grails-cascade-validation

This plugin establishes a cascade constraint property for validateable objects, that being domain objects, and objects implementing grails.validation.Validateable. If cascade:true is set on a nested object, the nested object's validate() method will be invoked and the results will be reported as part of the parent object's validation.

This plugin is for Grails 7.0.0

BREAKING CHANGE

The cascade constraint in constraints was renamed to cascaded because of a name clash with Hibernate cascading.

To use this plugin, add the plugin to build.gradle:

dependencies {
     implementation "io.github.gpc:cascade-validation:7.0.0"
}

Here is an example of a command object that uses the plugin:

class Person implements Validateable {
    String firstName
    String lastName
    List<PhoneNumber> phones
    
    static constraints = {
        phones cascaded: { value -> value.isPrimary } // Only validate the phonenumber if the value is a primary number
    }
}

 class PhoneNumber implements Validateable {
     long id
     String countryCode
     String areaCode
     String number
     String extension
     TelephoneType telephoneType
     boolean isPrimary

     static constraints = {
         areaCode(nullable: false)
         number(nullable: false)
         telephoneType(cascaded: true)
     }

     static class TelephoneType implements Validateable {
         String id
         boolean countryCodeRecommended

         static constraints = {
             id(nullable: false)
             countryCodeRecommended(nullable: false)
         }
     }
 }

When the cascade: constraint is added on the telephoneType property, this enables nested validation. When the phoneNumber.validate() method is called, the telephoneType.validate() method will also be invoked. Field errors that are added to the telephoneType will also be added to the parent phoneNumber object.

This plugin was originally based on a blog post by Eric Kelm and is used here with Eric's permission.

NOTE:

When running a unit test, the cascade constraint isn't registered with Grails. To work around this issue, the test class must implement org.grails.testing.GrailsUnitTest and the following code must be added to the setup() method of the test:

import grails.cascade.validation.internal.CascadeConstraintRegistration
import org.grails.datastore.gorm.validation.constraints.eval.DefaultConstraintEvaluator
import org.grails.testing.GrailsUnitTest
import spock.lang.Specification

class ParentSpec extends Specification implements GrailsUnitTest {

    Closure doWithSpring() {
        return {
            constraintEvaluator(DefaultConstraintEvaluator)
        }
    }

    void setup() {
        // Important for Unit-tests as the registrations only happens when Grails context is started.
        CascadeConstraintRegistration.register(applicationContext)
    }

    void 'validate cascade'() {
        given:
        def phone = new PhoneNumber(telephoneType: new PhoneNumber.TelephoneType())

        when:
        phone.validate(['telephoneType'])

        then:
        phone.hasErrors()

        parent.errors.getFieldError('telephoneType.id').code == 'nullable'
        parent.errors.getFieldError('telephoneType.countryCodeRecommended').code == 'nullable'
    }
}

This will register the CascadeConstraint the same way as the plugin does at runtime.

See the full documentation here: https://gpc.github.io/grails-cascade-validation/snapshot/