DynamicParameter

Sample Provider - How to use dynamic parameters

Step 1- Install SHiPS

Follow the instructions in here to download and install the SHiPS.

Step 2 - Model the system

Let's say we want to model a tree as follows:

   Nature
         - Plant
               - Birch
               - Maple
               - Oak
         - Creature
               - Cat
               - Dog
                   - Husky
                   - Bulldog

Step 3 - Review the sample code

See the DynamicParameterSample module.

Step 4 - Try it out

   Import-Module  SHiPS
   Import-Module  .\samples\DynamicParameter

   new-psdrive -name n -psprovider SHiPS -root DynamicParameter#Nature
   cd n:
   dir

   dir -Type Plant

   dir -Type Creature

   dir -Filter p* -recurse

<#
The output looks like the following.
PS n:\>dir

Mode  Name
----  ----
+     Plant
+     Creature

PS n:\>dir -Type Plant

    Container: Microsoft.PowerShell.SHiPS\SHiPS::DynamicParameterSample#Nature

Mode  Name
----  ----
+     Plant

PS n:\> dir -Type Creature

    Container: Microsoft.PowerShell.SHiPS\SHiPS::DynamicParameterSample#Nature

Mode  Name
----  ----
+     Creature

PS n:\> cd .\Creature\
PS n:\Creature>dir -Filter p* -recurse
Pointer
Poodle
Pug
Pomeranian
Pui
Pumi

#>

Key takeaways from this example

• Other than built-in parameters in Get-ChildItem, author can add dynamic parameters

  • Define it as a class
  • Add [Parameter()] in a dynamic parameter. That's it.

• Define [object] GetChildItemDynamicParameters() method and return a instance of the class that defines your dynamic parameters

• To get whether a user specifies any dynamic parameters, you can use $this.ProviderContext.DynamicParameters.

• Filter is a built-in parameter.

Sometimes you want to have server-side search for better user experience, you can get the query string via $this.ProviderContext.Filter. The value of Filter here is foobar* from -Filter foobar*