var i = 0; i < __pendingCallbacks.length; i++)

so really I was using and updating that variable.



Weird behavior after C# where callee is not able to access its caller's local variables.

But I found my mistake pretty fast.

Hope it helps someone.
Regards,
Oleh