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 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> </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> </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> </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> </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> </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    
099    public 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    }