taglibs-rdc/src/main/java/org/apache/taglibs/rdc/Number.java

/*
 * 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.taglibs.rdc;

import org.apache.taglibs.rdc.core.BaseModel;

/**
 * Datamodel for the number RDC. The number RDC will be associated with 
 * the number input and the maximum and minimum value within which the 
 * input's value must lie.
 *
 * @author Sandeep Jindal
 * @author Rahul Akolkar
 */

public class Number extends BaseModel {

    // The default/initial value of number
    // initial is of type String and not Double because 
    // Double.toString returns scientific notation for 
    // numbers less that 10 pow -3 and greater than 10 pow 7.
    // The value returned by the grammar is fixed-number representation
    // and initial must conform to that.

    // Maximum allowed value of the input; null value indicates 
    // no constraint on maximum value
    private Double minValue;

    // Minimum allowed value of the input; null value indicates 
    // no constraint on minimum value 
    private Double maxValue;

    // Error codes, defined in configuration file
    /**A constant for Error Code stating the number entered is 
     * longer than allowed */
    public static final int ERR_NEED_SHORTER_NUMBER = 1;

    /**A constant for Error Code stating the number entered is 
     * shorter than allowed */
    public static final int ERR_NEED_LONGER_NUMBER = 2;

    /**
     * Sets default values for all data members
     */
    public Number() {
        super();
        this.minValue = null;
        this.maxValue = null;
    }

    /**
     * Gets the maximum allowed value of number
     * 
     * @return The maximum allowed value of number
     */
    public String getMaxValue() {
        return maxValue.toString();
    }

    /**
     * Sets the maximum allowed value of input
     * 
     * @param maxValue the maximum allowed value of input
     */
    public void setMaxValue(String maxValue) {
        if (maxValue != null) {
            this.maxValue = (Double)canonicalize(maxValue, true);
        }
    }

    /**
     * Gets the minimum allowed value of number
     * @return The minimum allowed value of number
     */

    public String getMinValue() {
        return minValue.toString();
    }

    /**
     * Sets the minimum allowed value 
     * 
     * @param minValue the minimum allowed value of input
     */
    public void setMinValue(String minValue) {
        if (minValue != null) {
            this.minValue = (Double)canonicalize(minValue, true);
        }
    }

    /**
     * Custom canonicalization
     */
    protected Object canonicalize(Object newValue, boolean isAttribute) {
        Double dabal = null;
        try {
            dabal = new Double((String) newValue);
        } catch (NumberFormatException e) {
            if (isAttribute) {
                throw new IllegalArgumentException("Cannot canonicalize " +
                "value " + newValue + " for number tag with ID " + getId());
            }
        }
        return dabal;
    }

    /**
     * Validates the input against the given constraints
     * 
     * @return TRUE if valid, FALSE otherwise
     */
    protected Boolean validate(Object newValue, boolean setErrorCode) {

        if (maxValue != null && maxValue.compareTo(newValue) < 0) {
            if (setErrorCode) setErrorCode(ERR_NEED_SHORTER_NUMBER);
            return Boolean.FALSE;
        }
        if (minValue != null && minValue.compareTo(newValue) > 0) {
            if (setErrorCode) setErrorCode(ERR_NEED_LONGER_NUMBER);
            return Boolean.FALSE;
        }
        return Boolean.TRUE;
    }

}