So, I'm trying to understand which of the following is the best UX for a web application (not a web site). The area of the application I'm considering is the administration side of the app responsible for configuration.
So, I have a complex form with an update button. Consider the following:
The update button is locked until the form is correctly filled in or if the user cannot edit the content.
If the user can update the content of the form, the update button can be clicked at any time.
When the users clicks the button if the form isnt filled in correctly a message is displayed to the user informing them WHY they cannot submit their changes.
If the content of the form is readonly for a particular user, the data isnt displayed as a form and the update/cancel buttons are not rendered.