# requires -version 2.0

<#
 -----------------------------------------------------------------------------
 Script: Select-PropertyValue-v2.ps1
 Version: 2.0
 Author: Jeffery Hicks
    http://jdhitsolutions.com/blog
    http://twitter.com/JeffHicks
    http://www.ScriptingGeek.com
 Date: 8/12/2011
 Keywords: Object, Property, Get-Member, Select-Object
 Comments:
 
 "Those who forget to script are doomed to repeat their work."

  ****************************************************************
  * DO NOT USE IN A PRODUCTION ENVIRONMENT UNTIL YOU HAVE TESTED *
  * THOROUGHLY IN A LAB ENVIRONMENT. USE AT YOUR OWN RISK.  IF   *
  * YOU DO NOT UNDERSTAND WHAT THIS SCRIPT DOES OR HOW IT WORKS, *
  * DO NOT USE IT OUTSIDE OF A SECURE, TEST SETTING.             *
  ****************************************************************
 -----------------------------------------------------------------------------
 #>
 
Function Select-PropertyValue {

<#
.SYNOPSIS
Select only object properties with values.
.DESCRIPTION
Using an expression like:  get-process PowerShell | select * is a handy way to see all properties 
and their values. But sometimes you may only want to see properties that have actual values. For
those situations, use this function. This function can be used in a pipelined expression to return 
all properties of a given object that have a defined value. 

 get-process PowerShell | Select-PropertyValue
 
When looking at WMI objects you can use -NoSystem to filter out WMI system properties like __PATH.

The function assumes that all input objects are of the same type.
.PARAMETER InputObject
The pipelined object.
.PARAMETER NoSystem
Filter out system properties for WMI objects like __PATH
.PARAMETER Inquire
When used in conjuction with -Debug, sets the debug preference to Inquire which will prompt
you for each line. If you use -Debug alone then you'll get all the debug messages, but no
prompting.
.EXAMPLE
PS C:\> get-service | select-propertyvalue

CanStop       : True
DisplayName   : Application Experience
MachineName   : .
Name          : AeLookupSvc
ServiceHandle : SafeServiceHandle
ServiceName   : AeLookupSvc
ServiceType   : Win32ShareProcess
Status        : Running
Type          : System.ServiceProcess.ServiceController

DisplayName   : Application Layer Gateway Service
MachineName   : .
Name          : ALG
ServiceHandle : SafeServiceHandle
ServiceName   : ALG
ServiceType   : Win32OwnProcess
Status        : Stopped
Type          : System.ServiceProcess.ServiceController

DisplayName        : Application Identity
MachineName        : .
Name               : AppIDSvc
RequiredServices   : {CryptSvc, RpcSs, AppID}
ServiceHandle      : SafeServiceHandle
ServiceName        : AppIDSvc
ServicesDependedOn : {CryptSvc, RpcSs, AppID}
ServiceType        : Win32ShareProcess
Status             : Stopped
Type               : System.ServiceProcess.ServiceController
...

Get only populated properties for the service object.
.EXAMPLE
PS C:\> get-wmiobject win32_bios | select-propertyvalue -nosystem

BiosCharacteristics  : {4, 7, 8, 9...}
BIOSVersion          : {TOSQCI - 6040000, Ver 1.00PARTTBL}
Caption              : Ver 1.00PARTTBL
Description          : Ver 1.00PARTTBL
Manufacturer         : TOSHIBA
Name                 : Ver 1.00PARTTBL
PrimaryBIOS          : True
ReleaseDate          : 20101210000000.000000+000
SerialNumber         : Z9131790W
SMBIOSBIOSVersion    : V2.90
SMBIOSMajorVersion   : 2
SMBIOSMinorVersion   : 6
SMBIOSPresent        : True
SoftwareElementID    : Ver 1.00PARTTBL
SoftwareElementState : 3
Status               : OK
Version              : TOSQCI - 6040000
Type                 : System.Management.ManagementObject#root\cimv2\Win32_BIOS

Get all populated properties for the WMI object, filtering out system properties.
.NOTES
NAME        :  Select-PropertyValue
VERSION     :  2.0   
LAST UPDATED:  8/12/2011
AUTHOR      :  Jeffery Hicks
.LINK
http://jdhitsolutions.com/blog/2011/08/select-object-properties-with-values
.LINK
Get-Member 
Select-Object 
.INPUTS
Any object
.OUTPUTS
A custom object
#>

[cmdletbinding()]

Param(
[Parameter(Position=0,ValueFromPipeline=$True)]
[object]$InputObject,
[Switch]$NoSystem,
[Switch]$Inquire = $False
)

Begin { 
  Write-Verbose "Starting $($myinvocation.mycommand)" 
  
  #define a variable we will be using to keep StrictMode happy.
  $properties=@()
} #begin
 
Process {

 <#
  set debug preference to continue when using -Debug unless user
  has also used -Inquire. Otherwise, PowerShell will prompt
  for each command. Due to scoping issues I found the best solution
  was to set the debug preference for each object in the pipeline
  #>
  
  if (($PSCmdlet.MyInvocation.BoundParameters.ContainsKey("debug")) -AND (-NOT $Inquire)) {
      $DebugPreference="Continue"
  }

Write-Debug "In process"
Write-Debug "Checking for `$properties"
<#
because this only takes pipelined objects, we only need to get the properties from 
Get-Member once. When the second object is processed, this IF block will get skipped.
The assumption that all pipelined objects are of the same type.
#>

if (-Not $properties) {
    Write-Verbose "Creating property list"
    Write-Debug "Creating property list for pipelined object"
    
    #get properties for the pipelined object sorted by property name
    $properties=$_ | Get-Member -membertype Properties | sort Name
    $typename=($_ |Get-Member)[0].TypeName
    Write-Debug "Typename =$typename"
    
    #filter out WMI System properties if -NoSystem
    if ($NoSystem) {
        Write-Verbose "Filtering out WMI System properties"
        Write-Debug "Filtering out WMI System properties."
        $properties=$properties | where {$_.name -notlike "__*"}
    }
    
    Write-Verbose "Found $($properties.count) properties"
    Write-Debug "Found $($properties.count) properties"
}

 #create an empty custom object
 Write-Debug "Creating empty object"
 $obj=New-Object PSObject

#enumerate the list of properties
Write-Verbose "Checking properties for values"
foreach ($property in $properties) { 
    Write-Debug "Checking $($property.name)"
     #if object has a value for the current property
     if ($_.($property.name)) {       
        Write-Debug "found value for: $($_.($property.name))"
        
        #assign properties to the custom object
        Write-Debug "Adding property and value to custom object"
        $obj | Add-Member -MemberType Noteproperty -name $property.Name -value ($_.($property.name))
             
     } #end If
} #end ForEach

#Add the typename to the object
Write-Debug "Adding typename to custom object"
$obj | Add-Member -MemberType Noteproperty -Name "Type" -Value $typename

#write the custom object to the pipeline
Write-Debug "Writing custom object to the pipeline"
Write $obj
} #end process
 
End {
  Write-Verbose "Ending $($myinvocation.mycommand)" 
 }

} #end function

#define an optional alias
#Set-Alias -Name spv -value Select-PropertyValue