Constraints provide Grails with a declarative DSL for defining validation rules, schema generation and CRUD generation meta data. For example, consider these [code] class User { String username String password String email int age static constraints = { username size:...

Although In most of cases like doing something before each request grails provides the concept of interceptors with in a controller, but if we like to intercept request in more than one controller than grails another functionality comes into picture called Filters....

I was having a use-case where I need to use grails taglib, In this taglib I have a tag from which I need to return a map but I struggling with that as grails taglib by default return’s StreamCharBuffer e.g class ObjectReturningTagLib { static namespace =...

When an exception is generated in server responds to client with status “500” and using this response code we display a message to enduser through UrlMapping like: "500"(controller:"error", action:"display") We can customize...