Question

Imagine I have this scenario in my Controller:

def nr_1 = params.first_nr
def nr_2 = params.second_nr
def result
def erro = 'no'

if(nr_1.isInteger() && nr_2.isInteger())
    result = nr_1.toInteger() * nr_2.toInteger()
else
    erro = 'yes'

if(erro.equals('yes'))
    [sms : 'Please introduce only 2 numbers!']
else
    [sms: 'The result of the multiplication of ' + nr_1 + ' with ' + nr_2 + ' is ' + result]

This is returned to my gsp view and it is successfully done. Now I want to transform this into a REST access Web Service. The way im seeing this, I’ll have to manually create the tags like this:

<firstNumber>nr_1</firstNumber>
<secondNumber>nr_1</secondNumber>   
<result>result</result>  

and then return to the rest request. How can I accomplish this (By providing both HTML and XML response, and for XML, parse only the last XML tags).

Answer 1

You can create an object that represent your request and put the content of your request in it.

class Multiplication
{
  String nr_1
  String nr_2
  String result
}

It will enable you to us render as XML to generate your XML in your action:

def multiplication = new Multiplication(nr_1: params.first_nr,
                                        nr_2: params.second_nr)
def error = 'no'
  if (multiplication.nr_1.isInteger() && multiplication.nr_2.isInteger())
    multiplication['result'] = multiplication.nr_1.toInteger() * multiplication.nr_2.toInteger()
  else
    error = 'yes'

if (error == 'yes')
{
  [sms: 'Please introduce only 2 numbers!']
}
withFormat {
  html sms: "The result of the multiplication of $multiplication.nr_1 with $multiplication.nr_2 is $multiplication.result"
  xml { render multiplication as XML }
}

Don’t forget to import grails.converters.* at the beginning of your controller.