001    // Copyright 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.form.validator;
016    
017    import org.apache.tapestry.IMarkupWriter;
018    import org.apache.tapestry.IRequestCycle;
019    import org.apache.tapestry.TapestryUtils;
020    import org.apache.tapestry.form.FormComponentContributorContext;
021    import org.apache.tapestry.form.IFormComponent;
022    import org.apache.tapestry.form.ValidationMessages;
023    import org.apache.tapestry.valid.ValidationConstraint;
024    import org.apache.tapestry.valid.ValidationStrings;
025    import org.apache.tapestry.valid.ValidatorException;
026    
027    /**
028     * Validates that the value, a string, is of a minimum length.
029     * 
030     * @author Howard Lewis Ship
031     * @since 4.0
032     */
033    public class MinLength extends BaseValidator
034    {
035        private int _minLength;
036    
037        public MinLength()
038        {
039        }
040    
041        public MinLength(String initializer)
042        {
043            super(initializer);
044        }
045    
046        public void setMinLength(int minLength)
047        {
048            _minLength = minLength;
049        }
050    
051        public int getMinLength()
052        {
053            return _minLength;
054        }
055    
056        public void validate(IFormComponent field, ValidationMessages messages, Object object)
057                throws ValidatorException
058        {
059            String string = (String) object;
060    
061            if (string.length() < _minLength)
062                throw new ValidatorException(buildMessage(messages, field),
063                        ValidationConstraint.MINIMUM_WIDTH);
064        }
065    
066        protected String buildMessage(ValidationMessages messages, IFormComponent field)
067        {
068            return messages.formatValidationMessage(
069                    getMessage(),
070                    ValidationStrings.VALUE_TOO_SHORT,
071                    new Object[]
072                    { new Integer(_minLength), field.getDisplayName() });
073        }
074    
075        public void renderContribution(IMarkupWriter writer, IRequestCycle cycle,
076                FormComponentContributorContext context, IFormComponent field)
077        {
078            context.includeClasspathScript("/org/apache/tapestry/form/validator/StringValidator.js");
079    
080            StringBuffer buffer = new StringBuffer("function(event) { Tapestry.validate_min_length(event, '");
081            buffer.append(field.getClientId());
082            buffer.append("', ");
083            buffer.append(_minLength);
084            buffer.append(", ");
085            buffer.append(TapestryUtils.enquote(buildMessage(context, field)));
086            buffer.append("); }");
087    
088            context.addSubmitHandler(buffer.toString());
089        }
090    }