Problems with BuildProvider code (chapter 1)

DevonTaig · September 4th, 2009, 10:08 PM

I'm getting an error, "Could not load type CarBuilderProvider.Car" when I attempt to compile the code in chapter 1. The .car file I have is below:

<?xml version="1.0" encoding="utf-8" ?>
<car name="SamsCar" >
<color>Blue</color>
<door>4</door>
<speed>123</speed>
</car>

And the XML snippet from the web.config file is below:

<buildProviders>
<add extension=".car" type="CarBuilderProvider.Car" />
</buildProviders>

I didn't modify the buildProvider code from the solutions at all.

Any ideas?

Imar · September 5th, 2009, 06:31 AM

Hi there,

Looks like you maybe missing a reference to the DLL containing your build provider? Maybe this helps:

http://social.msdn.microsoft.com/For...-7e1fa8f2ae28/

Cheers,

Imar

DevonTaig · September 5th, 2009, 09:00 PM

The trick here is to create a separate project and compile the BuildProvider as a .net .dll. Then in the ASP.NET website, that buildprovider .dll must be added as a reference...It seems that when you do that, it ends up going into the /bin folder (which I had added manually to the ASP.NET website).

There's not a description of those steps in the book...from the text it sounds like you would have the carbuildprovider.cs class in the app_code folder, but that will not work. The only thing related to the build provider in the app_code folder is the XML snippet that defines the car. You have to compile it and have it in the /bin folder. The screen shot (image 1-15 is helpful to look at, but in some ways it muddies the water by showing an app_data folder which I don't think is needed at all).

Thanks.

Imar · September 6th, 2009, 06:59 AM

Hi DevonTaig,

I don't have the book so I don't know what the original instructions were, but I just created a quick test site with just the App_Code folder and it worked fine. Here's what I did:

1. Create a class that inherits BuildProvider in its own namespace in App_Code

2. Created an override for GenerateCode in that class

3. Added the provider to the web.config like this:

Code:

 
<buildProviders>
<add extension=".sample" type="MyNamespace.MyClassname" />
</buildProviders>

4. Created a .sample file

5. Fired up a second instance of Visual Studio and debugged the first one with the web site and the build provider.

6. As soon as I start running the site with the build provider, my breakpoint in GenerateCode gets hit.

So, it seems to work fine when using App_Code.

Are you using a Web Site Project or a Web Application Project? App_Code is not used in WAPs....

Cheers,

Imar

jsymons · October 14th, 2009, 01:59 PM

DevonTaig & Imar,

I'm stumped on this one as well. I've added a reference to the compiled CarBuildProvider.dll which adds it to the Bin folder as was stated here and not in the book, yet I don't get Intellisense for the properties and method even though the class name itself can be accessed via Intellisense. All I see in Intellisense is Equals and ReferenceEquals.

Additionally, I also learned that if you have to recompile the CarBuildProvider.dll for whatever reason, your Website won't get a fresh copy of it. In order to get a new copy you have to right-click on the CarBuilderProvider.dll file within the Bin folder and select "Update Reference".

Any help would be greatly appreciated.

Thanks,

John

jsymons · October 14th, 2009, 02:11 PM

Sorry,

Posted to soon. I found the mistake. I previously had:

Code:

dim myCar as New Eclipse
' Got Equals and ReferenceEquals in Intellisense after typing the period here
Label1.Text = Eclipse.

When it should have been this (Note: The Intellisence worked as expected here):

Code:

dim myCar as New Eclipse
Label1.Text = myCar.Color

Thanks,

John