001    // Copyright 2004, 2005 The Apache Software Foundation
002    //
003    // Licensed under the Apache License, Version 2.0 (the "License");
004    // you may not use this file except in compliance with the License.
005    // You may obtain a copy of the License at
006    //
007    //     http://www.apache.org/licenses/LICENSE-2.0
008    //
009    // Unless required by applicable law or agreed to in writing, software
010    // distributed under the License is distributed on an "AS IS" BASIS,
011    // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
012    // See the License for the specific language governing permissions and
013    // limitations under the License.
014    
015    package org.apache.tapestry.contrib.valid;
016    
017    import org.apache.tapestry.valid.IValidator;
018    import org.apache.tapestry.valid.NumberValidator;
019    import org.apache.tapestry.valid.ValidField;
020    
021    /**
022     * Backwards compatible version of the 1.0.7 NumericField component. <table
023     * border=1>
024     * <tr>
025     * <td>Parameter</td>
026     * <td>Type</td>
027     * <td>Read / Write</td>
028     * <td>Required</td>
029     * <td>Default</td>
030     * <td>Description</td>
031     * </tr>
032     * <tr>
033     * <td>value</td>
034     * <td>{@link Number}</td>
035     * <td>R / W</td>
036     * <td>yes</td>
037     * <td>&nbsp;</td>
038     * <td>The value to be updated.
039     * <p>
040     * When the form is submitted, this parameter is only updated if the value is
041     * valid.
042     * <p>
043     * When rendering, a null value will render as the empty string. A value of zero
044     * will render normally.
045     * <p>
046     * When the form is submitted, the type of the binding is used to determine what
047     * kind of object to convert the string to.</td>
048     * </tr>
049     * <tr>
050     * <td>minimum</td>
051     * <td>{@link Number}</td>
052     * <td>R</td>
053     * <td>no</td>
054     * <td>&nbsp;</td>
055     * <td>The minimum value accepted for the field.</td>
056     * </tr>
057     * <tr>
058     * <td>maximum</td>
059     * <td>{@link Number}</td>
060     * <td>R</td>
061     * <td>no</td>
062     * <td>&nbsp;</td>
063     * <td>The maximum value accepted for the field.</td>
064     * </tr>
065     * <tr>
066     * <td>required</td>
067     * <td>boolean</td>
068     * <td>R</td>
069     * <td>no</td>
070     * <td>false</td>
071     * <td>If true, then a non-null value must be provided. If the field is not
072     * required, and a null (all whitespace) value is supplied in the field, then
073     * the value parameter is <em>not</em> updated.</td>
074     * </tr>
075     * <tr>
076     * <td>displayName</td>
077     * <td>String</td>
078     * <td>R</td>
079     * <td>yes</td>
080     * <td>&nbsp;</td>
081     * <td>A textual name for the field that is used when formulating error
082     * messages.</td>
083     * </tr>
084     * <tr>
085     * <td>type</td>
086     * <td>String</td>
087     * <td>R</td>
088     * <td>yes</td>
089     * <td>&nbsp;</td>
090     * <td>The class name used to convert the value entered. See
091     * {@link NumberValidator#setValueType(String)}</td>
092     * </tr>
093     * </table>
094     * <p>
095     * May not contain a body. May have informal parameters.
096     * 
097     * @author Howard Lewis Ship
098     * @since 1.0.8
099     * @see ValidField
100     */
101    
102    public abstract class NumericField extends ValidField
103    {
104    
105        public abstract Number getMinimum();
106    
107        public abstract Number getMaximum();
108    
109        public abstract boolean isRequired();
110    
111        public abstract String getType();
112    
113        /**
114         * Overrides {@link ValidField#getValidator()}to construct a validator on
115         * the fly.
116         */
117    
118        public IValidator getValidator()
119        {
120            NumberValidator validator = new NumberValidator();
121    
122            if (isParameterBound("minimum")) validator.setMinimum(getMinimum());
123    
124            if (isParameterBound("maximum")) validator.setMaximum(getMaximum());
125    
126            if (isParameterBound("required")) validator.setRequired(isRequired());
127    
128            if (isParameterBound("type")) validator.setValueType(getType());
129    
130            return validator;
131        }
132    }