com.github.dandelion.datatables.thymeleaf.util.AttributeUtils Maven / Gradle / Ivy
/*
* [The "BSD licence"]
* Copyright (c) 2013-2015 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,
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* 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.StandardExpressionParserWrapper;
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.PagingType;
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;
import com.github.dandelion.datatables.core.generator.YadcfConfigGenerator.FilterType;
/**
*
* Set of utilities 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$");
private static Pattern stringRegex;
static {
stringRegex = generateStringRegexFromEnumerations(SortDirection.class, Theme.class, ThemeOption.class,
FilterPlaceholder.class, FilterType.class, PagingType.class, SortType.class, HttpMethod.class);
}
private static Pattern generateStringRegexFromEnumerations(Class... enumClasses) {
boolean firstElement = true;
StringBuilder enumRegexBuilder = new StringBuilder();
StringBuilder finalRegexBuilder = new StringBuilder();
for (Class enumClass : enumClasses) {
for (Object enumCst : enumClass.getEnumConstants()) {
if (firstElement) {
firstElement = false;
}
else {
enumRegexBuilder.append('|');
}
String enumName = ((Enum) enumCst).name().toLowerCase();
enumRegexBuilder.append(enumName);
}
}
finalRegexBuilder.append("^(").append(enumRegexBuilder).append(")(,(").append(enumRegexBuilder).append("))*$");
return Pattern.compile(finalRegexBuilder.toString(), Pattern.CASE_INSENSITIVE);
}
/**
*
* Parses the value of an attribute as a {@link Boolean}.
*
*
* @param arguments
* Thymeleaf {@link Arguments}
* @param element
* The element in which an attribute is to be parsed.
* @param attributeName
* The attribute name for which the value is to be parsed.
* @return A Boolean which is evaluated :
*
* - either using the "true" or "false" strings
* - or using the default value if the expression to parse is null
* - or using the Standard Thymeleaf Expression in all other cases
*
*/
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);
}
/**
*
* Parses the value of an attribute as a {@link String}.
*
*
* @param arguments
* Thymeleaf {@link Arguments}
* @param element
* The element in which an attribute is to be parsed.
* @param attributeName
* The attribute name for which the value is to be parsed.
* @return A string which is evaluated :
*
* - either using a specific case (e.g. asc/desc)
* - or using the default value if the expression to parse is null
* - or using the Standard Thymeleaf Expression in all other cases
*
*/
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);
}
/**
*
* Parses the value of an attribute according to the provided {@code clazz}.
*
*
* @param arguments
* Thymeleaf {@link Arguments}
* @param element
* The element in which an attribute is to be parsed.
* @param attributeName
* The attribute name for which the value is to be parsed.
* @param clazz
* The {@link Class} in which the value of the given attribute name
* is to be parsed.
* @return the default value if the expression to parse is null or the value
* of the Thymeleaf Standard expression processing.
*/
public static T parseAttribute(Arguments arguments, Element element, String attributeName, Class clazz) {
String value = element.getAttributeValue(attributeName);
// Handling null value
if (value == null) {
return null;
}
// Default behaviour
return processStandardExpression(arguments, value, clazz);
}
/**
*
* Processes the provided value using the Thymeleaf Standard Expression
* processor.
*
*
* @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 processStandardExpression(Arguments arguments, String value, Class clazz) {
Object result = null;
Configuration configuration = arguments.getConfiguration();
StandardExpressionParserWrapper expressionParser = new StandardExpressionParserWrapper();
IStandardExpression standardExpression = expressionParser.parseExpression(configuration, arguments, value);
if (standardExpression == null) {
result = value;
}
else {
result = standardExpression.execute(configuration, arguments);
}
// Handling null value
if (result == null) {
return null;
}
return clazz.isAssignableFrom(result.getClass()) ? (T) result : null;
}
}