(Quick Reference)

errors

Purpose

An instance of the Spring Errors interface containing errors associated with this controller.

Examples

class DemoController {

    static allowedMethods = [updatePerson: 'PUT']

    def generateReport(int size) {
        if(hasErrors()) {
            errors.allErrors.each {
                println it
            }
        }
    }

    def updatePerson(SomeDomainClass sdc) {
        // if params.id is found then a call
        // will have been made to SomeDomainClass.get(params.id)
        // to retrieve the instance from the database.
        // if no matching instance is found then
        // sdc will be null and the controller
        // will not have errors.  If params.id
        // is found and an exception occurs while
        // trying to retrieve the instance then
        // sdc will be null and an error will
        // be added to the controller
        if(sdc == null && hasErrors()) {
            errors.allErrors.each {
                println it
            }
        }
    }
}

Description

The errors property is used by Grails while processing a request. Errors are generated when a type conversion happens while processing action parameters or if an exception is thrown while trying to retrieve a domain class command object from the database.

See hasErrors.