/*
 * $Id: ELIterateTag.java 54933 2004-10-16 17:04:52Z germuska $ 
 *
 * Copyright 1999-2004 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.strutsel.taglib.logic;

import org.apache.struts.taglib.logic.IterateTag;
import javax.servlet.jsp.JspException;
import org.apache.strutsel.taglib.utils.EvalHelper;

/**
 * Custom tag that iterates the elements of a collection, which can be
 * either an attribute or the property of an attribute.  The collection
 * can be any of the following:  an array of objects, an Enumeration,
 * an Iterator, a Collection (which includes Lists, Sets and Vectors),
 * or a Map (which includes Hashtables) whose elements will be iterated over.
 *<p>
 * This class is a subclass of the class
 * <code>org.apache.struts.taglib.logic.IterateTag</code> which provides most of
 * the described functionality.  This subclass allows all attribute values to
 * be specified as expressions utilizing the JavaServer Pages Standard Library
 * expression language.
 *
 * @version $Rev: 54933 $
 */
public class ELIterateTag extends IterateTag {

    /**
     * Instance variable mapped to "collection" tag attribute.
     * (Mapping set in associated BeanInfo class.)
     */
    private String collectionExpr;
    /**
     * Instance variable mapped to "id" tag attribute.
     * (Mapping set in associated BeanInfo class.)
     */
    private String idExpr;
    /**
     * Instance variable mapped to "indexId" tag attribute.
     * (Mapping set in associated BeanInfo class.)
     */
    private String indexIdExpr;
    /**
     * Instance variable mapped to "length" tag attribute.
     * (Mapping set in associated BeanInfo class.)
     */
    private String lengthExpr;
    /**
     * Instance variable mapped to "name" tag attribute.
     * (Mapping set in associated BeanInfo class.)
     */
    private String nameExpr;
    /**
     * Instance variable mapped to "offset" tag attribute.
     * (Mapping set in associated BeanInfo class.)
     */
    private String offsetExpr;
    /**
     * Instance variable mapped to "property" tag attribute.
     * (Mapping set in associated BeanInfo class.)
     */
    private String propertyExpr;
    /**
     * Instance variable mapped to "scope" tag attribute.
     * (Mapping set in associated BeanInfo class.)
     */
    private String scopeExpr;
    /**
     * Instance variable mapped to "type" tag attribute.
     * (Mapping set in associated BeanInfo class.)
     */
    private String typeExpr;

    /**
     * Getter method for "collection" tag attribute.
     * (Mapping set in associated BeanInfo class.)
     */
    public String getCollectionExpr() { return (collectionExpr); }
    /**
     * Getter method for "id" tag attribute.
     * (Mapping set in associated BeanInfo class.)
     */
    public String getIdExpr() { return (idExpr); }
    /**
     * Getter method for "indexId" tag attribute.
     * (Mapping set in associated BeanInfo class.)
     */
    public String getIndexIdExpr() { return (indexIdExpr); }
    /**
     * Getter method for "length" tag attribute.
     * (Mapping set in associated BeanInfo class.)
     */
    public String getLengthExpr() { return (lengthExpr); }
    /**
     * Getter method for "name" tag attribute.
     * (Mapping set in associated BeanInfo class.)
     */
    public String getNameExpr() { return (nameExpr); }
    /**
     * Getter method for "offset" tag attribute.
     * (Mapping set in associated BeanInfo class.)
     */
    public String getOffsetExpr() { return (offsetExpr); }
    /**
     * Getter method for "property" tag attribute.
     * (Mapping set in associated BeanInfo class.)
     */
    public String getPropertyExpr() { return (propertyExpr); }
    /**
     * Getter method for "scope" tag attribute.
     * (Mapping set in associated BeanInfo class.)
     */
    public String getScopeExpr() { return (scopeExpr); }
    /**
     * Getter method for "type" tag attribute.
     * (Mapping set in associated BeanInfo class.)
     */
    public String getTypeExpr() { return (typeExpr); }

    /**
     * Setter method for "collection" tag attribute.
     * (Mapping set in associated BeanInfo class.)
     */
    public void setCollectionExpr(String collectionExpr) { this.collectionExpr = collectionExpr; }
    /**
     * Setter method for "id" tag attribute.
     * (Mapping set in associated BeanInfo class.)
     */
    public void setIdExpr(String idExpr) { this.idExpr = idExpr; }
    /**
     * Setter method for "indexId" tag attribute.
     * (Mapping set in associated BeanInfo class.)
     */
    public void setIndexIdExpr(String indexIdExpr) { this.indexIdExpr = indexIdExpr; }
    /**
     * Setter method for "length" tag attribute.
     * (Mapping set in associated BeanInfo class.)
     */
    public void setLengthExpr(String lengthExpr) { this.lengthExpr = lengthExpr; }
    /**
     * Setter method for "name" tag attribute.
     * (Mapping set in associated BeanInfo class.)
     */
    public void setNameExpr(String nameExpr) { this.nameExpr = nameExpr; }
    /**
     * Setter method for "offset" tag attribute.
     * (Mapping set in associated BeanInfo class.)
     */
    public void setOffsetExpr(String offsetExpr) { this.offsetExpr = offsetExpr; }
    /**
     * Setter method for "property" tag attribute.
     * (Mapping set in associated BeanInfo class.)
     */
    public void setPropertyExpr(String propertyExpr) { this.propertyExpr = propertyExpr; }
    /**
     * Setter method for "scope" tag attribute.
     * (Mapping set in associated BeanInfo class.)
     */
    public void setScopeExpr(String scopeExpr) { this.scopeExpr = scopeExpr; }
    /**
     * Setter method for "type" tag attribute.
     * (Mapping set in associated BeanInfo class.)
     */
    public void setTypeExpr(String typeExpr) { this.typeExpr = typeExpr; }

    /**
     * Releases state of custom tag so this instance can be reused.
     */
    public void release()
    {
        super.release();
        setCollectionExpr(null);
        setIdExpr(null);
        setIndexIdExpr(null);
        setLengthExpr(null);
        setNameExpr(null);
        setOffsetExpr(null);
        setPropertyExpr(null);
        setScopeExpr(null);
        setTypeExpr(null);
    }

    /**
     * Process the start tag.
     *
     * @exception JspException if a JSP exception has occurred
     */
    public int doStartTag() throws JspException {
        evaluateExpressions();
        return(super.doStartTag());
    }

    /**
     * Processes all attribute values which use the JSTL expression evaluation
     * engine to determine their values.
     *
     * @exception JspException if a JSP exception has occurred
     */
    private void evaluateExpressions() throws JspException {
        String string   = null;
        Object object   = null;

        if ((object = EvalHelper.eval("collection", getCollectionExpr(),
                                      this, pageContext)) != null)
            setCollection(object);

        if ((string = EvalHelper.evalString("id", getIdExpr(),
                                            this, pageContext)) != null)
            setId(string);

        if ((string = EvalHelper.evalString("indexId", getIndexIdExpr(),
                                            this, pageContext)) != null)
            setIndexId(string);

        if ((string = EvalHelper.evalString("length", getLengthExpr(),
                                            this, pageContext)) != null)
            setLength(string);

        if ((string = EvalHelper.evalString("name", getNameExpr(),
                                            this, pageContext)) != null)
            setName(string);

        if ((string = EvalHelper.evalString("offset", getOffsetExpr(),
                                            this, pageContext)) != null)
            setOffset(string);

        if ((string = EvalHelper.evalString("property", getPropertyExpr(),
                                            this, pageContext)) != null)
            setProperty(string);

        if ((string = EvalHelper.evalString("scope", getScopeExpr(),
                                            this, pageContext)) != null)
            setScope(string);

        if ((string = EvalHelper.evalString("type", getTypeExpr(),
                                            this, pageContext)) != null)
            setType(string);
    }
}