winsw/doc/extensions/extensions.md

WinSW extensions
===

Starting from WinSW `2.0`, the wrapper provides an internal extension engine and several extensions.
These extensions allow to alter the behavior of the Windows service in order to setup the required service environment.

### Available extensions

* [Shared Directory Mapper](sharedDirectoryMapper.md) - Allows mapping shared drives before starting the executable
* [Runaway Process Killer](runawayProcessKiller.md) - Termination of processes started by the previous runs of WinSW

### Developer guide

In WinSW `2.x` the extension does not support inclusion of external extension DLLs.

#### Adding external extensions

The only way to create an external extension is to create a new extension DLL and 
  then to merge this DLL into the executable using tools like `ILMerge`.
See the example in `src/Core/ServiceWrapper/winsw.csproj`.

Generic extension creation guideline:
* Extension DLL should reference the `WinSWCore` library.
* The extension should extend the `AbstractWinSWExtension` class.
* The extension then can override event handlers offered by the upper class.
* The extension should implement the configuration parsing from the `XmlNode`.
* The extension should support disabling from the configuration file.

WinSW engine will automatically locate your extension using the class name in the [XML Configuration File](../xmlConfigFile.md).
See configuration samples provided for the extensions in the core.
For extensions from external DLLs, the `className` field should also specify the assembly name. 
It can be done via fully qualified class name or just by the `${CLASS_NAME}, ${ASSEMBLY_NAME}` declaration.

Please note that in the current versions of WinSW `2.x` the binary compatibility of extension APIs *is not guaranteed*.