Functions/Test-RegistryKeyValue.ps1

# Copyright 2012 Aaron Jensen
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.

function Test-RegistryKeyValue
{
    <#
    .SYNOPSIS
    Tests if a registry value exists.
     
    .DESCRIPTION
    The usual ways for checking if a registry value exists don't handle when a value simply has an empty or null value. This function actually checks if a key has a value with a given name.
     
    .EXAMPLE
    Test-RegistryKeyValue -Path 'hklm:\Software\Carbon\Test' -Name 'Title'
     
    Returns `True` if `hklm:\Software\Carbon\Test` contains a value named 'Title'. `False` otherwise.
    #>

    [CmdletBinding()]
    param(
        [Parameter(Mandatory=$true)]
        [string]
        # The path to the registry key where the value should be set. Will be created if it doesn't exist.
        $Path,
        
        [Parameter(Mandatory=$true)]
        [string]
        # The name of the value being set.
        $Name
    )
    
    Set-StrictMode -Version 'Latest'

    Use-CallerPreference -Cmdlet $PSCmdlet -Session $ExecutionContext.SessionState

    if( -not (Test-Path -Path $Path -PathType Container) )
    {
        return $false
    }
    
    $properties = Get-ItemProperty -Path $Path 
    if( -not $properties )
    {
        return $false
    }
    
    $member = Get-Member -InputObject $properties -Name $Name
    if( $member )
    {
        return $true
    }
    else
    {
        return $false
    }
}