(Quick Reference)



An instance of the Spring Errors interface containing data binding and/or validation errors.


def user = new User(params)

if (user.validate()) {
    // do something with user
else {
    user.errors.allErrors.each {
        println it


The errors property is used by Grails during data binding to store type conversion errors and during validation when calling the validate or save methods.

You can also add your own errors using the reject and rejectValue methods:

if (params.password != params.confirm_password) {

        ['password', 'class User'] as Object[],
        '[Property [{0}] of class [{1}] does not match confirmation]')

    // The following helps with field highlighting in your view

    render(view: 'signup', model: [user: user])

In the example of reject above, 'user.password.doesnotmatch', is the error code corresponding to a value in grails-app/i18n/message.properties, \['password', 'class User'\] as Object\[\] is a Groovy cast from a List to an Object array to match the expected signature, and '\[Property \[{0}\] of class \[{1}\] does not match confirmation\]' is the default mapping string.

In the rejectValue example, 'password' is the field in the view to highlight using a <g:hasErrors> tag and 'user.password.doesnotmatch' is the i18n error code.