When you import another msbuild file, what is the order of evaluation?

Question

I have a shared properties file shared.properties.proj

<Project  xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
  <PropertyGroup>
    <SharedAssemblySearch>$(MSBuildProjectDirectory)\..\Shared Assemblies</SharedAssemblySearch>
    <ParentDir>..</ParentDir>
    <SharedAssemblySearch Condition="!Exists('$(SharedAssemblySearch)')">$(ParentDir)\$(SharedAssemblySearch)</SharedAssemblySearch>
    <SharedAssemblySearch Condition="!Exists('$(SharedAssemblySearch)')">$(ParentDir)\$(SharedAssemblySearch)</SharedAssemblySearch>
    <SharedAssemblySearch Condition="!Exists('$(SharedAssemblySearch)')">$(ParentDir)\$(SharedAssemblySearch)</SharedAssemblySearch>
    <SharedAssemblySearch Condition="!Exists('$(SharedAssemblySearch)')">$(ParentDir)\$(SharedAssemblySearch)</SharedAssemblySearch>
    <SharedAssemblySearch Condition="!Exists('$(SharedAssemblySearch)')">$(ParentDir)\$(SharedAssemblySearch)</SharedAssemblySearch>
    <SharedAssemblySearch Condition="!Exists('$(SharedAssemblySearch)')">$(ParentDir)\$(SharedAssemblySearch)</SharedAssemblySearch>
    <SharedAssemblyPath Condition="Exists('$(SharedAssemblySearch)')">$(SharedAssemblySearch)</SharedAssemblyPath>
    <SharedAssemblySearch Condition="!Exists('$(SharedAssemblySearch)')">..\SharedAssemblies</SharedAssemblySearch>
    <SharedAssemblySearch Condition="!Exists('$(SharedAssemblySearch)')">$(ParentDir)\$(SharedAssemblySearch)</SharedAssemblySearch>
    <SharedAssemblySearch Condition="!Exists('$(SharedAssemblySearch)')">$(ParentDir)\$(SharedAssemblySearch)</SharedAssemblySearch>
    <SharedAssemblySearch Condition="!Exists('$(SharedAssemblySearch)')">$(ParentDir)\$(SharedAssemblySearch)</SharedAssemblySearch>
    <SharedAssemblySearch Condition="!Exists('$(SharedAssemblySearch)')">$(ParentDir)\$(SharedAssemblySearch)</SharedAssemblySearch>
    <SharedAssemblyPath Condition="Exists('$(SharedAssemblySearch)')">$(SharedAssemblySearch)</SharedAssemblyPath>
 </PropertyGroup>
</project>

I am searching for whatever level parent directory contains the directory named Shared Assemblies. or alternatively SharedAssemblies

I'd like to put this code in a central location for the sln, so that all the projects can just import it. projects in the sln are not all at the same hierarchy level.

Sample .csproj

    <?xml version="1.0" encoding="utf-8"?>
    <Project ToolsVersion="4.0" DefaultTargets="Build" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
    <Import Project="$([MSBuild]::GetDirectoryNameOfFileAbove($(MSBuildThisFileDirectory), Shared.Properties.proj))\Shared.Properties.proj"
   Condition=" '$([MSBuild]::GetDirectoryNameOfFileAbove($(MSBuildThisFileDirectory), Shared.Properties.proj))' != '' "/>
    <ItemGroup>
    <Reference Include="EntityFramework">
      <HintPath>$(SharedAssemblyPath)\NuGet\EntityFramework.4.3.0\lib\net40\EntityFramework.dll</HintPath>
     </Reference>
    </ItemGroup>
  <Target Name="CheckReferencePaths" BeforeTargets="ResolveAssemblyReferences">
    <Message Importance="high" Text="Doing CheckReferencePaths" />
    <ItemGroup>
     <SharedAssemblyPathItem Include="$(SharedAssemblyPath)" />
    </ItemGroup>
    <Warning Condition="!Exists('@(SharedAssemblyPathItem)')" Text="SharedAssemblyPath not found at '@(SharedAssemblyPathItem)'" />
    <Warning Condition="!Exists('@(SharedAssemblyPathItem)')" Text="SharedAssemblyPath not found at '@(SharedAssemblyPathItem->'%(FullPath)')'" />
    <Message Condition="!Exists('%(Reference.HintPath)')" Text="FullPath=%(Reference.HintPath)" Importance="high" />

I have this working in the main project without pushing the property group out to a satellite file that I import, but now want to make it reusable between other projects that could have shared references.

The BeforeTargets target shows this on the new attempt that is not working:

CheckReferencePaths: Doing CheckReferencePaths D:\projects\Team\Project\Adapters\DbAdapter\dbadapter.csproj(103,5): warning : SharedAssemblyPath not found at '' D:\projects\Team\Project\Adapters\DbAdapter\dbadapter.csproj(104,5): warning : SharedAssemblyPath not found at ''
FullPath=\NuGet\EntityFramework.4.3.0\lib\net40\EntityFramework.dll
FullPath=

How can I get the project file that imports the shared to evaluate the imported project's properties before it evaluates the item groups' hintpaths. Or is the evaluation order proper, but something else in my construction is incorrect?

Answer 1

Your question lead me to find this valuable info on MSDN. I'm posting it here for keeping the answer self-contained.

---

Order of Evaluation

When MSBuild reaches an Import element, the imported project is effectively inserted into the importing project at the location of the Import element. Therefore, the location of the Import element can affect the values of properties and items. It is important to understand the properties and items that are set by the imported project, and the properties and items that the imported project uses.

When the project builds, all properties are evaluated first, followed by items. For example, the following XML defines the imported project file MyCommon.targets:

<Project xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
    <PropertyGroup>
        <Name>MyCommon</Name>
    </PropertyGroup>

    <Target Name="Go">
        <Message Text="Name='$(Name)'"/>
    </Target>
</Project>

The following XML defines MyApp.proj, which imports MyCommon.targets:

<Project
    DefaultTargets="Go"
    xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
    <PropertyGroup>
        <Name>MyApp</Name>
    </PropertyGroup>
    <Import Project="MyCommon.targets"/>
</Project>

When the project builds, the following message is displayed:

Name="MyCommon"

Because the project is imported after the property Name has been defined in MyApp.proj, the definition of Name in MyCommon.targets overrides the definition in MyApp.proj. If, the project is imported before the property Name is defined, the build would display the following message:

Name="MyApp"

Use the following approach when importing projects

1. Define, in the project file, all properties and items that are used as parameters for properties and items in the imported project.

2. Import the project.

3. Define in the project file all properties and items that must override default definitions of properties and items in the imported project.

Example

The following code example shows the MyCommon.targets file that the second code example imports. The .targets file evaluates properties from the importing project to configure the build.

<Project xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
    <PropertyGroup>
        <Flavor Condition="'$(Flavor)'==''">DEBUG</Flavor>
        <Optimize Condition="'$(Flavor)'=='RETAIL'">yes</Optimize>
        <appname>$(MSBuildProjectName)</appname>
    <PropertyGroup>
    <Target Name="Build">
        <Csc Sources="hello.cs"
            Optimize="$(Optimize)"
            OutputAssembly="$(appname).exe"/>
    </Target>
</Project>

The following code example imports the MyCommon.targets file.

<Project DefaultTargets="Build"
    xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
    <PropertyGroup>
        <Flavor>RETAIL</Flavor>
    </PropertyGroup>
    <Import Project="MyCommon.targets"/>
</Project>