Move MSBuild logic across targets

- Move Package properties from props to targets
  Include only when the project is packable.

- Move the T4 MSBuild logic to a new file and generalize them
  so any project can use it just by including the targets file.

Author: Nirmal4G

CommunityToolkit.Diagnostics/CommunityToolkit.Diagnostics.csproj

@@ -41,24 +41,6 @@
     </When>
   </Choose>
 
-  <!-- T4 service used by the Guard APIs -->
-  <ItemGroup>
-    <Service Include="{508349b6-6b84-4df5-91f0-309beebad82d}" />
-  </ItemGroup>
-
-  <ItemGroup>
-    <None Update="Generated\*.tt">
-      <Generator>TextTemplatingFileGenerator</Generator>
-      <LastGenOutput>%(Filename).g.cs</LastGenOutput>
-    </None>
-  </ItemGroup>
-
-  <ItemGroup>
-    <Compile Update="Generated\*.g.cs">
-      <DesignTime>True</DesignTime>
-      <AutoGen>True</AutoGen>
-      <DependentUpon>$([System.IO.Path]::ChangeExtension(%(Filename), '.tt'))</DependentUpon>
-    </Compile>
-  </ItemGroup>
+  <Import Project="$(BuildToolsDirectory)Community.Toolkit.TextTemplates.targets" />
 
 </Project>

build/Community.Toolkit.Common.props

@@ -1,18 +1,5 @@
 <Project>
 
-  <PropertyGroup>
-    <Company>Microsoft</Company>
-    <Authors>Microsoft</Authors>
-    <Product>.NET Community Toolkit</Product>
-    <CommonTags>.NET;Community;Toolkit;dotnet</CommonTags>
-    <PackageLicenseExpression>MIT</PackageLicenseExpression>
-    <PackageRequireLicenseAcceptance>true</PackageRequireLicenseAcceptance>
-    <Copyright>(c) .NET Foundation and Contributors. All rights reserved.</Copyright>
-    <PackageProjectUrl>https://github.com/CommunityToolkit/dotnet</PackageProjectUrl>
-    <PackageReleaseNotes>https://github.com/CommunityToolkit/dotnet/releases</PackageReleaseNotes>
-    <PackageIcon>Icon.png</PackageIcon>
-  </PropertyGroup>
-
   <PropertyGroup>
     <Nullable>Enable</Nullable>
     <LangVersion>10.0</LangVersion>

build/Community.Toolkit.Common.targets

@@ -1,5 +1,18 @@
 <Project>
 
+  <PropertyGroup Condition="$(IsPackable)">
+    <Company>Microsoft</Company>
+    <Authors>Microsoft</Authors>
+    <Product>.NET Community Toolkit</Product>
+    <CommonTags>.NET;Community;Toolkit;dotnet</CommonTags>
+    <PackageLicenseExpression>MIT</PackageLicenseExpression>
+    <PackageRequireLicenseAcceptance>true</PackageRequireLicenseAcceptance>
+    <Copyright>(c) .NET Foundation and Contributors. All rights reserved.</Copyright>
+    <PackageProjectUrl>https://github.com/CommunityToolkit/dotnet</PackageProjectUrl>
+    <PackageReleaseNotes>https://github.com/CommunityToolkit/dotnet/releases</PackageReleaseNotes>
+    <PackageIcon>Icon.png</PackageIcon>
+  </PropertyGroup>
+
   <PropertyGroup Condition="$(IsPackable)">
     <!-- TODO: Dynamically generate Title if one wasn't set -->
     <Title Condition="'$(Title)' == ''">$(Product) Asset</Title>

build/Community.Toolkit.TextTemplates.targets

@@ -0,0 +1,25 @@
+<Project>
+
+  <!-- T4 text template service used by the Visual Studio project system -->
+  <ItemGroup>
+    <Service Include="{508349b6-6b84-4df5-91f0-309beebad82d}" />
+  </ItemGroup>
+
+  <!-- Using T4 text templates to generate sources -->
+  <ItemGroup>
+    <None Update="**\*.tt">
+      <Generator>TextTemplatingFileGenerator</Generator>
+      <LastGenOutput>%(Filename).g.cs</LastGenOutput>
+    </None>
+  </ItemGroup>
+
+  <!-- Sources generated based on the above text templates -->
+  <ItemGroup>
+    <Compile Update="**\*.g.cs">
+      <AutoGen>True</AutoGen>
+      <DesignTime>True</DesignTime>
+      <DependentUpon>$([System.IO.Path]::ChangeExtension(%(Filename), '.tt'))</DependentUpon>
+    </Compile>
+  </ItemGroup>
+
+</Project>