TargetValueValidator.java

/*******************************************************************************
 * Copyright 2006 - 2012 Vienna University of Technology,
 * Department of Software Technology and Interactive Systems, IFS
 * 
 * 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 eu.scape_project.planning.validators;

import javax.faces.application.FacesMessage;
import javax.faces.component.UIComponent;
import javax.faces.context.FacesContext;
import javax.faces.validator.Validator;
import javax.faces.validator.ValidatorException;

/**
 * Implements a JSF validator that checks the respective value for being not null and
 * between 0.0 and 5.0. This validator serves a special purpose namely the validation of
 * target value input in the workflow step Transform Measured Values.
 *
 * @author Hannes Kulovits
 */
public class TargetValueValidator implements Validator {

    public TargetValueValidator() {
    }

    /**
     * Overrides {@link javax.faces.validator.Validator#validate(FacesContext, UIComponent, Object)}
     */
    public void validate(FacesContext context, UIComponent component, Object value)
        throws ValidatorException {

        if (value == null) {
            throw new ValidatorException(new FacesMessage(FacesMessage.SEVERITY_ERROR, "Validation error.", "Target value must be between 0.0 and 5.0."));
        }
        // The converter has taken care of conversion... hopefully.
        // Otherwise we will notice immediately :)
        Double doubleValue = (Double)value;

        if (! (doubleValue >= 0.0 && doubleValue <= 5.0)) {
            throw new ValidatorException(new FacesMessage(FacesMessage.SEVERITY_ERROR, "Validation error.", "Target value must be between 0.0 and 5.0."));
        }
    }
}