org.polymap.rhei.field.NotEmptyValidator.java Source code

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Here is the source code for org.polymap.rhei.field.NotEmptyValidator.java

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/*
 * polymap.org 
 * Copyright (C) 2013-2014 Polymap GmbH. All rights reserved.
 * 
 * This 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 software 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.
 */
package org.polymap.rhei.field;

import org.apache.commons.lang3.StringUtils;

/**
 * Checks if the value is null or empty if instance of String.
 * 
 * @author <a href="http://www.polymap.de">Steffen Stundzig</a>
 * @author <a href="http://www.polymap.de">Falko Brutigam</a>
 */
public class NotEmptyValidator<F, M> implements IFormFieldValidator<F, M> {

    public String validate(F fieldValue) {
        if (fieldValue == null) {
            return "Dieses Feld darf nicht leer sein";
        }
        // used for
        else if (fieldValue instanceof String) {
            String str = (String) fieldValue;
            if (str.length() == 0 || StringUtils.containsOnly(str, " \t\n\r")) {
                return "Dieses Feld darf nicht leer sein";
            }
        }
        return null;
    }

    @Override
    public M transform2Model(F fieldValue) throws Exception {
        return (M) fieldValue;
    }

    @Override
    public F transform2Field(M modelValue) throws Exception {
        return (F) modelValue;
    }

}