ShowUsYour<Blog> : Whidbey

RegexLib V2 - now with added ASP.NET V2 :)

digory — Thu, 09 Jun 2005 20:56:00 GMT

The other day I posted a blog entry about the migration of RegexLib to ASP.NET V2 - the article can be found here:

http://markitup.com/Blog/archive/2005/06/07/50.aspx

In the coming week I'm planning to post a source code viewer so that you can see how that site has been put together and I'm also planning to release a couple of articles (not sure where yet) - the first of which will be an article describing how I migrated the existing users into the new Membership feature.

ASP 2 Quickstarts

digory — Mon, 04 Apr 2005 23:48:00 GMT

Very Nice!

http://beta.asp.net/quickstart/aspnet/Default.aspx

What CommandName's to use in a FormView

digory — Fri, 01 Apr 2005 20:31:00 GMT

taken from Fredrik's blog:

Paging:

Next

Prev

First

Last

The FormView has support for paging so we don’t really need to add button controls for those commands. We only need to use those if we want to create our own custom paging.

For changing modes:

New

Cancel

Edit

The New command will change the mode of the FormView to the Insert mode. The Cancel will turn back the mode to its default mode. The Edit will turn the mode into Edit mode.

For actions:

Insert

Delete

Update

When we press a button with the Insert command specified the FormView will execute the associated DataSource control’s InsertCommand. If the CommandName of the button is set to Delete or Update the DataSource’s DeleteCommand or UpdateCommand will be executed. By default the SelectCommand of the DataSource control will be executed.

Using generics to build generic data logic layers

digory — Tue, 29 Mar 2005 08:12:00 GMT

Consider exposing raw Generic collections from your data logic layers, such as:

   public class PersonManager {
        ...
        public List<Person> ListPeople(...) { ... } ;
   }

When I started messing around with building applications in 2.0 I quickly wrapped Generic collections like so:

  public class PersonCollection : List<Person> {
     ... 
  }

This was normally done so that I could hang a Sort method off of them:

  public class PersonCollection : List<Person>, IBidirectionalSort {
     ... 
     public void Sort( string sortExpression, bool isAscending ) { ... }
  }

The downside of this approach is that you end up writing fiddly code around calls to generic helper methods.

As an example, let's say that I write a nice generic helper method to page my collections:

    public static void Page(ref List<T> data, int maximumRows, int startRowIndex) 
        where T : IDataObject, new() {

        if (data.Count > 0) {
            if (maximumRows > 0 && startRowIndex >= 0) {
                List<T> tmpColl = null;

                int remainingRowCount = data.Count - startRowIndex;
                int count = (remainingRowCount >= maximumRows) ? maximumRows : remainingRowCount;

                if (count > 0) {
                    tmpColl = new List<T>();
                    tmpColl.AddRange(data.GetRange(startRowIndex, count));
                }
                data = tmpColl;
            }
        }
    }

If I’ve wrapped my collection – as per the PersonCollection example – then using the generic Page method will require temporary object creation when I’m calling it, something like:

   public PersonCollection ListPeople(...) { 
       ...
       PersonCollection people = FillList( reader ) ;
       List<Person> tmp = Page( people, 20, 0 ) ;
       PersonCollection peopleToReturn = new PersonCollection() ;
       peopleToReturn.AddRange( tmp ) ;
       return peopleToReturn ;
   }

So, you can see that by the time we have many generic methods, working with temporary objects becomes cumbersome. Exposing List<Person> from this method would lead you to build your surrounding methods – such as FillList and Page – to work with your code better but will also lead to leaner code:

    public List<Person> ListPeople(...) { 
       ...
       List<Person> people = FillList<Person>( reader ) ;
       return Page<Person>( people, 20, 0 ) ;
    }

Using the SiteMapDataSource to display lists of links

digory — Tue, 29 Mar 2005 00:09:00 GMT

Danny Chen just blogged about the SiteMap and showed some interesting ways to make use of custom attributes:

http://weblogs.asp.net/dannychen/archive/2005/03/28/396099.aspx

There's another one that I'd like to add to this list. Commonly people are using UL elements to create navigational links because they require less Html to be emitted in the page and are easily styled into nice looking links. This is the approach that modern applications such as CommunityServer and ProjectDistributor use for their lists of links. So how would you do that with a SiteMap? The answer is actually pretty simple because you can bind a SiteMapDataSource directly to a Repeater.

<asp:SiteMapDataSource id="myDataSource" runat="server" ShowStartingNode="false" />

That will give you a nice list of clickable links.

On my site I actually only required a subset of the items in the SiteMap to be rendered on a specific menu. For example, I had a left navigation menu which only displays a subset of the total items. In this case I can use the technique that Danny showed off by adding a custom attribute to my SiteMapNode's like so:

<?xml version="1.0" encoding="utf-8" ?>
<siteMap xmlns="http://schemas.microsoft.com/AspNet/SiteMap-File-1.0" >
    <siteMapNode url="Home.aspx" title="Home" DisplayOnLeft="true">
      <siteMapNode url="Work.aspx" title="Work" />
      <siteMapNode url="School.aspx" title="School" DisplayOnLeft="true" />
    </siteMapNode>
</siteMap>

So, you can see that 2 of the nodes contain a DisplayOnLeft attribute which is set to true. Now, to conditionally display those items in my sidebar navigation list I can hook the Repeater's ItemDataBound event and write logic like so...

SiteMapNode node = e.Item.DataItem as SiteMapNode ;
string display = node["DisplayOnLeft"];
if( string.IsEmptyOrNull( display ) || display != "true" ) {
e.Item.Visible = false ;
}

Getting ASP.NET Membership running against your own database

digory — Sat, 26 Mar 2005 09:33:00 GMT

If you want to install the ASP.NET V2 tables and procedures for things such as Membership, Personalization, etc you need to run the aspnet_regsql.exe tool against your database. The tool can be found in the %windir%\Microsoft.NET\Framework\{FRAMEWORKVERSION} folder.

Once you've run that tool, then it's just a matter of replacing the ConnectionString entry in your web.config file to point to your database:

  <configuration xmlns="http://schemas.microsoft.com/.NetConfiguration/v2.0">

    <connectionStrings>
      <remove name="LocalSqlServer" />
      <add connectionString="CONN STRING" name="LocalSqlServer" providerName="System.Sql.DbClient" />
    </connectionStrings>

  </configuration>

After that, the built-in API's will read and write from your database for that application.

Health monitoring in ASP.NET V2

digory — Wed, 23 Feb 2005 21:41:00 GMT

Here's a couple of nice articles about the new HealthMonitoring feature in Whidbey:

http://weblogs.asp.net/dr.netjes/archive/2004/12/09/279101.aspx
http://msmvps.com/gbvb/archive/2004/09/15/13578.aspx

Definitely worth a read as this makes it super-easy to put custom logging code into your applications.

The sexy new web

digory — Tue, 22 Feb 2005 02:39:00 GMT

A nice article about how we are starting to expand and build smarter, richer applications on the web.

http://adaptivepath.com/publications/essays/archives/000385.php

I know that I've said this before but, articles such as this really emphasize how the ASP.NET team have got it right with what they are delivering in Whidbey. Things such as the client-side scripting callbacks will bring the ability to produce a "GMail"-type experience within the reach of many more developers and, as a result, we will start to enjoy a new breed of applications.

We've been focussing a lot of energy looking into how to incorporate smart design such as this into our new blogging application for performing tasks such as spell-checking to reduce the instances of unneccessary round-tripping.

Post-Cache substitution sample

digory — Tue, 15 Feb 2005 11:30:00 GMT

Having read Nikhil's great post about this topic recently, I thought that I'd add a working demo of that sample to the Whidbey group on ProjectDistributor. You can grab the source here.

http://projectdistributor.net/Projects/Project.aspx?projectId=75

Fredrik has just released a new cut of PermissionManager

digory — Mon, 07 Feb 2005 22:28:00 GMT

You can read his announcement here:

http://fredrik.nsquared2.com/viewpost.aspx?PostID=279

Fredrik is doing some awesome stuff with ASP.NET V2 and this project is a great example of that. If you want to learn about how - and possibly why - you would want to implement your own provider for a set of data access functionality such as this, then I highly recommend this code as a good example.

The code demonstrates how to create and initialize the provider, how to work with the configuration settings and how to interract with the proivider via a business manager object.