content: /*
   *  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.causeway.core.metamodel.interactions;
  
  import org.apache.causeway.core.metamodel.facetapi.Facet;
  import org.apache.causeway.core.metamodel.facetapi.FacetAbstract.Validating;
  import org.apache.causeway.core.metamodel.interactions.val.ValidityContext;
  
  /**
   * Mix-in interface for {@link Facet}s that can advise as to whether a proposed
   * value is valid.
   * <p>
   * For example, <tt>MaxLengthFacet</tt> does constrain the length of candidate
   * values, whereas <tt>DebugFacet</tt> or <tt>MemberOrderFacet</tt> do not -
   * they are basically just UI hints.
   *
   * @see DisablingInteractionAdvisor
   * @see HidingInteractionAdvisor
   */
  public interface ValidatingInteractionAdvisor extends InteractionAdvisorFacet, Validating {
  
      /**
       * Whether the validation represented by this facet passes or fails.
       * <p>
       * Implementations should use the provided {@link ValidityContext} to
       * determine whether they declare the interaction invalid. They must however
       * guard against a <tt>null</tt> {@link ValidityContext#target()}
       * is not guaranteed to be populated.
       */
      String invalidates(ValidityContext ic);
  }
  