/*
 * 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.cocoon.forms.binding;

import org.apache.cocoon.forms.formmodel.Widget;
import org.apache.cocoon.forms.formmodel.tree.Tree;
import org.apache.cocoon.forms.formmodel.tree.TreeModel;
import org.apache.commons.jxpath.JXPathContext;

public class TreeModelJXPath extends JXPathBindingBase {

    /**
     * The xpath expression to the objectModel property
     */
    private final String xpath;

    /**
     * The id of the CForms form-widget
     */
    private final String fieldId;
	
    /**
     * Constructs FieldJXPathBinding.
     */
    public TreeModelJXPath(JXPathBindingBuilderBase.CommonAttributes commonAtts,
                              String widgetId,
                              String xpath) {
        super(commonAtts);
        this.fieldId = widgetId;
        this.xpath = xpath;
    }

    public String getId() { return fieldId; }

    /**
     * Actively performs the binding from the ObjectModel wrapped in a jxpath
     * context to the CForms-form-widget specified in this object.
     */
    public void doLoad(Widget frmModel, JXPathContext jxpc) throws BindingException {
        Widget widget = selectWidget(frmModel, this.fieldId);
        if (widget == null) {
            throw new BindingException("The widget with the ID [" + this.fieldId
                    + "] referenced in the binding does not exist in the form definition.");
        }
        if (!(widget instanceof Tree)) throw new BindingException("Widget " + this.fieldId + " is not a Tree!");

        Object value = jxpc.getValue(this.xpath);
        if (value != null) {
            if (!(value instanceof TreeModel)) throw new BindingException("Value found in " + this.xpath + " is not a TreeModel, instead it is a " + value.getClass().getName());
            ((Tree)widget).setModel((TreeModel)value);
        }
    }

	public void doSave(Widget frmModel, JXPathContext jxpc)
    throws BindingException {
		// Does nothing
	}

}