tapestry/tapestry-framework/src/java/org/apache/tapestry/script/ScriptParser.java

// Copyright 2004, 2005 The Apache Software Foundation
//
// Licensed 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.tapestry.script;

import org.apache.hivemind.ClassResolver;
import org.apache.hivemind.Resource;
import org.apache.tapestry.IScript;
import org.apache.tapestry.coerce.ValueConverter;
import org.apache.tapestry.services.ExpressionEvaluator;
import org.apache.tapestry.util.xml.RuleDirectedParser;

/**
 * Parses a Tapestry Script, an XML file defined by one of the following public
 * identifiers:
 * <ul>
 * <li><code>-//Primix Solutions//Tapestry Script 1.0//EN</code></li>
 * <li><code>-//Howard Ship//Tapestry Script 1.1//EN</code></li>
 * <li><code>-//Howard Lewis Ship//Tapestry Script 1.2//EN</code></li>
 * </ul>
 * <p>
 * The version 1.1, is largely backwards compatible to the old script, but adds
 * a number of new features (if, if-not, foreach and the use of property paths
 * with insert).
 * <p>
 * Version 1.2 removes the &lt;insert&gt; element, using an Ant-like syntax (
 * <code>${<i>expression</i>}</code>). It also replaces the attribute name
 * <code>property-path</code> with <code>expression</code> (because OGNL is
 * used).
 * <p>
 * A Tapestry Script is used, in association with the
 * {@link org.apache.tapestry.html.Body}and/or
 * {@link org.apache.tapestry.html.Script}components, to generate JavaScript
 * for use with a Tapestry component. Two seperate pieces of JavaScript can be
 * generated. The body section (associated with the <code>body</code> element
 * of the XML document) is typically used to define JavaScript functions (most
 * often, event handlers). The initialization section (associated with the
 * <code>initialization</code> element of the XML document) is used to add
 * JavaScript that will be evaluated when the page finishes loading (i.e., from
 * the HTML &lt;body&gt; element's onLoad event handler).
 *
 * @author Howard Lewis Ship
 */

public class ScriptParser
{
    public static final String SCRIPT_DTD_1_0_PUBLIC_ID = "-//Primix Solutions//Tapestry Script 1.0//EN";

    public static final String SCRIPT_DTD_1_1_PUBLIC_ID = "-//Howard Ship//Tapestry Script 1.1//EN";

    public static final String SCRIPT_DTD_1_2_PUBLIC_ID = "-//Howard Lewis Ship//Tapestry Script 1.2//EN";

    /** @since 3.0 */
    public static final String SCRIPT_DTD_3_0_PUBLIC_ID = "-//Apache Software Foundation//Tapestry Script Specification 3.0//EN";

    /** @since 4.1 */
    public static final String SCRIPT_DTD_4_0_PUBLIC_ID = "-//Apache Software Foundation//Tapestry Script Specification 4.0//EN";

    private RuleDirectedParser _parser;

    public ScriptParser(ClassResolver resolver, ExpressionEvaluator evaluator, ValueConverter valueConverter)
    {
        _parser = new RuleDirectedParser();

        _parser.registerEntity(SCRIPT_DTD_1_0_PUBLIC_ID,
                               "/org/apache/tapestry/script/Script_1_0.dtd");
        _parser.registerEntity(SCRIPT_DTD_1_1_PUBLIC_ID,
                               "/org/apache/tapestry/script/Script_1_1.dtd");
        _parser.registerEntity(SCRIPT_DTD_1_2_PUBLIC_ID,
                               "/org/apache/tapestry/script/Script_1_2.dtd");
        _parser.registerEntity(SCRIPT_DTD_3_0_PUBLIC_ID,
                               "/org/apache/tapestry/script/Script_3_0.dtd");
        _parser.registerEntity(SCRIPT_DTD_4_0_PUBLIC_ID,
                               "/org/apache/tapestry/script/Script_4_0.dtd");

        _parser.addRule("script", new ScriptRule(evaluator, valueConverter));
        _parser.addRule("let", new LetRule());
        _parser.addRule("set", new SetRule());
        _parser.addRule("include-script", new IncludeScriptRule());
        _parser.addRule("input-symbol", new InputSymbolRule(resolver));
        _parser.addRule("body", new BodyRule());
        _parser.addRule("initialization", new InitRule());
        _parser.addRule("if", new IfRule(true));
        _parser.addRule("if-not", new IfRule(false));
        _parser.addRule("foreach", new ForeachRule());
        _parser.addRule("unique", new UniqueRule());

        // This will go away when the 1.1 and earler DTDs are retired.
        _parser.addRule("insert", new InsertRule());

    }

    /**
     * Parses the given input stream to produce a parsed script, ready to
     * execute.
     */

    public IScript parse(Resource resourceLocation)
    {
        return (IScript) _parser.parse(resourceLocation);
    }

}