001    // Copyright 2010 The Apache Software Foundation
002    //
003    // Licensed under the Apache License, Version 2.0 (the "License");
004    // you may not use this file except in compliance with the License.
005    // You may obtain a copy of the License at
006    //
007    // http://www.apache.org/licenses/LICENSE-2.0
008    //
009    // Unless required by applicable law or agreed to in writing, software
010    // distributed under the License is distributed on an "AS IS" BASIS,
011    // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
012    // See the License for the specific language governing permissions and
013    // limitations under the License.
014    
015    package org.apache.tapestry5.validator;
016    
017    import org.apache.tapestry5.ioc.annotations.UsesMappedConfiguration;
018    
019    /**
020     * Allows support for "validator macros", a simple-minded way of combining several related valiations together under
021     * a single name. The service's configuration maps string keys (macro names) to string values (validation constraints).
022     * 
023     * @since 5.2.0
024     */
025    @UsesMappedConfiguration(String.class)
026    public interface ValidatorMacro
027    {
028        /**
029         * Given a <em>potential</em> validator macro (a simple string name), returns the value for that macro, a
030         * comma-separated list of validation constraints.
031         * 
032         * @return constraints, or null if no such validator macro
033         */
034        String valueForMacro(String validatorMacro);
035    }