ExtJS 4 Form: Unique Field Value Validation Example (Server Validation)

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.

Output:

Source code available on GitHub

Happy Coding!