PersPective Wiki

One of my favourite wiki programs is PersPective, an open source, asp.net based wiki with a WYSIWYG editor.

The PersPective software itself is simple and elegant. PersPective stores all it’s data in xml files (another key selection criteria in the early days) utilizing a simple Xml schema. That means that the wiki is easy to backup, replicate and repair when the need arises. As a bonus, Alan Slater the author has always been helpful in extending Perspective In many cool ways. The releases of PersPective are of high quality and compatible, a tribute to Alan as a developer.

The extensibility of Perspective is also worth mentioning. It supports a facility called “Raw Includes” that allows new features to the wiki easily.  

If you’re after a good wiki, give it a try:

http://www.high-beyond.com 

Responding To Events From DataTemplate Controls in WPF

WPF provides the ability to create templated items for controls such as the list and grid.

These item templates allow any WPF controls including labels, text areas and buttons.  My problem was knowing how to create code that responds to the clicks of these buttons.  Wasn’t terribly obvious to me. 

Here’s an example:


  <DataTemplate x:Key="SomeListItemTemplate">
    <StackPanel>
     <TextBlock Text="{Binding Subject}" Width="188" Height="45.277"/>
      <Button x:Name="cmdDeleteItem" Width="59" Height="21.277" Content="Delete" >    
    </StackPanel>
  </DataTemplate>


The trick  appears to be to create “CommandBindings”.  These are an input mechanism in WPF that allows developers to define commands centrally and have them processed by the one piece of logic.

It appears this isn’t supported visually in Expression Blend unfortunately.

In order to solve my problem I had to do four things.

Firstly I defined a Window.CommandBindings section in my xaml file

<Window.CommandBindings>
<CommandBinding Command="local:MyCommands.DeleteItem" Executed="OnDeleteItem" />
</Window.CommandBindings>

(For this to work, add the ‘xmlns:local=”clr-namespace:MyProject” ‘ attribute against the Window Tag)

Secondly I created a class to host my custom command:


Public Class MyCommands
    Public Shared DeleteItem As New RoutedCommand("DeleteItem", GetType(MyTasksWPF.Main))
End Class

Thirdly I created the “OnDeleteItem” method to receive my event:

Public Sub OnDeleteItem(ByVal sender As Object, ByVal args As ExecutedRoutedEventArgs)
System.Windows.MessageBox.Show("So you wanted to delete " & CStr(args.Parameter) & " punk? Well didja?")
End Sub

Finally I updated the button definition to specify the command I defined:

<Button x:Name="cmdDeleteItem" Width="59" Height="21.277" Content="Delete"
Command="local:MyCommands.DeleteItem" CommandParameter="{Binding Id}"/>

Find the SDK docummentation on the subject here:

http://www.eggheadcafe.com/software/aspnet/29895215/commandbindings-in-blend.aspx

A full example demonstrating types of using CommandBinding:

http://adoguy.com/2007/03/28/WPF_Command_Example.aspx