src/java/org/apache/commons/digester/CallParamRule.java

/*
 * $Header: /home/jerenkrantz/tmp/commons/commons-convert/cvs/home/cvs/jakarta-commons//digester/src/java/org/apache/commons/digester/CallParamRule.java,v 1.7 2002/03/23 17:45:57 rdonkin Exp $
 * $Revision: 1.7 $
 * $Date: 2002/03/23 17:45:57 $
 *
 * ====================================================================
 *
 * The Apache Software License, Version 1.1
 *
 * Copyright (c) 1999-2002 The Apache Software Foundation.  All rights
 * reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 *
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in
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 *    distribution.
 *
 * 3. The end-user documentation included with the redistribution, if
 *    any, must include the following acknowlegement:
 *       "This product includes software developed by the
 *        Apache Software Foundation (http://www.apache.org/)."
 *    Alternately, this acknowlegement may appear in the software itself,
 *    if and wherever such third-party acknowlegements normally appear.
 *
 * 4. The names "The Jakarta Project", "Commons", and "Apache Software
 *    Foundation" must not be used to endorse or promote products derived
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 *    permission, please contact apache@apache.org.
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 * 5. Products derived from this software may not be called "Apache"
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 */


package org.apache.commons.digester;


import java.lang.reflect.Method;

import org.xml.sax.Attributes;


/**
 * Rule implementation that saves a parameter from either an attribute of
 * this element, or from the element body, to be used in a call generated
 * by a surrounding CallMethodRule rule.
 *
 * @author Craig McClanahan
 * @version $Revision: 1.7 $ $Date: 2002/03/23 17:45:57 $
 */

public class CallParamRule extends Rule {


    // ----------------------------------------------------------- Constructors


    /**
     * Construct a "call parameter" rule that will save the body text of this
     * element as the parameter value.
     *
     * @param digester The associated Digester
     * @param paramIndex The zero-relative parameter number
     *
     * @deprecated The digester instance is now set in the {@link Digester#addRule} method. 
     * Use {@link #CallParamRule(int paramIndex)} instead.
     */
    public CallParamRule(Digester digester, int paramIndex) {

        this(paramIndex);

    }


    /**
     * Construct a "call parameter" rule that will save the value of the
     * specified attribute as the parameter value.
     *
     * @param digester The associated Digester
     * @param paramIndex The zero-relative parameter number
     * @param attributeName The name of the attribute to save
     *
     * @deprecated The digester instance is now set in the {@link Digester#addRule} method. 
     * Use {@link #CallParamRule(int paramIndex, String attributeName)} instead.
     */
    public CallParamRule(Digester digester, int paramIndex,
                         String attributeName) {

        this(paramIndex, attributeName);

    }

    /**
     * Construct a "call parameter" rule that will save the body text of this
     * element as the parameter value.
     *
     * @param paramIndex The zero-relative parameter number
     */
    public CallParamRule(int paramIndex) {

        this(paramIndex, null);

    }


    /**
     * Construct a "call parameter" rule that will save the value of the
     * specified attribute as the parameter value.
     *
     * @param paramIndex The zero-relative parameter number
     * @param attributeName The name of the attribute to save
     */
    public CallParamRule(int paramIndex,
                         String attributeName) {

        this.paramIndex = paramIndex;
        this.attributeName = attributeName;

    }


    // ----------------------------------------------------- Instance Variables


    /**
     * The attribute from which to save the parameter value
     */
    protected String attributeName = null;


    /**
     * The body text collected from this element.
     */
    protected String bodyText = null;


    /**
     * The zero-relative index of the parameter we are saving.
     */
    protected int paramIndex = 0;


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


    /**
     * Process the start of this element.
     *
     * @param attributes The attribute list for this element
     */
    public void begin(Attributes attributes) throws Exception {

        if (attributeName != null) {
            bodyText = attributes.getValue(attributeName);
        }

    }


    /**
     * Process the body text of this element.
     *
     * @param bodyText The body text of this element
     */
    public void body(String bodyText) throws Exception {

        if (attributeName == null) {
            this.bodyText = bodyText.trim();
        }

    }


    /**
     * Process the end of this element.
     */
    public void end() throws Exception {

        String parameters[] = (String[]) digester.peekParams();
        parameters[paramIndex] = bodyText;

    }


    /**
     * Clean up after parsing is complete.
     */
    public void finish() throws Exception {

        bodyText = null;

    }


    /**
     * Render a printable version of this Rule.
     */
    public String toString() {

        StringBuffer sb = new StringBuffer("CallParamRule[");
        sb.append("paramIndex=");
        sb.append(paramIndex);
        sb.append(", attributeName=");
        sb.append(attributeName);
        sb.append("]");
        return (sb.toString());

    }


}