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.translator;
016    
017    import java.util.Locale;
018    
019    import org.apache.hivemind.HiveMind;
020    import org.apache.tapestry.IMarkupWriter;
021    import org.apache.tapestry.IRequestCycle;
022    import org.apache.tapestry.form.AbstractFormComponentContributor;
023    import org.apache.tapestry.form.FormComponentContributorContext;
024    import org.apache.tapestry.form.IFormComponent;
025    import org.apache.tapestry.form.ValidationMessages;
026    import org.apache.tapestry.valid.ValidatorException;
027    
028    /**
029     * Abstract {@link Translator} implementation that provides default behavior for trimming, null
030     * object, and empty text handling.
031     * 
032     * @author Paul Ferraro
033     * @since 4.0
034     */
035    public abstract class AbstractTranslator extends AbstractFormComponentContributor implements
036            Translator
037    {
038        private boolean _trim;
039    
040        private String _message;
041    
042        public AbstractTranslator()
043        {
044        }
045    
046        // Needed until HIVEMIND-134 fix is available
047        public AbstractTranslator(String initializer)
048        {
049            super(initializer);
050        }
051    
052        /**
053         * @see org.apache.tapestry.form.translator.Translator#format(org.apache.tapestry.form.IFormComponent,
054         *      Locale, java.lang.Object)
055         */
056        public String format(IFormComponent field, Locale locale, Object object)
057        {
058            if (object == null)
059                return "";
060    
061            return formatObject(field, locale, object);
062        }
063    
064        /**
065         * @see org.apache.tapestry.form.translator.Translator#parse(org.apache.tapestry.form.IFormComponent,
066         *      ValidationMessages, java.lang.String)
067         */
068        public Object parse(IFormComponent field, ValidationMessages messages, String text)
069                throws ValidatorException
070        {
071            String value = text == null ? null : (_trim ? text.trim() : text);
072    
073            return HiveMind.isBlank(value) ? getValueForEmptyInput()
074                    : parseText(field, messages, value);
075        }
076    
077        protected abstract String formatObject(IFormComponent field, Locale locale, Object object);
078    
079        protected abstract Object parseText(IFormComponent field, ValidationMessages messages,
080                String text) throws ValidatorException;
081    
082        /**
083         * The value to be used when the value supplied in the request is blank (null or empty). The
084         * default value is null, but some subclasses may override.
085         * 
086         * @see #parse(IFormComponent, ValidationMessages, String)
087         * @return null, subclasses may override
088         */
089        protected Object getValueForEmptyInput()
090        {
091            return null;
092        }
093    
094        protected String buildMessage(ValidationMessages messages, IFormComponent field, String key)
095        {
096            String label = field.getDisplayName();
097    
098            Object[] parameters = getMessageParameters(messages.getLocale(), label);
099    
100            return messages.formatValidationMessage(_message, key, parameters);
101        }
102    
103        protected Object[] getMessageParameters(Locale locale, String label)
104        {
105            return new Object[]
106            { label };
107        }
108    
109        /**
110         * @see org.apache.tapestry.form.FormComponentContributor#renderContribution(org.apache.tapestry.IRequestCycle,
111         *      org.apache.tapestry.form.IFormComponent)
112         */
113        public void renderContribution(IMarkupWriter writer, IRequestCycle cycle,
114                FormComponentContributorContext context, IFormComponent field)
115        {
116            super.renderContribution(writer, cycle, context, field);
117    
118            if (_trim)
119                context.addSubmitHandler("function (event) { Tapestry.trim_field_value('"
120                        + field.getClientId() + "'); }");
121        }
122    
123        public boolean isTrim()
124    
125        {
126            return _trim;
127        }
128    
129        public void setTrim(boolean trim)
130        {
131            _trim = trim;
132        }
133    
134        public String getMessage()
135        {
136            return _message;
137        }
138    
139        public void setMessage(String message)
140        {
141            _message = message;
142        }
143    }