Mini Post – DotNetNuke and web.config problems

I could have Twittered this but I wanted to put it here: Every now and again I find myself refreshing my developer’s copy of my project on my local computer from source control.

The way I have source control is primitive and probably incorrect. I tend to save ALL of my project (DotNetNuke included) into source control, so when I get a clean setup, I can basically run it out of the box.

This particular time, I was working with a different database than I normally do. Because of this, my source control wrote over my web.config and copied the wrong database settings, which resulted in the web.config pointing to a no-longer existing database.

When I loaded up my website, I was greeted with the installation wizard from DotNetNuke. “Okay,” I thought, “Perhaps I forgot to update this particular database with the new DNN version.” I clicked on next a few times and realized it was just the wrong database being referenced. I changed the web.config to be the correct database and credentials and all was well…

Or was it?

I loaded up my project and I was getting rather unhelpful “I need to put a ScriptManager on the page in order to use AJAX.net” error. I just couldn’t figure it out! It worked before! Long story short, the DNN install wizard messed around with the web.config and broke a few things configured specifically to my install. Once I pulled up an older web.config, everything worked perfectly.

This wasted about 2 hours of my time (which I don’t really have) and was easily avoidable if I was paying attention.

Lesson learned: Always be methodical with processes which you perform regularly.  If something strange goes wrong within the process, it probably doesn’t belong and should be approached very, VERY carefully.

DotNetNuke Settings Issue: Truncated Data

DotNetNuke is great.  It has a great established core, along with a fairly straight forward process for developing extended modules.  You can use the already established DotNetNuke settings framework in order to facilitate settings for each instance of your own module.

We have a unique install in which we have central data that is shared by many custom modules.  I needed a way to have specific settings per portal, so I built a custom settings library.  I also wanted to be able to override these settings so I built in an XML parser to do so.

I found out the hard way that the settings table has an nvarchar size of 2000.  This almost never affected us, since the XML is generally smaller than 2000 characters, but I had one setting that went over.  It messed up my xml, and broke my module.

My immediate fix was to change the core database.  I made the settings to be nvarchar(MAX), and set up the add and update stored procedures to accomodate them.

I believe the best way to fix the issue without changing the core is to create another table, which either has a text type or a varchar(MAX) as the value.

Visible=”false” vs. display:none;

I find that when you are a new programmer or a programmer using a technology for the first time, there are a few gotchas’ that could make or break your learning experience.  When learning the power of .NET, especially after developing primarily in PHP,  the differences between Visible=”false” and display:none; was a huge gotcha for me.   I figured I’d help you realize what exactly the differences are and when you should use one or the other.  Take the source code:

<asp:Panel style="display:none;">
Error Message
</asp:Panel>

and

<asp:Panel Visible="false">
Error Message
</asp:Panel>

If you were to render both of these, you would see the screen the same thing: nothing.  However, if you look at the source of both of them, you will realize that the former will appear in the source but the latter will not.  That’s because in the first example, command display:none is CSS, which is client-side and in the second example, “Visible” is a server-side. On more complex pages, they are very much different.

When to use the display:none;

Let’s say you have a form in which you want to hide some elements of it, entirely for user experience (perhaps you want to hide the address field in case it is optional). If you used Visible = false, the button would have to postback, run back-end code to change the visible=”true” and render back to the browser the entire page. This exercise taxes the server, and is not an optimal user experience. It would be nicer to open the box via javascript.  if you used style:none; on an element, you would just need to run display:block; in order to show it.

When to use Visible=”false”

If you will never need access to the element via Javascript, then this is the better function to use.  This way, the element will never get rendered, and therefore keep the precious bandwidth of your pages to a minimum.  Also, maybe you want to run server-side code when you restore the address field. In this case, it is better to use Visible=”false”

I hope this helps you better understand the differences between the two types of hiding elements in .NET.  If you have any questions, let me know!

ModalPopupExtender .Show() Caveat

I’ll admit it… I don’t mind AJAX.NET.  In fact, I like a lot of the toolkit controls they provide.  Because I am “chained” to .NET and DotNetNuke, I don’t much of a choice when it comes to bleeding-edge technology.

One thing I tend to use frequently is the ModalPopupExtender.  I had a requirement to show the modal popup when the page loads.  Easy enough, I just instansiate the code and in the onLoad code-behind do mpe.Show().

However, this didn’t work It gave me an ugly error.  After sifting through a bunch of unhelpful forum posts online, I came across this issue in the AJAX Control Toolkit issue tracker.  Reading through the description, you notice that the problem has to do with the fact that there is a missing semi-colon if you try to invoke the modal through server-side on a page with validation.

Because the modal I was programming would not need the validation on the page, I simply turned off validation when the modal was invoked.  This worked like a charm.  If you require validation with the modal, I strongly suggest you check out the issue tracker page.