PowerShell Dynamic Parameter Values

This repo contains the example code for the PowerShell Dynamic Parameter blog posts. All of these run on PowerShell v5 on Windows and PowerShell v6 (Core) on Windows and Linux.

In Part 1 I show how to use the DynamicParam keyword of PowerShell.

In Part 2 I show how to use Register-ArgumentCompleter to add tab completion values to your own or anyone else's commands.

Using /Part1-DynamicParam Example Code

This folder contains the progression of a Get-Animal function discussed Part 1. It uses a dynamic [ValidateSet] to allow tab completion, and restriction of values on-the-fly.

Import-Module .\Get-Animals.psm1 will import all the examples for you to run, or you can dot-source any file.

Invoke-Pester will run test to test the valid values for the sets.

Using /Part2-TabCompletion Example Code

This folder has example code to do dynamic tab completion for a set of functions that use metadata from SQL Server, as discussed in Part 2. These depend on the PowerShell SQLServer module and the Pester tests require the Northwind database

Import-Module .\RegisterArgumentCompleter.psm1 will import all the SQL Server examples. Invoke-Pester will run some tests to make sure SQL Server returns values from the Northwind database

On WSL (Windows Subsystem for Linux) or non-Windows, make sure TCP is enabled for SQL Server. In those cases you'll probably also have to call Set-SQLCredential to set the credentials for the tab completion. Running on WSL using a local SQL Server I used these commands

ipmo ./RegisterArgumentCompleter.psm1
Set-SQLCredential -Username sa -Password .....
Invoke-Pester

Localhost is the default server/instance for all queries, but you can override with a -ServerInstance parameter.

Get-SQLTable -ServerInstance .\sqlexpress

. .\RegisterOtherArgumentCompleters.ps1 will register tab completion on built in commands: a function (Get-InstalledModule), cmdlet (Get-Host), and native command (git.exe). This works on Windows and Linux.