/// <summary>
/// processes the new-item cmdlet for paths that resolve to the appdomain value factory
///
/// adds an assembly to the current appdomain. assemblies can be specified using
/// their (partial) names or a file path.
///
/// this implementation essentially delegates all work to to the add-type built-in
/// powershell cmdlet to load an assembly from a partial name or file path.
/// </summary>
/// <param name="providerContext">the cmdlet providerContext providing powershell and framework services</param>
/// <param name="path">the relative path supplied to the new-item cmdlet, either as the child element of the -path parameter, or the value of the -name parameter</param>
/// <param name="itemTypeName">the type of the item to create; unused in this value</param>
/// <param name="newItemValue">the value of the new item to create; unused in this value</param>
/// <returns></returns>
public IPathValue NewItem(IProviderContext providerContext, string path, string itemTypeName, object newItemValue)
{
IEnumerable<PSObject> results = new PSObject[]{};
// first try to load the new assembly from an assembly name
// note that the invoked script will return a single assembly object if successful
try
{
results = providerContext.InvokeCommand.InvokeScript(
String.Format("add-type -assemblyname '{0}' -passthru | select -first 1 -exp Assembly", path),
null);
}
catch
{
}
// ... if that fails, try and load the assembly from a file path
// note that the invoked script will return a single assembly object if successful
if( ! results.Any() )
{
try
{
results = providerContext.InvokeCommand.InvokeScript(
String.Format("add-type -path '{0}' -passthru | select -first 1 -exp Assembly", path),
null);
}
catch
{
}
}
// raise any errors
if( ! results.Any() )
{
throw new ArgumentException( "the specified name is not recognized as a valid assembly name or path");
}
// return the path value value to write to the pipeline
var assembly = results.First().BaseObject as Assembly;
// to maintain consistency I find it easier to leverage the value factory classes rather than return
// an IPathValue instance directly.
var nodeFactory = new AssemblyPathNode(assembly);
return nodeFactory.GetNodeValue();
}
