Unique Object Field Lookup

[Andrew Burger]

I am trying to build a request form for new server builds and I need to do a field lookup to vmware to ensure the VM name is not in use when a customer puts in a suggested server name. (forget for a moment that we allow people to choose their own server names in the first place)

Further validation with DNS and Active Directory will be done in the code for deployment, but this gets at least one of the checks complete and is a pretty solid check on name uniqueness.  Is this possible?  I believe it is probably some sort of post function check to the VMware API but I think I need a little more of a nudge in the right direction to validate this.

[Nic Brough -Adaptavist-]

A post-function is too late, it won't stop the user committing the new issue with the wrong data.  (Well, you can, if you deliberately crash the process, but that's a bad bad thing to do, as it loses all the input data and gives the user a crash message)

Use a validator - these return either "yes" or "no, and here's an error message".  The "no" will return the user to the create screen with all their data entered, so they can try again.