/**
 * License Agreement.
 *
 * Rich Faces - Natural Ajax for Java Server Faces (JSF)
 *
 * Copyright (C) 2007 Exadel, Inc.
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License version 2.1 as published by the Free Software Foundation.
 *
 * 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., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301  USA
 */

package org.ajax4jsf.component;

import javax.el.ValueExpression;
import javax.faces.FacesException;
import javax.faces.component.UIComponent;
import javax.faces.context.FacesContext;

import org.ajax4jsf.Messages;
import org.ajax4jsf.renderkit.AjaxRendererUtils;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;

/**
 * Component for append ajax functions to any control component. Append action
 * functionality to non-action control, setup javascript events for parent
 * component,
 * 
 * @author shura (latest modification by $Author: alexsmirnov $)
 * @version $Revision: 1.1.2.3 $ $Date: 2007/02/12 17:46:52 $
 * 
 */
public abstract class UIAjaxSupport extends AjaxActionComponent implements
		AjaxSupport {

	// ~ Static fields/initializers
	// ---------------------------------------------

	public static final String COMPONENT_TYPE = "org.ajax4jsf.Support";
	public static final String COMPONENT_FAMILY = "org.ajax4jsf.AjaxSupport";
	public static final String DEFAULT_RENDERER_TYPE = "org.ajax4jsf.components.AjaxSupportRenderer";
	public static final String AJAX_SUPPORT_SET = "com.exadel.components.ajax.support.";
	private static final Log log = LogFactory.getLog(UIAjaxSupport.class);

	@Override
	public void setValueExpression(String name, ValueExpression binding) {
		// var - not allowed name. must be literal.
		if ("var".equals(name)) {
			throw new FacesException(Messages.getMessage(
					Messages.VAR_MUST_BE_LITERAL,
					getClientId(getFacesContext())));
		}
		if ("event".equals(name)) {
			throw new FacesException(Messages.getMessage(
					Messages.EVENT_MUST_BE_LITERAL,
					getClientId(getFacesContext())));
		}
		super.setValueExpression(name, binding);
	}
	
	/**
	 * Create Special <code>ValueBinding</code> for build JavaScrept event
	 * code in parent component from this.
	 * 
	 * @return <code>EventValueBinding</code> based on properties of current
	 *         component
	 */
	private ValueExpression getEventValueBinding() {
		if (log.isDebugEnabled()) {
			log.debug(Messages.getMessage(Messages.CREATE_JAVASCRIPT_EVENT,
					getId()));
		}
		return new EventValueExpression(this);
	}

	/**
	 * @return JavaScript eventString. Rebuild on every call, since can be in
	 *         loop ( as in dataTable ) with different parameters.
	 */
	public String getEventString() {
		StringBuffer buildOnEvent = new StringBuffer();
		String onsubmit = getOnsubmit();
		// Insert script to call before submit ajax request.
		if (null != onsubmit) {
			buildOnEvent.append(onsubmit).append(";");
		}
		buildOnEvent.append(AjaxRendererUtils.buildOnEvent(this,
				getFacesContext(), getEvent()));
		String script = buildOnEvent.toString();
		return script;
	}

	/*
	 * (non-Javadoc)
	 * 
	 * @see javax.faces.component.UIComponentBase#decode(javax.faces.context.FacesContext)
	 */
	public void decode(FacesContext context) {
		// Due to JSF RI 1.1 bug, clear cached clientId
		setId(getId());
		super.decode(context);
	}

	/**
	 * After nornal setting <code>parent</code> property in case of created
	 * component set Ajax properties for parent.
	 * 
	 * @see javax.faces.component.UIComponentBase#setParent(javax.faces.component.UIComponent)
	 */
	public void setParent(UIComponent parent) {
		super.setParent(parent);
		if (null != parent && parent.getFamily() != null) {
			if (log.isDebugEnabled()) {
				log.debug(Messages.getMessage(Messages.CALLED_SET_PARENT,
						parent.getClass().getName()));
			}
			// TODO If this comopnent configured, set properties for parent
			// component.
			// NEW created component have parent, restored view - null in My
			// faces.
			// and SUN RI not call at restore saved view.
			// In other case - set in restoreState method.
			// if (parent.getParent() != null)
			{
				if (log.isDebugEnabled()) {
					log.debug(Messages
							.getMessage(Messages.DETECT_NEW_COMPONENT));
				}
				setParentProperties(parent);

			}
		}
	}

	public void setParentProperties(UIComponent parent) {
		ValueExpression valueBinding;
		if (null != getEvent()) {
			if (log.isDebugEnabled()) {
				log.debug(Messages.getMessage(
						Messages.SET_VALUE_BINDING_FOR_EVENT, getEvent()));
			}
			// for non action/data components, or for non-default events - build
			// listener for this instance.
			valueBinding = getEventValueBinding();
			parent.setValueExpression(getEvent(), valueBinding);

		}
	}

	protected UIComponent getSingleComponent() {
		return getParent();
	}

}
