org.apache.myfaces.trinidad.webapp.TrinidadValidatorELTag Maven / Gradle / Ivy

/*
 * 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.myfaces.trinidad.webapp;

import javax.faces.component.EditableValueHolder;
import javax.faces.component.UIComponent;
import javax.faces.validator.Validator;
import javax.faces.webapp.UIComponentClassicTagBase;
import javax.faces.webapp.UIComponentELTag;
import javax.servlet.jsp.JspException;
import javax.servlet.jsp.tagext.Tag;

/**
 * This is the Trinidad version of the JSF ValidatorELTag class.
 * The main difference is that this class is NOT inheriting from 
 * the standard TagSupport and therefore does not 
 * implement Serializable interface.
 * 
 * @author Apache MyFaces team
 */
public abstract class TrinidadValidatorELTag extends TrinidadTagSupport
{
    @Override
    public int doStartTag() throws JspException
    {
        UIComponentClassicTagBase componentTag = UIComponentELTag.getParentUIComponentClassicTagBase(pageContext);

        if (componentTag == null)
        {
            throw new JspException("no parent UIComponentTag found");
        }

        if (!componentTag.getCreated())
        {
            return Tag.SKIP_BODY;
        }

        Validator validator = createValidator();

        UIComponent component = componentTag.getComponentInstance();
        if (component == null)
        {
            throw new JspException("parent UIComponentTag has no UIComponent");
        }

        if (!(component instanceof EditableValueHolder))
        {
            throw new JspException("UIComponent is no EditableValueHolder");
        }
        ((EditableValueHolder)component).addValidator(validator);

        return Tag.SKIP_BODY;
    }

    protected abstract Validator createValidator() throws JspException;

}