*

 * 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.tomcat.util.digester;

import java.util.List;

/**

 * <p><code>AbstractRuleImpl</code> provides basic services for <code>Rules</code> implementations.

 * Extending this class should make it easier to create a <code>Rules</code> implementation.</p>

 * 

 * <p><code>AbstractRuleImpl</code> manages the <code>Digester</code> 

 * and <code>namespaceUri</code> properties.

 * If the subclass overrides {@link #registerRule} (rather than {@link #add}),

 * then the <code>Digester</code> and <code>namespaceURI</code> of the <code>Rule</code>

 * will be set correctly before it is passed to <code>registerRule</code>.

 * The subclass can then perform whatever it needs to do to register the rule.</p>

 *

 * @since 1.5

 */

abstract public class AbstractRulesImpl implements Rules {

    // ------------------------------------------------------------- Fields

    /** Digester using this <code>Rules</code> implementation */

    private Digester digester;

    /** Namespace uri to assoicate with subsequent <code>Rule</code>'s */

    private String namespaceURI;

    // ------------------------------------------------------------- Properties

    /**

     * Return the Digester instance with which this Rules instance is

     * associated.

     */

    public Digester getDigester() {

        return digester;

    }

    /**

     * Set the Digester instance with which this Rules instance is associated.

     *

     * @param digester The newly associated Digester instance

     */

    public void setDigester(Digester digester) {

        this.digester = digester;

    }

    /**

     * Return the namespace URI that will be applied to all subsequently

     * added <code>Rule</code> objects.

     */

    public String getNamespaceURI() {

        return namespaceURI;

    }

    /**

     * Set the namespace URI that will be applied to all subsequently

     * added <code>Rule</code> objects.

     *

     * @param namespaceURI Namespace URI that must match on all

     *  subsequently added rules, or <code>null</code> for matching

     *  regardless of the current namespace URI

     */

    public void setNamespaceURI(String namespaceURI) {

        this.namespaceURI = namespaceURI;

    }

    // --------------------------------------------------------- Public Methods

    /**

     * Registers a new Rule instance matching the specified pattern.

     * This implementation sets the <code>Digester</code> and the

     * <code>namespaceURI</code> on the <code>Rule</code> before calling {@link #registerRule}.

     *

     * @param pattern Nesting pattern to be matched for this Rule

     * @param rule Rule instance to be registered

     */

    public void add(String pattern, Rule rule) {

        // set up rule

        if (this.digester != null) {

            rule.setDigester(this.digester);

        }

        if (this.namespaceURI != null) {

            rule.setNamespaceURI(this.namespaceURI);

        }

        registerRule(pattern, rule);

    }

    /** 

     * Register rule at given pattern.

     * The the Digester and namespaceURI properties of the given <code>Rule</code>

     * can be assumed to have been set properly before this method is called.

     *

     * @param pattern Nesting pattern to be matched for this Rule

     * @param rule Rule instance to be registered

     */ 

    abstract protected void registerRule(String pattern, Rule rule);

    /**

     * Clear all existing Rule instance registrations.

     */

    abstract public void clear();

    /**

     * Return a List of all registered Rule instances that match the specified

     * nesting pattern, or a zero-length List if there are no matches.  If more

     * than one Rule instance matches, they <strong>must</strong> be returned

     * in the order originally registered through the <code>add()</code>

     * method.

     *

     * @param pattern Nesting pattern to be matched

     *

     * @deprecated Call match(namespaceURI,pattern) instead.

     */

    public List match(String pattern) {

        return match(namespaceURI, pattern);

    }

    /**

     * Return a List of all registered Rule instances that match the specified

     * nesting pattern, or a zero-length List if there are no matches.  If more

     * than one Rule instance matches, they <strong>must</strong> be returned

     * in the order originally registered through the <code>add()</code>

     * method.

     *

     * @param namespaceURI Namespace URI for which to select matching rules,

     *  or <code>null</code> to match regardless of namespace URI

     * @param pattern Nesting pattern to be matched

     */

    abstract public List match(String namespaceURI, String pattern);

    /**

     * Return a List of all registered Rule instances, or a zero-length List

     * if there are no registered Rule instances.  If more than one Rule

     * instance has been registered, they <strong>must</strong> be returned

     * in the order originally registered through the <code>add()</code>

     * method.

     */

    abstract public List rules();

}