HTMLSelectFieldRenderer.java

/**
 * HTMLSelectFieldRenderer - Subcomponent which can render a SelectField value to a DOM Element.
 *
 * Copyright (c) 2002
 *      Marty Phelan, All rights reserved.
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2.1 of the License, or (at your option) any later version.
 *
 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with this library; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 *
 */
package com.taursys.html.render;

import com.taursys.xml.render.SelectFieldRenderer;
import com.taursys.xml.event.RenderException;
import com.taursys.xml.SelectField;
import com.taursys.model.ModelException;
import com.taursys.model.*;
import com.taursys.xml.DocumentComponent;
import com.taursys.dom.DocumentAdapter;
import org.w3c.dom.*;
import org.w3c.dom.html.*;
import java.util.Collection;
import java.util.Iterator;

/**
 * Subcomponent which can render a value from a SelectField to a DOM Element as a TextNode.
 */
public class HTMLSelectFieldRenderer extends SelectFieldRenderer {

  /**
   * Constructs a new SelectFieldRender.
   * @deprecated - use constructor that takes a SelectField as parameter
   */
  public HTMLSelectFieldRenderer() {
    super(null);
  }

  /**
   * Constructs a new SelectFieldRender.
   */
  public HTMLSelectFieldRenderer(SelectField c) {
    super(c);
  }

  /**
   * Renders the given SelectField to a Text Node of Element in a Document.
   * This component accesses the given textField's parent to obtain the
   * DocumentAdapter.  It also accesses the given field's id and model.
   * It uses the DocumentAdapter's setElementText to render the model's text
   * value to the Element indicated by the id.
   * @throws RenderException if any problem occurs during rendering
   * @deprecated - use constructor that takes a SelectField as parameter and
   * render that takes no parameters.
   */
  public void render(SelectField field) throws RenderException {
    try {
      DocumentAdapter da = field.getParent().getDocumentAdapter();
      Element element = (Element)da.getElementById(field.getId());
      SelectModel model = (SelectModel)field.getModel();
      // Remove existing options (if any)
      while(element.hasChildNodes())
        element.removeChild(element.getFirstChild());
      // Get List of options and add to SELECT element
      Collection c = model.getDisplayOptionList();
      Iterator iter = c.iterator();
      while (iter.hasNext()) {
        SelectModelOption option = (SelectModelOption)iter.next();
        addOPTION(element, option.getOptionText(), option.isSelected());
      }
    } catch (ModelException ex) {
      throw new RenderException(RenderException.REASON_MODEL_EXCEPTION, ex);
    }
  }

  /**
   * Renders the given SelectField to a Text Node of Element in a Document.
   * This component accesses the given textField's parent to obtain the
   * DocumentAdapter.  It also accesses the given field's id and model.
   * It uses the DocumentAdapter's setElementText to render the model's text
   * value to the Element indicated by the id.
   * @throws RenderException if any problem occurs during rendering
   */
  public void render() throws RenderException {
    init();
    if (getComponent().isVisible()) {
      restoreSelf();
      try {
        DocumentAdapter da = getComponent().getParent().getDocumentAdapter();
        Element element = (Element)da.getElementById(((DocumentComponent)getComponent()).getId());
        if (element != null) {
          SelectModel model = (SelectModel)((SelectField)getComponent()).getModel();
          // Remove existing options (if any)
          while(element.hasChildNodes())
            element.removeChild(element.getFirstChild());
          // Get List of options and add to SELECT element
          Collection c = model.getDisplayOptionList();
          Iterator iter = c.iterator();
          while (iter.hasNext()) {
            SelectModelOption option = (SelectModelOption)iter.next();
            addOPTION(element, option.getOptionText(), option.isSelected());
          }
        }
      } catch (ModelException ex) {
        throw new RenderException(RenderException.REASON_MODEL_EXCEPTION, ex);
      }
    } else {
      removeSelf();
    }
  }

  /**
   * Adds an OPTION to given element with given value as TextNode and "selected" attribute set if selected.
   */
  private void addOPTION(Element element, String value, boolean selected) {
    // Create a new option element
    Element option = element.getOwnerDocument().createElement("OPTION");
    // Store the display value in a text node
    option.appendChild(element.getOwnerDocument().createTextNode(value));
    // Set the selected attribute if this option = value
    if (selected)
      option.setAttribute("Selected","Selected");
    // Add this OPTION the the SELECT element
    element.appendChild(option);
  }
}