Grails controllers repeated code for all actions - grails

Question

Imagine this controller:
class exampleController{
def action1 = {}
def action2 = {}
def action3 = {}
def action4 = {}
def action5 = {}
}
I want to be able to return in all the action in this controller the same params. Imagining this:
def user = session.user
[user: user]
Is there any way of doing this, besides writing all the same code on all the actions? The session.user return params is just an example. I don't wanna really return it.

Answer 1

A simple solution is to put this code in a method and call it from each action
class exampleController{
def action1 = {getModel()}
def action2 = {getModel()}
def action3 = {getModel()}
def action4 = {getModel()}
def action5 = {getModel()}
private getModel() {
def user = session.user
[user: user]
}
}
While this does involve some amount of repetition (invocation of the same method), it's a lot more obvious what's happening here. When debugging/testing a controller it's easy to forget about filters and interceptors, which can often lead to questions like
what the #**% is going on here?

Answer 2

Use a filter - http://grails.org/doc/latest/guide/6.%20The%20Web%20Layer.html#6.6%20Filters - or an after interceptor - http://grails.org/doc/latest/guide/6.%20The%20Web%20Layer.html#6.1.5%20Controller%20Interceptors

Answer 3

I have a similar case, and I was modified the grails scaffolding for the controller's generator.
class MyClassController {
def list = {
...
}
def show = {
def eInstance = beanIfExist()
...
}
def edit = {
def eInstance = beanIfExist()
...
}
def update = {
def eInstance = beanIfExist()
...
}
def delete = {
def eInstance = beanIfExist()
...
}
def beanIfExist = {
def beanInstance = MyClass.get(params.id)
if (beanInstance) {
return beanInstance
} else {
flash.message = "Error, invalid record."
redirect(action: "list")
return null
}
}
}
It is my suggestion, now if do you need another that sent a data to view then you can use interceptors.