# taken from: http://troyvssharepoint.blogspot.com/2012/08/faking-spcontext-in-powershell.html

function Ensure-HttpContext([string]$url)
{
    $sw = New-Object System.IO.StringWriter
    $resp = New-Object System.Web.HttpResponse $sw
    $req = New-Object System.Web.HttpRequest "", $url, ""
    $htc = New-Object System.Web.HttpContext $req, $resp
    [System.Web.HttpContext]::Current = $htc
}

function Ensure-SPContext([string]$url)
{
    Ensure-HttpContext $url
 
    if(![System.Web.HttpContext]::Current.Items["HttpHandlerSPWeb"] -or
     ![System.Web.HttpContext]::Current.Items["HttpHandlerSPSite"])
    {
        [Microsoft.SharePoint.SPWeb]$web = Get-SPWeb $url
        [System.Web.HttpContext]::Current.Items["HttpHandlerSPWeb"] = $web
        [System.Web.HttpContext]::Current.Items["HttpHandlerSPSite"] = $web.Site
    }
}