autovars.psm1
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function new-autoVariable { param($name, [ScriptBlock] $getter, [ScriptBlock] $setter) Add-Type @” using System; using System.Collections.ObjectModel; using System.Management.Automation; namespace CodeOwls.PowerShell { public class PSScriptVariable : PSVariable { public PSScriptVariable(string name, ScriptBlock scriptGetter, ScriptBlock scriptSetter) : base(name, null, ScopedItemOptions.AllScope) { getter = scriptGetter; setter = scriptSetter; } private ScriptBlock getter; private ScriptBlock setter; public override object Value { get { if(getter != null) { Collection<PSObject> results = getter.Invoke(); if(results.Count == 1) { return results[0]; } else { PSObject[] returnResults = new PSObject[results.Count]; results.CopyTo(returnResults, 0); return returnResults; } } else { return null; } } set { if(setter != null) { setter.Invoke(value); } } } } } “@ if( $name -notmatch '.+:' ) { $name = 'global:' + $name; } if(Test-Path variable:\$name) { Remove-Item variable:\$name -Force } $executioncontext.SessionState.PSVariable.Set( (New-Object CodeOwls.PowerShell.PSScriptVariable $name,$getter,$setter)) <# .SYNOPSIS Creates a new automatic variable. .DESCRIPTION Creates a new automatic (or tied) variable. The variable value will be calculated when the variable is referenced using the supplied getter scriptblock. Unless a specific scope is specified, the variable is defined in the global scope. .EXAMPLE PS C:\ > new-autovariable -name now -getter { [datetime]::now } PS C:\ > $now Tuesday, March 26, 2013 9:27:38 PM Creates a new automatic variable named 'now' that returns the current date and time instant. .NOTES NAME: AUTHOR: beefarino LASTEDIT: 03/26/2013 21:25:22 KEYWORDS: .Link http://www.codeowls.com #> } |