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
015package org.apache.tapestry.contrib.valid;
016
017import org.apache.tapestry.valid.IValidator;
018import org.apache.tapestry.valid.NumberValidator;
019import org.apache.tapestry.valid.ValidField;
020
021/**
022 * Backwards compatible version of the 1.0.7 NumericField component. <table border=1>
023 * <tr>
024 * <td>Parameter</td>
025 * <td>Type</td>
026 * <td>Read / Write</td>
027 * <td>Required</td>
028 * <td>Default</td>
029 * <td>Description</td>
030 * </tr>
031 * <tr>
032 * <td>value</td>
033 * <td>{@link Number}</td>
034 * <td>R / W</td>
035 * <td>yes</td>
036 * <td>&nbsp;</td>
037 * <td>The value to be updated.
038 * <p>
039 * When the form is submitted, this parameter is only updated if the value is valid.
040 * <p>
041 * When rendering, a null value will render as the empty string. A value of zero will render
042 * normally.
043 * <p>
044 * When the form is submitted, the type of the binding is used to determine what kind of object to
045 * convert the string to.</td>
046 * </tr>
047 * <tr>
048 * <td>minimum</td>
049 * <td>{@link Number}</td>
050 * <td>R</td>
051 * <td>no</td>
052 * <td>&nbsp;</td>
053 * <td>The minimum value accepted for the field.</td>
054 * </tr>
055 * <tr>
056 * <td>maximum</td>
057 * <td>{@link Number}</td>
058 * <td>R</td>
059 * <td>no</td>
060 * <td>&nbsp;</td>
061 * <td>The maximum value accepted for the field.</td>
062 * </tr>
063 * <tr>
064 * <td>required</td>
065 * <td>boolean</td>
066 * <td>R</td>
067 * <td>no</td>
068 * <td>false</td>
069 * <td>If true, then a non-null value must be provided. If the field is not required, and a null
070 * (all whitespace) value is supplied in the field, then the value parameter is <em>not</em>
071 * updated.</td>
072 * </tr>
073 * <tr>
074 * <td>displayName</td>
075 * <td>String</td>
076 * <td>R</td>
077 * <td>yes</td>
078 * <td>&nbsp;</td>
079 * <td>A textual name for the field that is used when formulating error messages.</td>
080 * </tr>
081 * <tr>
082 * <td>type</td>
083 * <td>String</td>
084 * <td>R</td>
085 * <td>yes</td>
086 * <td>&nbsp;</td>
087 * <td>The class name used to convert the value entered. See
088 * {@link NumberValidator#setValueType(String)}</td>
089 * </tr>
090 * </table>
091 * <p>
092 * May not contain a body. May have informal parameters.
093 * 
094 * @author Howard Lewis Ship
095 * @since 1.0.8
096 * @see ValidField
097 */
098
099public abstract class NumericField extends ValidField
100{
101    public abstract Number getMinimum();
102
103    public abstract Number getMaximum();
104
105    public abstract boolean isRequired();
106
107    public abstract String getType();
108
109    /**
110     * Overrides {@link ValidField#getValidator()}to construct a validator on the fly.
111     */
112
113    public IValidator getValidator()
114    {
115        NumberValidator validator = new NumberValidator();
116
117        if (isParameterBound("minimum"))
118            validator.setMinimum(getMinimum());
119
120        if (isParameterBound("maximum"))
121            validator.setMaximum(getMaximum());
122
123        if (isParameterBound("required"))
124            validator.setRequired(isRequired());
125
126        if (isParameterBound("type"))
127            validator.setValueType(getType());
128
129        return validator;
130    }
131}