/*
* =============================================================================
*
* Copyright (c) 2011-2014, 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.expression;
import java.util.regex.Matcher;
import java.util.regex.Pattern;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.thymeleaf.Configuration;
import org.thymeleaf.TemplateEngine;
import org.thymeleaf.context.IProcessingContext;
import org.thymeleaf.exceptions.TemplateProcessingException;
import org.thymeleaf.util.Validate;
/**
*
* @author Daniel Fernández
*
* @since 1.1
*
*/
public final class SelectionVariableExpression extends SimpleExpression {
private static final Logger logger = LoggerFactory.getLogger(SelectionVariableExpression.class);
private static final long serialVersionUID = 854441190427550056L;
static final char SELECTOR = '*';
private static final Pattern SELECTION_VAR_PATTERN =
Pattern.compile("^\\s*\\*\\{(.+?)\\}\\s*$", Pattern.DOTALL);
private final String expression;
private final boolean convertToString;
public SelectionVariableExpression(final String expression) {
this(expression, false);
}
/**
* @since 2.1.0
*/
public SelectionVariableExpression(final String expression, final boolean convertToString) {
super();
Validate.notNull(expression, "Expression cannot be null");
this.expression = expression;
this.convertToString = convertToString;
}
public String getExpression() {
return this.expression;
}
/**
* @since 2.1.0
*/
public boolean getConvertToString() {
return this.convertToString;
}
@Override
public String getStringRepresentation() {
return String.valueOf(SELECTOR) +
String.valueOf(SimpleExpression.EXPRESSION_START_CHAR) +
(this.convertToString? String.valueOf(SimpleExpression.EXPRESSION_START_CHAR) : "") +
this.expression +
(this.convertToString? String.valueOf(SimpleExpression.EXPRESSION_END_CHAR) : "") +
String.valueOf(SimpleExpression.EXPRESSION_END_CHAR);
}
static SelectionVariableExpression parseSelectionVariable(final String input) {
final Matcher matcher = SELECTION_VAR_PATTERN.matcher(input);
if (!matcher.matches()) {
return null;
}
final String expression = matcher.group(1);
final int expressionLen = expression.length();
if (expressionLen > 2 &&
expression.charAt(0) == SimpleExpression.EXPRESSION_START_CHAR &&
expression.charAt(expressionLen - 1) == SimpleExpression.EXPRESSION_END_CHAR) {
// Double brackets = enable to-String conversion
return new SelectionVariableExpression(expression.substring(1, expressionLen - 1), true);
}
return new SelectionVariableExpression(expression, false);
}
static Object executeSelectionVariable(final Configuration configuration,
final IProcessingContext processingContext, final SelectionVariableExpression expression,
final IStandardVariableExpressionEvaluator expressionEvaluator,
final StandardExpressionExecutionContext expContext) {
if (logger.isTraceEnabled()) {
logger.trace("[THYMELEAF][{}] Evaluating selection variable expression: \"{}\"", TemplateEngine.threadIndex(), expression.getStringRepresentation());
}
final String exp = expression.getExpression();
if (exp == null) {
throw new TemplateProcessingException(
"Variable expression is null, which is not allowed");
}
final StandardExpressionExecutionContext evalExpContext =
(expression.getConvertToString()? expContext.withTypeConversion() : expContext.withoutTypeConversion());
return expressionEvaluator.evaluate(configuration, processingContext, exp, evalExpContext, true);
}
}