Get Deriving Types Visual Studio

####################################################
# 1: Save as DemoModule.psm1
# 2: In Visual Studio, open package manager console
#   2.1: Register: Import-Module "C:\pathtomodule\DemoModule.psm1"
# 3: Usage (will list all classes in DemoProject that derives BaseEntity and print the names):
#   Get-DerivingTypes DemoProject BaseEntity| ForEach{$_.Name}
# 4: Usage (Will look in all projects in the solution)
#   (Get-Project -All) | ForEach{Get-DerivingTypes $_.ProjectName PersistentEntity | ForEach{$_.Name}}
#
# Tips: Use tab to get projectnames automatically...
#
# To Remove: Remove-Module DemoModule
####################################################
$global:files = $null
function Get-AllFiles{
    param(
        [parameter(ValueFromPipelineByPropertyName = $true)][string[]]$ProjectName
    )
    # Set the global of files
    $global:files = @()
    Recurse-Project $ProjectName -Action {param($item)
        # ForEach file found in the project... add to list of files
        if($item.Type -eq 'File'){
            $global:files += $item
        }
    }

    return $global:files
}

function Get-DerivingTypes{
    param(
        [parameter(ValueFromPipelineByPropertyName = $true)][string[]]$ProjectName,
        [parameter(ValueFromPipelineByPropertyName = $true)][string[]]$TypeName
    )

    # Get files in the selected project
    $allfiles = Get-AllFiles $ProjectName

    $types = @()
    # Extract all namespaces
    $namespaces = $allfiles | ForEach{$_.ProjectItem.FileCodeModel.CodeElements | Where-Object{$_.Kind -eq 5}}

    # Extract all children in all namespaces
    $codeelements = $namespaces | ForEach{$_.Children}

    # Add types deriving your input type to the list of types.
    $codeelements | ForEach{
        $current = $_
        $_.Bases | ForEach{
            if($_.Name -eq $TypeName){
                $types += $current
            }
        }
    }
    return $types
}

function Recurse-Project {
    param(
        [parameter(ValueFromPipelineByPropertyName = $true)]
        [string[]]$ProjectName,
        [parameter(Mandatory = $true)]$Action
    )
    Process {
        # Convert project item guid into friendly name
        function Get-Type($kind) {
            switch($kind) {
                '{6BB5F8EE-4483-11D3-8BCF-00C04F8EC28C}' { 'File' }
                '{6BB5F8EF-4483-11D3-8BCF-00C04F8EC28C}' { 'Folder' }
                default { $kind }
            }
        }

        # Convert language guid to friendly name
        function Get-Language($item) {
            if(!$item.FileCodeModel) {
                return $null
            }

            $kind = $item.FileCodeModel.Language
            switch($kind) {
                '{B5E9BD34-6D3E-4B5D-925E-8A43B79820B4}' { 'C#' }
                '{B5E9BD33-6D3E-4B5D-925E-8A43B79820B4}' { 'VB' }
                default { $kind }
            }
        }

        # Walk over all project items running the action on each
        function Recurse-ProjectItems($projectItems, $action) {
            $projectItems | %{
                $obj = New-Object PSObject -Property @{
                    ProjectItem = $_
                    Type = Get-Type $_.Kind
                    Language = Get-Language $_
                }

                & $action $obj

                if($_.ProjectItems) {
                    Recurse-ProjectItems $_.ProjectItems $action
                }
            }
        }

        if($ProjectName) {
            $p = Get-Project $ProjectName
        }
        else {
            $p = Get-Project
        }

        $p | %{ Recurse-ProjectItems $_.ProjectItems $Action }
    }
}

Register-TabExpansion 'Get-DerivingTypes' @{
    ProjectName = { Get-Project -All | Select -ExpandProperty Name }
    TypeName = {"PersistentEntity"}
}

Export-ModuleMember Get-DerivingTypes