
package net.sourceforge.pmd.lang.vm.directive;

/*
 * 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.
 */

/**
 * This class acts as a proxy for potential macros. When the AST is built this
 * class is inserted as a placeholder for the macro (whether or not the macro is
 * actually defined). At render time we check whether there is a implementation
 * for the macro call. If an implementation cannot be found the literal text is
 * rendered.
 * 
 * @since 1.6
 */
public class RuntimeMacro extends Directive {
    /**
     * Name of the macro
     */
    private String macroName;

    /**
     * Create a RuntimeMacro instance. Macro name and source template stored for
     * later use.
     *
     * @param macroName
     *            name of the macro
     */
    public RuntimeMacro(String macroName) {
        if (macroName == null) {
            throw new IllegalArgumentException("Null arguments");
        }

        this.macroName = macroName.intern();
    }

    /**
     * Return name of this Velocimacro.
     *
     * @return The name of this Velocimacro.
     */
    public String getName() {
        return macroName;
    }

    /**
     * Override to always return "macro". We don't want to use the macro name
     * here, since when writing VTL that uses the scope, we are within a #macro
     * call. The macro name will instead be used as the scope name when defining
     * the body of a BlockMacro.
     */
    public String getScopeName() {
        return "macro";
    }

    /**
     * Velocimacros are always LINE type directives.
     *
     * @return The type of this directive.
     */
    public int getType() {
        return LINE;
    }

}
