Private/Test-FPControlSource.ps1

function Test-FPControlSource {
    <#
    .SYNOPSIS
        Validate File or URI is accessible
    .DESCRIPTION
        Verifies Control XML file is accessible
    .PARAMETER Path
        Full Path or URI to file
    .INPUTS
        Path to file
    .OUTPUTS
        $True or $null
    #>

        param (
            [parameter(Mandatory = $True)]
            [ValidateNotNullOrEmpty()]
            [string] $Path
        )
        if ($Path.StartsWith('http')) {
            Write-FPLog "verifying URI resource: $Path"
            try {
                $test = Invoke-WebRequest -UseBasicParsing -Uri $Path -Method Get -ErrorAction SilentlyContinue
                if ($test) {
                    Write-Output ($test.StatusCode -eq 200)
                }
            }
            catch {}
        }
        else {
            Write-FPLog "verifying file system resource: $Path"
            Write-Output (Test-Path $Path)
        }
}