/*
* =============================================================================
*
* Copyright (c) 2011-2016, The THYMELEAF team (http://www.thymeleaf.org)
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*
* =============================================================================
*/
package org.thymeleaf.standard.processor;
import org.attoparser.util.TextUtil;
import org.thymeleaf.context.ITemplateContext;
import org.thymeleaf.engine.AttributeName;
import org.thymeleaf.exceptions.TemplateProcessingException;
import org.thymeleaf.model.IAttribute;
import org.thymeleaf.model.IProcessableElementTag;
import org.thymeleaf.processor.AbstractProcessor;
import org.thymeleaf.processor.element.IElementTagProcessor;
import org.thymeleaf.processor.element.IElementTagStructureHandler;
import org.thymeleaf.processor.element.MatchingAttributeName;
import org.thymeleaf.processor.element.MatchingElementName;
import org.thymeleaf.standard.expression.FragmentExpression;
import org.thymeleaf.standard.expression.IStandardExpression;
import org.thymeleaf.standard.expression.IStandardExpressionParser;
import org.thymeleaf.standard.expression.NoOpToken;
import org.thymeleaf.standard.expression.StandardExpressionExecutionContext;
import org.thymeleaf.standard.expression.StandardExpressions;
import org.thymeleaf.templatemode.TemplateMode;
import org.thymeleaf.util.EscapedAttributeUtils;
import org.unbescape.html.HtmlEscape;
/**
*
* @author Daniel Fernández
*
* @since 3.0.0
*
*/
public final class StandardDefaultAttributesTagProcessor
extends AbstractProcessor implements IElementTagProcessor {
// Setting to Integer.MAX_VALUE is alright - we will always be limited by the dialect precedence anyway
public static final int PRECEDENCE = Integer.MAX_VALUE;
private final String dialectPrefix;
private final MatchingAttributeName matchingAttributeName;
public StandardDefaultAttributesTagProcessor(final TemplateMode templateMode, final String dialectPrefix) {
super(templateMode, PRECEDENCE);
this.dialectPrefix = dialectPrefix;
this.matchingAttributeName = MatchingAttributeName.forAllAttributesWithPrefix(getTemplateMode(), dialectPrefix);
}
public final MatchingElementName getMatchingElementName() {
return null;
}
public final MatchingAttributeName getMatchingAttributeName() {
return this.matchingAttributeName;
}
// Default implementation - meant to be overridden by subclasses if needed
public void process(
final ITemplateContext context,
final IProcessableElementTag tag,
final IElementTagStructureHandler structureHandler) {
final TemplateMode templateMode = getTemplateMode();
final IAttribute[] attributes = tag.getAllAttributes();
// Should be no problem in performing modifications during iteration, as the attributeNames list
// should not be affected by modifications on the original tag attribute set
for (final IAttribute attribute : attributes) {
final AttributeName attributeName = attribute.getAttributeDefinition().getAttributeName();
if (attributeName.isPrefixed()) {
if (TextUtil.equals(templateMode.isCaseSensitive(), attributeName.getPrefix(), this.dialectPrefix)) {
// We will process each 'default' attribute separately
processDefaultAttribute(context, tag, attribute, structureHandler);
}
}
}
}
private static void processDefaultAttribute(
final ITemplateContext context,
final IProcessableElementTag tag, final IAttribute attribute,
final IElementTagStructureHandler structureHandler) {
try {
final AttributeName attributeName = attribute.getAttributeDefinition().getAttributeName();
final String attributeValue =
EscapedAttributeUtils.unescapeAttribute(context.getTemplateMode(), attribute.getValue());
/*
* Compute the new attribute name (i.e. the same, without the prefix)
*/
final String originalCompleteAttributeName = attribute.getAttributeCompleteName();
final String canonicalAttributeName = attributeName.getAttributeName();
final String newAttributeName;
if (TextUtil.endsWith(true, originalCompleteAttributeName, canonicalAttributeName)) {
newAttributeName = canonicalAttributeName; // We avoid creating a new String instance
} else {
newAttributeName =
originalCompleteAttributeName.substring(originalCompleteAttributeName.length() - canonicalAttributeName.length());
}
/*
* Obtain the parser
*/
final IStandardExpressionParser expressionParser = StandardExpressions.getExpressionParser(context.getConfiguration());
/*
* Execute the expression, handling nulls in a way consistent with the rest of the Standard Dialect
*/
final Object expressionResult;
if (attributeValue != null) {
final IStandardExpression expression = expressionParser.parseExpression(context, attributeValue);
if (expression != null && expression instanceof FragmentExpression) {
// This is merely a FragmentExpression (not complex, not combined with anything), so we can apply a shortcut
// so that we don't require a "null" result for this expression if the template does not exist. That will
// save a call to resource.exists() which might be costly.
final FragmentExpression.ExecutedFragmentExpression executedFragmentExpression =
FragmentExpression.createExecutedFragmentExpression(context, (FragmentExpression) expression, StandardExpressionExecutionContext.NORMAL);
expressionResult =
FragmentExpression.resolveExecutedFragmentExpression(context, executedFragmentExpression, true);
} else {
expressionResult = expression.execute(context);
}
} else {
expressionResult = null;
}
/*
* If the result of this expression is NO-OP, there is nothing to execute
*/
if (expressionResult == NoOpToken.VALUE) {
structureHandler.removeAttribute(attributeName);
return;
}
/*
* Compute the new attribute value
*/
final String newAttributeValue = HtmlEscape.escapeHtml4Xml(expressionResult == null ? null : expressionResult.toString());
/*
* Set the new value, removing the attribute completely if the expression evaluated to null
*/
if (newAttributeValue == null || newAttributeValue.length() == 0) {
// We are removing the equivalent attribute name, without the prefix...
structureHandler.removeAttribute(newAttributeName);
structureHandler.removeAttribute(attributeName);
} else {
// We are setting the equivalent attribute name, without the prefix...
structureHandler.replaceAttribute(attributeName, newAttributeName, (newAttributeValue == null? "" : newAttributeValue));
}
} catch (final TemplateProcessingException e) {
// This is a nice moment to check whether the execution raised an error and, if so, add location information
// Note this is similar to what is done at the superclass AbstractElementTagProcessor, but we can be more
// specific because we know exactly what attribute was being executed and caused the error
if (!e.hasTemplateName()) {
e.setTemplateName(tag.getTemplateName());
}
if (!e.hasLineAndCol()) {
e.setLineAndCol(attribute.getLine(), attribute.getCol());
}
throw e;
} catch (final Exception e) {
throw new TemplateProcessingException(
"Error during execution of processor '" + StandardDefaultAttributesTagProcessor.class.getName() + "'",
tag.getTemplateName(), attribute.getLine(), attribute.getCol(), e);
}
}
}