001/*
002 * Licensed under the Apache License, Version 2.0 (the "License");
003 * you may not use this file except in compliance with the License.
004 * You may obtain a copy of the License at
005 *
006 * http://www.apache.org/licenses/LICENSE-2.0
007 *
008 * Unless required by applicable law or agreed to in writing, software
009 * distributed under the License is distributed on an "AS IS" BASIS,
010 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
011 * See the License for the specific language governing permissions and
012 * limitations under the License.
013 */
014
015package org.basepom.mojo.propertyhelper.macros;
016
017import org.basepom.mojo.propertyhelper.FieldContext;
018import org.basepom.mojo.propertyhelper.ValueProvider;
019import org.basepom.mojo.propertyhelper.definitions.MacroDefinition;
020
021import java.util.Optional;
022
023/**
024 * Macro implementation. All macro classes must implement this interface.
025 */
026public interface MacroType {
027
028    /**
029     * Returns the value for a specific macro invocation.
030     *
031     * @param macroDefinition The macro definition
032     * @param valueProvider A value provider that either provides a property backed value or the initial (default) value
033     * @param context The Field context
034     * @return An {@link Optional} wrapping a string value. If the macro returns {@link Optional#empty()}, the field value will be the empty string
035     */
036    Optional<String> getValue(MacroDefinition macroDefinition,
037        ValueProvider valueProvider,
038        FieldContext context);
039}