Grails Create Criteria | Grails CreateCriteria | Custom Criteria | Custom Criteria Condition

Grails Create Criteria | Grails CreateCriteria | Custom Criteria | Custom Criteria Condition

You have to create a groovy class as below:

import org.hibernate.Criteria
import org.hibernate.HibernateException
import org.hibernate.criterion.CriteriaQuery
import org.hibernate.criterion.Criterion
import org.hibernate.engine.spi.TypedValue
import org.hibernate.internal.util.StringHelper

/**
 * Created by pritom on 25/09/2017.
 */
class CustomCriteria implements Criterion {
    private static final TypedValue[] NO_VALUES = new TypedValue[0]
    private final String propertyName

    CustomCriteria(String propertyName) {
        this.propertyName = propertyName
    }

    public String toSqlString(Criteria criteria, CriteriaQuery criteriaQuery) throws HibernateException {
        String[] columns = criteriaQuery.findColumns(this.propertyName, criteria)
        String result = StringHelper.join(" or ", StringHelper.suffix(columns, " is not null"))
        if(columns.length > 1) {
            result = '(' + result + ')'
        }

        return result
    }

    public TypedValue[] getTypedValues(Criteria criteria, CriteriaQuery criteriaQuery) throws HibernateException {
        return NO_VALUES
    }

    public String toString() {
        return this.propertyName + " is not null"
    }
}

Then you to attach those functions as below:

Object.metaClass.with {
    customCriteria = {
        String propertyName = delegate.delegate.calculatePropertyName(it)
        delegate.delegate.addToCriteria(new CustomCriteria(propertyName))
        return delegate.delegate
    }
}

Then you can use your custom criteria function as below:

return (List<Home>) Home.createCriteria().list {
    setResultTransformer(Criteria.DISTINCT_ROOT_ENTITY)
    createAlias("childs", "childs")
    isNotNull("childs.id")
    customCriteria("childs.id")
    not { isNull("childs.id") }
}