/*
* Licensed to the Apache Software Foundation (ASF) under one
* or more contributor license agreements. See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership. The ASF licenses this file
* to you under the Apache License, Version 2.0 (the
* "License"); you may not use this file except in compliance
* with the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing,
* software distributed under the License is distributed on an
* "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
* KIND, either express or implied. See the License for the
* specific language governing permissions and limitations
* under the License.
*/
package org.apache.isis.core.metamodel.facets.object.validating.validateobject;
import org.apache.isis.core.metamodel.adapter.ObjectAdapter;
import org.apache.isis.core.metamodel.facetapi.Facet;
import org.apache.isis.core.metamodel.facets.object.callbacks.PersistingCallbackFacet;
import org.apache.isis.core.metamodel.facets.object.callbacks.UpdatingCallbackFacet;
import org.apache.isis.core.metamodel.interactions.ValidatingInteractionAdvisor;
/**
* Mechanism for determining whether this object is in a valid state, for
* example so that it can be persisted or updated.
*
* <p>
* Even though all the properties of an object may themselves be valid, there
* could be inter-property dependencies which are invalid. For example
* <tt>fromDate</tt> > <tt>toDate</tt> would probably represent an invalid
* state.
*
* <p>
* In the standard Apache Isis Programming Model, typically corresponds to the
* <tt>validate</tt> method.
*
* @see PersistingCallbackFacet
* @see UpdatingCallbackFacet
*/
public interface ValidateObjectFacet extends Facet, ValidatingInteractionAdvisor {
/**
* The reason the object is invalid.
*
* <p>
* . If the object is actually valid, should return <tt>null</tt>.
*/
public String invalidReason(ObjectAdapter adapter);
}