MSBuild Inline Task

MSBuild Inline Task .xml

<!-- Sample Demonstrates Inline Tasks  © 2010 Sayed Ibrahim Hashimi -->
<?xml version="1.0" encoding="utf-8"?>
<Project ToolsVersion="4.0" 
         DefaultTargets="Demo" 
         xmlns="http://schemas.microsoft.com/developer/msbuild/2003">

  <UsingTask
    TaskName="FilterList"
    TaskFactory="CodeTaskFactory"
    AssemblyFile="$(MSBuildToolsPath)\Microsoft.Build.Tasks.v4.0.dll" >

    <ParameterGroup>
      <ListToFilter ParameterType="Microsoft.Build.Framework.ITaskItem[]" Required="true" />
      <Filter                                                             Required="true" />
      <FilteredList ParameterType="Microsoft.Build.Framework.ITaskItem[]" Output="true" />
    </ParameterGroup>

    <Task>
      <Using Namespace="System.Text.RegularExpressions" />

      <Code Type="Fragment" Language="cs">
        <![CDATA[
            var results = (from l in ListToFilter where Regex.IsMatch(l.ItemSpec, Filter) select l).ToList();
            FilteredList = results.ToArray();
        ]]>
      </Code>
    </Task>
  </UsingTask>

  <ItemGroup>
    <Source Include="src\01.cs" />
    <Source Include="src\02.cs" />
    <Source Include="test\test01.cs" />
    <Source Include="test\sub\test02.cs" />
    <Source Include="test\sub\test03.cs" />
    <Source Include="test\sub\sub2\test04.cs" />
  </ItemGroup>

  <Target Name="Demo">
    <FilterList ListToFilter="@(Source)" Filter="test">
      <Output ItemName="_filteredList" TaskParameter="FilteredList" />
    </FilterList>
    <Message Text="Filter: test. Results: @(_filteredList)" />

    <!-- Clear the list before calling again -->
    <ItemGroup>
      <_filteredList Remove="@(_filteredList)" />
    </ItemGroup>
    
    <Message Text="======" />

    <FilterList ListToFilter="@(Source)" Filter="sub\\">
      <Output ItemName="_filteredList" TaskParameter="FilteredList" />
    </FilterList>
    <Message Text="Filter: .\sub. Results: @(_filteredList)" />
  </Target>
</Project>