This section contains some exercises advanced over trivial examples.

Example 1: Cross Product

The following code realizes the cross product of two item groups. Please contribute more elegant ways and examples to do it.

Recipe

		 <Project xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
		     [<ItemGroup>]
		         <fruit Include="apple"/>
		         <fruit Include="rhubarb"/>
		         <fruit Include="apricot"/>
		         <form Include="cake"/>
		         <form Include="pie"/>
		         <form Include="sorbet"/>
		         <form Include="mousse"/>
		     [</ItemGroup>] 
	

		     <Target Name="Baking" Inputs="@(fruit)" Outputs="%(identity)">
		         <Message Text="@(fruit) %(form.identity)"/>
		     </Target>
		 </Project>
	

The fruits are enumerated by target batching, the forms by task batching. Appearantly, while baking, each individual fruit can be refered to using the at notation.

Enjoy your meal!

		 Baking Target:
		  apple cake
		  apple pie 
		  apple sorbet
		  apple mousse
		 Baking Target:
		  rhubarb cake
		  rhubarb pie
		  rhubarb sorbet
		  rhubarb mousse
		 Baking Target:
		  apricot cake
		  apricot pie
		  apricot sorbet
		  apricot mousse
	

Example 2: Intersection

This code was discussed as Brainteaser at http://blogs.msdn.com/msbuild/archive/2006/05/18/601146.aspx.

		 <Project xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
		     [<ItemGroup>]
		         <GroupA Include="file1.txt"/>
		         <GroupA Include="file2.txt"/>
		         <GroupA Include="file3.txt"/>
		         <GroupA Include="file4.txt"/>
		     [</ItemGroup>]
	

		     [<ItemGroup>]
		         <GroupB Include="file1.txt"/>
		         <GroupB Include="file3.txt"/>
		         <GroupB Include="file5.txt"/>
		     [</ItemGroup>]
	

		     <Target Name="Build">
		         [<CreateItem] Include="@(GroupA)" Condition="'%(Identity)' != _ and '@(GroupA)' != _ and '@(GroupB)' != ''">
		             <Output TaskParameter="Include" ItemName="GroupC"/>
		        [</CreateItem>]
		        <Message Text="@(GroupC)"/>
		     </Target>
		 </Project>
	

Example 3: Filtering

A demonstration how item groups can be filtered by their metadata.

Advice

		 <Project xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
		     [<ItemGroup>]
		         <fruit Include="apple">
		             <consistency>firm</consistency>
		         </fruit>
		         <fruit Include="orange">
		             <consistency>pulpy</consistency>
		         </fruit>
		         <fruit Include="banana">
		             <consistency>softish</consistency>
		         </fruit>
		         <fruit Include="pear">
		             <consistency>unsound</consistency>
		         </fruit>
		         <fruit Include="apricot">
		             <consistency>unsound</consistency>
		         </fruit>
		     [</ItemGroup>]
	

		     <Target Name="Compost">
		         <Message Text="%(fruit.identity)" Condition="%(consistency) == 'pulpy' or %(consistency) == 'unsound' "/>
		     </Target>
		 </Project>
	

Execution

		 Compost Target:
		     orange
		     pear
		     apricot
	

Variation

Choose as message text :

		 @(fruit)
	

What is the output?