The Plug-in Manifest Generator

The section describes how plug-in projects are built and how the plug-in manifest is generated.

Plug-in Manifest Generator

The purpose of the plug-in manifest is to avoid loading all the plug-in assemblies at runtime and reflecting over them to discover the available extensions, which would affect startup performance, an important aspect of desktop applications.

The plug-in manifest generator is implemented as an MSBuild task, which runs as part of the standard Microsoft Visual Studio 2022 build. This build task is contained in Sdl.Core.PluginFramework.Build package that needs to be refreneced by the project.

<Project xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
  <UsingTask TaskName="Sdl.Core.PluginFramework.Build.CreatePluginManifestTask" AssemblyFile="Sdl.Core.PluginFramework.BuildTasks.dll" />

  <Target Name="GeneratePluginManifestTarget" AfterTargets="AfterBuild">
    <CreatePluginManifestTask
      ProjectDirectory="$(ProjectDir)"
      AssemblyFilePath="$(TargetPath)"
      PluginResxFilePath="$(ProjectDir)PluginResources.resx"
      ReferenceCopyLocalPaths="@(ReferenceCopyLocalPaths)"
      ReferenceSatellitePaths="@(ReferenceSatellitePaths)"
      CreatePluginPackage="$(CreatePluginPackage)"
      DeployPluginPackage="$(DeployPluginPackage)"
      PluginDeploymentPath="$(PluginDeploymentPath)"
      />
  </Target>
</Project>

This task will use .Net reflection to enumerate all the types in the assembly and identify types that are annotated with an attribute deriving from ExtensionAttribute, i.e. the extensions. It will write the type name of the extensions accompanied by the serialized extension attribute to the plug-in manifest file, which is created in a "plugins" subfolder of the project output folder and is named ASSEMBLYNAME.plugin.xml.

On top of creating the plug-in manifest, the task will also create .Net resource files for resources defined in the PluginResources.resx file. This resource file contains all strings and images referred to by extension attribute declarations in the plug-in assembly. When multiple language version of the PluginResources.resx file are present, it the task will also create resource files for those, all in the "plugins" folder.

The CreatePluginManifestTask also performs validation of the extension attribute declarations, checking for instance whether a value has been specified for all required properties and whether the all extensions implement the interface imposed by the extension point they are targeting. See also Compile-time Validation.

When creating a plug-in project using the project template from the SDK, the project file will contain the following pieces of custom content:

  • CreatePluginPackage - if set to true will generate the *.sdlplugin
  • PluginDeploymentPath - path to the root folder where the Packages and Unpacked folders are present, default path is set to %AppData%\Trados\Trados Studio\17\Plugins\Packages\