Include Enum's from another file

Question

In my Powershell "project" I would like to have all the common Enum's in a single file and then reference that file from the various other scripts.

I've tried dot-sourcing the file, and I tried converting the Enum file to a psm1 (Import-Module), but nothing I've tried so far has worked.

For example, the Enum file datatypes.ps1 looks something like this:

Enum DataType { String, Integer, Boolean }

And I tried to include it like this:

. ".\datatypes.ps1"

class MyClass {
    [DataType]$Type = [DataType]::String
}

When I run the above I get the error message:

Unable to find type [DataType].

I've used dot-sourcing to include variables and functions before, those have always worked. But now the Enum's are refusing to work :(

Should dot-sourcing work? Should the module approach work? or must Enum's be located in the same file/script?

EDIT:

I think I might have found the problem, it seems that the script is being completely parsed before the include is being included, is that possibly the issue?

Answer 1

I believe Import-Module does not work, because it loads items in to a different context. You can use the dot sourcing or the using module statement. If you are using the latter, then you need to provide a fully path to the file or place it in one of the $env:PSModulePath paths.

If you want to import enums or classes in to a module I find the approach below works best, i.e. dot sourcing the full filenames in the module psm1 file.

Assuming a basic project layout like:

- MyModule
    |- Classes
        |- MyClasses.ps1
    |- Enums
        |- MyEnums.ps1
    |- MyModule.psm1
    |- MyModule.psd1

MyModule.psm1

if (Test-Path -Path "$PSScriptRoot\Classes") {
    $Enums = Get-ChildItem (Join-Path $PSScriptRoot Enums) -Filter *.ps1 -ErrorAction SilentlyContinue
    $Classes = Get-ChildItem (Join-Path $PSScriptRoot Classes) -Filter *.ps1 -ErrorAction SilentlyContinue

    # Order imports so that Enums are before Classes
    foreach ($Class in @($Enums;$Classes)) {
        Try {
            . $Class.FullName
            Write-Verbose -Message "Imported $($Class.BaseName)"
        }
        Catch {
            Write-Error -Message "Could not load Class [$($Class.Name)] : $($_.Message)"
        }
    }
}

# Import functions here if you have them, or do anything else.