CODEWITHSUNDEEP
windowspowershellobjectwmi
mrkrch
mrkrch

Reputation: 13

Add-Member to WMI object best practice?

I'm writing a function for getting the Windows version using WMI object. But I wanted to add the Windows 10 ReleaseId ("1709") (from a registry key) into the object.

Is this a stupid idea? (It works, I just don't know if it's a smart thing to do.)

function Get-OSVersion {
    [version]$OSVersion = (Get-WmiObject -Class Win32_OperatingSystem).Version

    if ($OSVersion.Major -ge '10') {
        $OSVersion | Add-Member -MemberType NoteProperty -Name ReleaseId -Value $([int]::Parse($(Get-ItemProperty -Path "Registry::HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion" ReleaseId).ReleaseId)) -Force
    }

    return $OSVersion
}

$OSVersion = Get-OSVersion
if ($OSVersion -ge '6.1') {"At least Win7"} else {"Too old"}
if ($OSVersion.ReleaseID -ge '1703') {"At least 1703."} else {"Too old"}

Also, would it be unwise to overwrite the member "Revision" (value is always -1) instead of adding a new member "ReleaseId"?

Upvotes: 1

Views: 401

Answers (2)

Ansgar Wiechers
Ansgar Wiechers

Reputation: 200373

My recommendation would be to use calculated properties:

function Get-OSVersion {
    Get-WmiObject -Class Win32_OperatingSystem |
        Select-Object @{n='Version';e={[version]$_.Version}},
            @{n='ReleaseId';e={
                if (([version]$_.Version).Major -ge '10') {
                    [int](Get-ItemProperty 'HKLM:\SOFTWARE\Microsoft\Windows NT\CurrentVersion').ReleaseId
                }
            }}
}

Upvotes: 2

Maximilian Burszley
Maximilian Burszley

Reputation: 19684

To expand on my comment:

I wouldn't suggest changing a wmi class that you don't need to, but you're not doing that. I don't see anything wrong about your approach besides adding a member to a defined standard library class (System.Version) and doing a number comparison against a string.

What I would suggest doing is creating a [pscustomobject] with the members you need:

function Get-OSVersion {
    $OSVersion = [version](Get-CimInstance -ClassName Win32_OperatingSystem).Version

    if ($OSVersion.Major -ge 10) {
        [pscustomobject]@{
            Version = $OSVersion
            ReleaseId = [int](Get-ItemProperty -Path 'HKLM:\SOFTWARE\Microsoft\Windows NT\CurrentVersion').ReleaseId
        }
    } else {
        [pscustomobject]@{
            Version = $OSVersion
        }
    }
}

In use:

$OS = Get-OSVersion
if ($OS.Version -ge [version]'6.1') {
    'At least Win7'
} else {
    'Too old'
}
if ($OS.ReleaseId -ge 1703) {
    'At least 1703.'
} else {
    'Too old'
}

To serve an alternative: Use a hashtable since it looks like you're just doing key/value accessing and comparisons without any method implementation.

function Get-OSVersion {
    $OS = @{
        Version = [version](Get-CimInstance -ClassName Win32_OperatingSystem).Version
    }

    if ($OS.Version.Major -ge 10) {
        $OS['ReleaseId'] = [int](Get-ItemProperty -Path 'HKLM:\SOFTWARE\Microsoft\Windows NT\CurrentVersion').ReleaseId
    }

    return $OS
}

Upvotes: 2

Related Questions