/*
* [The "BSD licence"]
* Copyright (c) 2013-2014 Dandelion
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. Neither the name of Dandelion nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
* IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
package com.github.dandelion.datatables.thymeleaf.util;
import java.util.regex.Pattern;
import org.thymeleaf.Arguments;
import org.thymeleaf.Configuration;
import org.thymeleaf.dom.Element;
import org.thymeleaf.standard.expression.IStandardExpression;
import org.thymeleaf.standard.expression.IStandardExpressionParser;
import org.thymeleaf.standard.expression.StandardExpressions;
import com.github.dandelion.datatables.core.ajax.ColumnDef.SortDirection;
import com.github.dandelion.datatables.core.export.HttpMethod;
import com.github.dandelion.datatables.core.extension.feature.FilterPlaceholder;
import com.github.dandelion.datatables.core.extension.feature.FilterType;
import com.github.dandelion.datatables.core.extension.feature.PaginationType;
import com.github.dandelion.datatables.core.extension.feature.SortType;
import com.github.dandelion.datatables.core.extension.theme.Theme;
import com.github.dandelion.datatables.core.extension.theme.ThemeOption;
/**
* General utility methods used in the Dandelion-Datatables dialect.
*
* @author Thibault Duchateau
* @author Pavel Janecka
* @author Gautier Dhordain
*/
public class AttributeUtils {
private static Pattern booleanRegex = Pattern.compile("^true|false$");
private static Pattern stringRegex;
static {
stringRegex = generateStringRegexFromEnumerations(
SortDirection.class,
Theme.class,
ThemeOption.class,
FilterPlaceholder.class,
FilterType.class,
PaginationType.class,
SortType.class,
HttpMethod.class);
}
private static Pattern generateStringRegexFromEnumerations(Class<?>... enumClasses) {
boolean firstElement = true;
StringBuilder enumRegexBuilder = new StringBuilder();
StringBuilder finalRegexBuilder = new StringBuilder();
for (Class<?> enumClass : enumClasses) {
for (Object enumCst : enumClass.getEnumConstants()) {
if (firstElement) {
firstElement = false;
} else {
enumRegexBuilder.append('|');
}
String enumName = ((Enum<?>) enumCst).name().toLowerCase();
enumRegexBuilder.append(enumName);
}
}
finalRegexBuilder
.append("^(")
.append(enumRegexBuilder)
.append(")(,(")
.append(enumRegexBuilder)
.append("))*$");
return Pattern.compile(finalRegexBuilder.toString(), Pattern.CASE_INSENSITIVE);
}
/**
* Parse an attribute's value of Boolean class.
*
* @param arguments
* Thymeleaf {@link Arguments}
* @param value
* The expression to parse
* @param clazz
* {@link Class} of the attribute's value
* @return A Boolean which is evaluated :
* <ul>
* <li>either using the "true" or "false" strings</li>
* <li>or using the default value if the expression to parse is null
* </li>
* <li>or using the Standard Thymeleaf Expression in all other cases
* </li>
* </ul>
*/
public static Boolean parseBooleanAttribute(Arguments arguments, Element element, String attributeName) {
String value = element.getAttributeValue(attributeName);
// Handling null value
if (value == null) {
return null;
}
if (booleanRegex.matcher(value).find()) {
return Boolean.parseBoolean(value.trim().toLowerCase());
}
// Default behaviour
return processStandardExpression(arguments, value, Boolean.class);
}
/**
* Parse an attribute's value of String class.
*
* @param arguments
* Thymeleaf {@link Arguments}
* @param value
* The expression to parse
* @param defaultValue
* The default value
* @param clazz
* {@link Class} of the attribute's value
* @return A string which is evaluated :
* <ul>
* <li>either using a specific case (e.g. asc/desc)</li>
* <li>or using the default value if the expression to parse is null
* </li>
* <li>or using the Standard Thymeleaf Expression in all other cases
* </li>
* </ul>
*/
public static String parseStringAttribute(Arguments arguments, Element element, String attributeName) {
String value = element.getAttributeValue(attributeName);
// Handling null value
if (value == null) {
return null;
}
if (stringRegex.matcher(value.trim().toLowerCase()).find()) {
return value.trim().toLowerCase();
}
// Default behaviour
return processStandardExpression(arguments, value, String.class);
}
/**
* Parse an attribute's value of any class.
*
* @param arguments
* Thymeleaf {@link Arguments}
* @param value
* The expression to parse
* @param clazz
* {@link Class} of the attribute's value
* @return the default value if the expression to parse is null or the value
* of the Thymeleaf Standard expression processing.
*/
public static <T> T parseAttribute(Arguments arguments, Element element, String attributeName, Class<T> clazz) {
String value = element.getAttributeValue(attributeName);
// Handling null value
if (value == null) {
return null;
}
// Default behaviour
return processStandardExpression(arguments, value, clazz);
}
/**
* Process the Thymelead Standard Expression processor on an expression.
*
* @param arguments
* Thymeleaf {@link Arguments}
* @param value
* String expression to parse
* @param clazz
* {@link Class} of the attribute's value
* @return an object processed by the Thymeleaf Standard Expression
* processor.
*/
@SuppressWarnings("unchecked")
private static <T> T processStandardExpression(Arguments arguments, String value, Class<T> clazz) {
// Use the Thymeleaf Standard expression processor on the expression
Object result = null;
if (value.contains("${") || value.contains("@{") || value.contains("#{")) {
Configuration configuration = arguments.getConfiguration();
IStandardExpressionParser expressionParser = StandardExpressions.getExpressionParser(configuration);
IStandardExpression standardExpression = expressionParser.parseExpression(configuration, arguments, value);
result = standardExpression.execute(configuration, arguments);
}
else {
result = value;
}
// Handling null value
if (result == null) {
return null;
}
T tmpValue = null;
// Typing the result
if (clazz.isAssignableFrom(result.getClass())) {
tmpValue = (T) result;
}
// Handling default value
return tmpValue;
}
}