RT-blog

Accessing controls using FindControl() in an UpdateProgress control

rtblog@realtechnology.com — Tue, 12 Jan 2010 17:27:21 GMT

While trying to do some code-behind manipulation of a page I had trouble accessing the controls contained by an UpdateProgress control. On the same page I have an UpdatePanel and I'm able to use FindControl() to locate controls contained by it in the CreateChildControls event (or any other event for that matter). Not so with the UpdateProgress control! No matter what I tried the UpdateProgress control would not find any controls.

I finally stumbled upon a tip that you needed to do this in the page's PreRenderComplete event. Like this:

void Page_PreRenderComplete( object sender, EventArgs e )
{
                Image ImageProgress = (Image)UpdateProgress1.FindControl( "ImageProgress" );
                if( ImageProgress != null )
                {
                    //Do something with the image
                }
}

ASP.net 2.0, AJAX, UpdateProgress

ERROR [IM003] Specified driver could not be loaded due to system error 5

rtblog@realtechnology.com — Fri, 08 Jan 2010 01:51:36 GMT

I recently got an unusual ODBC error after I set up a system DSN for an ASP.Net application.

ERROR [IM003] Specified driver could not be loaded due to system error 5

Simple fix: make sure that the account which ASP.Net is running under has permissions to read from the directory where the ODBC driver is located. Doh!

LLBLGEN PRO Extended/Custom properties on table fields

rtblog@realtechnology.com — Wed, 02 Dec 2009 20:10:14 GMT

Using extended/custom properties in LLBLGEN Pro is a bit confusing. Here are some tips which I hope will save you time.

To view custom properties on an entity, right-click the entity name in the project explorer and choose "Edit/Properties". Choose the Code Gen. Options tab and then the Custom Properties tab.

To view custom properties on a entity field, right-click the entity name in the project explorer and choose "Edit/Properties". Choose the Entity Fields tab, select the field from the list of Mapped Entity Fields, then choose the Custom Properties tab.

By default LLBLGen does not import your custom properties which you define on fields or tables. To enable this, go to the preferences screen and change the value of RetrieveDBCustomProperties to true. When this value is false, LLBLGEN will not retrieve custom properties, even if you check the "Custom Properties" checkbox when creating a new project or refreshing a schema.

When creating a new project, if you check the box to retrieve "Custom properties", then LLBLGen will retrieve the properties for tables and their fields. If you do not do this when creating a project then you will have to take an extra step to later retrieve the custom properties of your fields (explained below).

When you refresh a catalog, custom properties for entities and fields will not be updated, even if you check the "Custom Properties" checkbox. To update custom properties you must change the value of UpdateCustomPropertiesAfterRefresh to true (in Preferences). The catch here is it will only update existing properties. If you did not include custom properties when you created a project or you add a new property after the project was created, it will not get updated. However, you can manually add the custom property to the entity or entity field, in which case it will then be updated on future refreshes of the catalog.

These settings are all defaulted this way so that projects don't grow excessively large as a result of custom property data inserted by third-party modelling tools.

One way to use custom properties and avoid this problem is to change the preferences as indicated above. When you create a project, do not include custom properties in the elements to be retrieved from the schema. Edit your entities and either manually put in the custom properties you'd like to include or use the "Add Custom properties" plugin. This is useful if all your custom properties are named the same in each field. For instance if each field has a "Description" property, use the plug-in to add a "Description" property to each field. When you next update the project schema and include custom properties, the values for "Description" will be pulled from the database, but other custom properties will be ignored. The plug-in can be access by right-clicking on the entity name in the project explorer and choosing "Run Plug-in".

Alternatively, you could include all the properties when you first create the project and delete the ones you do not want to keep in the project. The remaining custom properties will be refreshed when you want them to and the deleted properties will be ignored.

LLBLGen Pro v2.6, Custom properties, extended properties

SSIS Excel Connection Manager error

rtblog@realtechnology.com — Fri, 20 Feb 2009 23:51:54 GMT

One day it works, the next it doesn't. A solution to the error "The AcquireConnection method call to the connection manager "Excel Connection Manager" failed with error code..."

Visual Studio 2008: Unable to start debugging on web server. An authentication error occurred...

rtblog@realtechnology.com — Fri, 09 Jan 2009 00:10:10 GMT

My dev server is a Win 2003 machine with IIS 6.0. I've got a number of web sites set up which I reference via URLs such as http://site1.localhost, http://site2.localhost, etc. By putting entries in my HOSTS file which point back to 127.0.0.1, I can use those URLs to access the sites because I set up Host Headers for each site to look for its specific URL.

After installing VS 2008, I suddenly lost the ability to debug web applications on my local machine. I had been using VS 2005 successfully before that.

"Unable to start debugging on the web server. An authentication error occurred while communicating with the web server."

I did a lot of fruitless searching on the web. None of the solutions worked: Integrated Windows Authentication must be enabled for the website - yes it was. ASP.Net security settings all checked out. ACL's were all okay. I found that if I disabled Anonymous logins for the website in IIS, I could see that Integrated Windows Authentication wasn't working properly. When viewing the site in my browser I would be asked to log in, but my windows credentials would not work*. Arg!

After examining IIS log files, it was clear that Visual Studio was trying to log in to the web server using the same account I was logged into Windows with. So we were both having the same problem. For some reason IIS wasn't handling IWA properly.

I turned on auditing for logon failures and examined the security event log.

Hmm, this is interesting:

Event Type: Failure Audit
Event Source: Security
Event Category: Logon/Logoff
Event ID: 537
Date:  1/8/2009
Time:  12:56:45 PM
User:  NT AUTHORITY\SYSTEM
Computer: ISIS
Description:
Logon Failure:
  Reason:  An error occurred during logon
  User Name: administrator
  Domain:  isis
  Logon Type: 3
  Logon Process: ÈùÈ
  Authentication Package: NTLM
  Workstation Name: ISIS
  Status code: 0xC000006D
  Substatus code: 0x0
  Caller User Name: -
  Caller Domain: -
  Caller Logon ID: -
  Caller Process ID: -
  Transited Services: -
  Source Network Address: 127.0.0.1
  Source Port: 4869

Well, no, it isn't that interesting, but the error code led me to this explanation:

You receive error 401.1 when you browse a Web site that uses Integrated Authentication and is hosted on IIS 5.1 or IIS 6

As it turns out, Windows Server 2003 Service Pack 1 (SP1) has a loopback check security feature. Since I was browsing locally and using host headers to access my websites, Windows was refusing to validate the request (or something like that).

After following the instructions for the workaround, VS debugging works fine now. I felt I needed to connect the dots here because my initial searches didn't turn up this solution.

*This had been a problem prior to intalling VS 2008, but I was able to work around it by enabling anonymous access to the websites.

The attribute key cannot be found - SSAS 2005 dimensions

rtblog@realtechnology.com — Wed, 16 Jul 2008 14:50:57 GMT

Another gotcha in Sql Server Analysis Services (SSAS) 2005 related to nullable foreign keys...

Let's say you have DimensionA which contains a foreign key to the related dimension DimensionB and that relationship is optional (nullable foreign key). DimensionB is represented as AttributeB within DimensionA.

When I first created DimensionA and related it to my fact table, everything worked nicely. I then decided to have the name column for AttributeB show the text value for DImensionB's key rather than they key itself. I figured this would make things go more quickly when building reports. I used object binding on the NameColumn and set the source table and source column. Suddenly I started getting the error "The attribute key cannot be found" when I tried to process the cube. Huh?

I checked my source tables and of course the key did exist. I finally realized that I could examine the key values being stored for DimensionA and indeed the key was missing, even though it was present in the source data.

Looking at the source data I also noticed that this particular key had a null value for AttributeB. It became clear that rather than looking up the values for the name column, SSAS was creating an inner join between the tables used for DimensionA and DimensionB and in the process dropping all the rows with a null value in that related field. Arg!

Getting rid of the object binding for AttributeB's name column fixed the problem.

SSAS nullable foreign keys dimensions

Optional relationships in SSAS 2005

rtblog@realtechnology.com — Tue, 15 Jul 2008 21:16:34 GMT

On a recent project using Sql Server Analysis Server (SSAS) 2005, I ran into some challenges with fact tables that had optional relationships (nullable foreign keys) to related dimension tables.

I used a design were FactTableA had a regular relationship to DimensionA and DimensionB, however, these were both optional relationships. The cube functioned correctly until I added a referenced relationship to DimensionC via DimensionA. When I did this, the count of records in FactTableA suddenly dropped to a value corresponding to the count of non-null values for the foreign key referencing DimensionA. The cube was forming an inner join between FactTableA and DimensionC via DimensionA; not what I wanted at all.

The fix was simple, in the "Define Relationship" screen for DimensionC, I unchecked the "Materialize" checkbox. The documentation doesn't mention this impact on the data, it merely mentions that perfomance is improved when the value is checked.

SSAS 2005 nullable foreign keys referenced dimensions

RadioButtonList - hanging indent (ASP.Net)

rtblog@realtechnology.com — Mon, 09 Jun 2008 20:49:38 GMT

Here's how to make hanging indents for radiobuttonlists in ASP.Net!

You must choose RepeatLayout="Table" and then create styles to apply to that table.

[Test in IE7 and Firefox 2]

ID="RadioButtonListSessionChoice"
runat="server"
CssClass="rbChoice"
RepeatLayout="Table"
RepeatColumns="1"
/>

iMac: Buyer beware

rtblog@realtechnology.com — Fri, 16 May 2008 14:48:58 GMT

I love my iMac, I hate my iMac.

I've owned my iMac for about 2 years. I use it for music and photos, mostly, and when it's not in use it makes a great picture frame for displaying my photos.

BUT

My LCD screen suddenly started devloping vertical lines just like these.

So, while I love my iMac - don't buy one unless you get the extended AppleCare warranty!

Here's an online petition to get Apple to correct this problem. (yeah right)

iConcertCal - Cool iTunes plug-in

rtblog@realtechnology.com — Fri, 05 Oct 2007 19:10:11 GMT

iTunes plug-in for finding live music.