Today’s example is an ExtJS 4 Form unique field value validation, done on the server side. Do you know when you are going to register in a new social network and you have to choose a username (and this username must be unique)? This is the case we are going to handle in this article.

I also implemented this example using Sencha Architect 2.

Final result:

Demo: http://loiane.com.br/sencha-extjs4-examples-architect/extras/UniqueFieldValidation/app.html

Source Code: https://github.com/loiane/sencha-extjs4-examples-architect/tree/master/extras/UniqueFieldValidation