It is no secret that PowerCLI has lots of amazing options and well-thought trough features. But there is one feature that most of PowerCLI’s users take for granted, and most probably do not even realise that they are using what is called Object By Name or OBN. In this post I’ll show you one way of creating your own OBN, a home made Object By Name, which you can use in your own functions and modules.
OBN allows you to refer to a PowerCLI object by name, instead of passing an actual PowerCLI object. A classic example is “Get-VM -Datastore DS1“, where we are retrieving all VMs that live on a specific datastore. If one looks at the description of the Datastore parameter, it clearly states that a value of type StorageResource is expected, but we are able to provide the datastorename, a string. Under the cover, PowerCLI converts this string to the required PowerCLI object for the parameter.
When we are writing our own functions, it would be very handy to have the same functionality at our disposal. Define a parameter to be of the type of a PowerCLI object, but then be able to pass the name of the object, instead of the object itself.
The solution is here, with the MyOBN attribute. We now have the same functionality available, that was until now only available for PowerCLI cmdlets.