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/*
* =============================================================================
*
* 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.spring4.util;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.Collections;
import java.util.List;
import org.springframework.beans.NotReadablePropertyException;
import org.springframework.util.StringUtils;
import org.springframework.validation.Errors;
import org.springframework.validation.FieldError;
import org.springframework.validation.ObjectError;
import org.springframework.web.servlet.support.BindStatus;
import org.springframework.web.servlet.support.RequestContext;
import org.thymeleaf.IEngineConfiguration;
import org.thymeleaf.context.IProcessingContext;
import org.thymeleaf.exceptions.TemplateProcessingException;
import org.thymeleaf.spring4.naming.SpringContextVariableNames;
import org.thymeleaf.standard.expression.IStandardExpression;
import org.thymeleaf.standard.expression.IStandardExpressionParser;
import org.thymeleaf.standard.expression.SelectionVariableExpression;
import org.thymeleaf.standard.expression.StandardExpressions;
import org.thymeleaf.standard.expression.VariableExpression;
import org.thymeleaf.util.Validate;
/**
*
* @author Daniel Fernández
* @author Tobias Gafner
*
* @since 1.0 (reimplemented in 3.0.0)
*
*/
public final class FieldUtils {
public static final String ALL_FIELDS = "*";
public static final String GLOBAL_EXPRESSION = "global";
public static final String ALL_EXPRESSION = "all";
public static boolean hasErrors(final IProcessingContext processingContext, final String field) {
return checkErrors(processingContext, convertToFieldExpression(field));
}
public static boolean hasAnyErrors(final IProcessingContext processingContext) {
return checkErrors(processingContext, ALL_EXPRESSION);
}
public static boolean hasGlobalErrors(final IProcessingContext processingContext) {
return checkErrors(processingContext, GLOBAL_EXPRESSION);
}
public static List errors(final IProcessingContext processingContext, final String field) {
return computeErrors(processingContext, convertToFieldExpression(field));
}
public static List errors(final IProcessingContext processingContext) {
return computeErrors(processingContext, ALL_EXPRESSION);
}
public static List globalErrors(final IProcessingContext processingContext) {
return computeErrors(processingContext, GLOBAL_EXPRESSION);
}
private static List computeErrors(final IProcessingContext processingContext, final String fieldExpression) {
final BindStatus bindStatus = FieldUtils.getBindStatus(processingContext, fieldExpression);
if (bindStatus == null) {
return Collections.EMPTY_LIST;
}
final String[] errorCodes = bindStatus.getErrorMessages();
if (errorCodes == null || errorCodes.length == 0) {
// If we don't need a new object, we avoid creating it
return Collections.EMPTY_LIST;
}
return Arrays.asList(errorCodes);
}
public static List detailedErrors(final IProcessingContext processingContext) {
return computeDetailedErrors(processingContext, ALL_EXPRESSION, true, true);
}
private static List computeDetailedErrors(
final IProcessingContext processingContext, final String fieldExpression,
final boolean includeGlobalErrors, final boolean includeFieldErrors) {
final BindStatus bindStatus =
FieldUtils.getBindStatus(processingContext, fieldExpression);
if (bindStatus == null) {
return Collections.EMPTY_LIST;
}
final Errors errors = bindStatus.getErrors();
if (errors == null) {
return Collections.EMPTY_LIST;
}
final RequestContext requestContext =
(RequestContext) processingContext.getVariables().getVariable(SpringContextVariableNames.SPRING_REQUEST_CONTEXT);
if (requestContext == null) {
return Collections.EMPTY_LIST;
}
// We will try to avoid creating the List if we don't need it
List errorObjects = null;
if (includeGlobalErrors) {
final List globalErrors = errors.getGlobalErrors();
for (final ObjectError globalError : globalErrors) {
final String message = requestContext.getMessage(globalError, false);
final DetailedError errorObject =
new DetailedError(globalError.getCode(), globalError.getArguments(), message);
if (errorObjects == null) {
errorObjects = new ArrayList(errors.getErrorCount() + 2);
}
errorObjects.add(errorObject);
}
}
if (includeFieldErrors) {
final List fieldErrors = errors.getFieldErrors();
for (final FieldError fieldError : fieldErrors) {
final String message = requestContext.getMessage(fieldError, false);
final DetailedError errorObject =
new DetailedError(fieldError.getField(), fieldError.getCode(), fieldError.getArguments(), message);
if (errorObjects == null) {
errorObjects = new ArrayList(errors.getErrorCount() + 2);
}
errorObjects.add(errorObject);
}
}
if (errorObjects == null) {
return Collections.EMPTY_LIST;
}
return errorObjects;
}
public static String idFromName(final String fieldName) {
return StringUtils.deleteAny(fieldName, "[]");
}
private static String convertToFieldExpression(final String field) {
if (field == null) {
return null;
}
final String trimmedField = field.trim();
if (trimmedField.length() == 0) {
return null;
}
final char firstc = trimmedField.charAt(0);
if (firstc == '*' || firstc == '$') {
return field;
}
return "*{" + field + "}";
}
private static boolean checkErrors(final IProcessingContext processingContext, final String expression) {
final BindStatus bindStatus = FieldUtils.getBindStatus(processingContext, expression);
return bindStatus.isError();
}
public static BindStatus getBindStatus(final IProcessingContext processingContext, final String expression) {
return getBindStatus(processingContext, false, expression);
}
public static BindStatus getBindStatus(
final IProcessingContext processingContext, final boolean optional, final String expression) {
Validate.notNull(expression, "Expression cannot be null");
if (GLOBAL_EXPRESSION.equals(expression) || ALL_EXPRESSION.equals(expression) || ALL_FIELDS.equals(expression)) {
// If "global", "all" or "*" are used without prefix, they must be inside a form, so we add *{...}
final String completeExpression = "*{" + expression + "}";
return getBindStatus(processingContext, optional, completeExpression);
}
final IEngineConfiguration configuration = processingContext.getConfiguration();
final IStandardExpressionParser expressionParser = StandardExpressions.getExpressionParser(configuration);
final IStandardExpression expressionObj = expressionParser.parseExpression(processingContext, expression);
if (expressionObj == null) {
throw new TemplateProcessingException(
"Expression \"" + expression + "\" is not valid: cannot perform Spring bind");
}
if (expressionObj instanceof SelectionVariableExpression) {
final String bindExpression = ((SelectionVariableExpression)expressionObj).getExpression();
return getBindStatusFromParsedExpression(processingContext, optional, true, bindExpression);
}
if (expressionObj instanceof VariableExpression) {
final String bindExpression = ((VariableExpression)expressionObj).getExpression();
return getBindStatusFromParsedExpression(processingContext, optional, false, bindExpression);
}
throw new TemplateProcessingException(
"Expression \"" + expression + "\" is not valid: only variable expressions ${...} or " +
"selection expressions *{...} are allowed in Spring field bindings");
}
public static BindStatus getBindStatusFromParsedExpression(
final IProcessingContext processingContext,
final boolean useSelectionAsRoot, final String expression) {
return getBindStatusFromParsedExpression(
processingContext, false, useSelectionAsRoot, expression);
}
public static BindStatus getBindStatusFromParsedExpression(
final IProcessingContext processingContext,
final boolean optional, final boolean useSelectionAsRoot, final String expression) {
/*
* This version of the getBindStatus method should only be called after parsing, and therefore the
* passed expression must be a fragment of the already parsed expression. Note this is important because
* this method performs no preprocessing on the expression!
*/
// This method will return null if no binding is found and optional == true
final RequestContext requestContext =
(RequestContext) processingContext.getVariables().getVariable(SpringContextVariableNames.SPRING_REQUEST_CONTEXT);
if (requestContext == null) {
return null;
}
final String completeExpression =
FieldUtils.validateAndGetValueExpression(processingContext, useSelectionAsRoot, expression);
if (completeExpression == null) {
return null;
}
if (!optional) {
return new BindStatus(requestContext, completeExpression, false);
}
if (isBound(requestContext, completeExpression)) {
// Creating an instance of BindStatus for an unbound object results in an (expensive) exception,
// so we avoid it by checking first. Because the check is a simplification, we still handle the exception.
try {
return new BindStatus(requestContext, completeExpression, false);
} catch (final NotReadablePropertyException ignored) {
return null;
}
}
return null;
}
private static String validateAndGetValueExpression(
final IProcessingContext processingContext, final boolean useSelectionAsRoot, final String expression) {
/*
* Only asterisk syntax (selection variable expressions) are allowed here.
*/
if (useSelectionAsRoot) {
VariableExpression boundObjectValue =
(VariableExpression) processingContext.getVariables().getVariable(SpringContextVariableNames.SPRING_BOUND_OBJECT_EXPRESSION);
final String boundObjectExpression =
(boundObjectValue == null? null : boundObjectValue.getExpression());
if (GLOBAL_EXPRESSION.equals(expression)) {
// Should return null if no object previously bound: nothing to apply 'global' on!
if (boundObjectExpression == null) {
return null;
}
return boundObjectExpression;
}
if (ALL_EXPRESSION.equals(expression) || ALL_FIELDS.equals(expression)) {
// Should return null if no object previously bound: nothing to apply '*' on!
if (boundObjectExpression == null) {
return null;
}
return boundObjectExpression + "." + ALL_FIELDS;
}
if (boundObjectExpression == null) {
return expression;
}
return boundObjectExpression + "." + expression;
}
return expression;
}
private static boolean isBound(final RequestContext requestContext, final String completeExpression) {
final int dotPos = completeExpression.indexOf('.');
if (dotPos == -1) { // Spring only allows second-level binding for conversions! ("x.y", not "x")
return false;
}
// The bound bean name is everything before the first dot (or everything, if no dot present)
final String beanName = completeExpression.substring(0, dotPos);
// The getErrors() method is not extremely efficient, but it has a cache map, so it should be fine
final boolean beanValid = requestContext.getErrors(beanName, false) != null;
if (beanValid && completeExpression.length() > dotPos) {
final String path = completeExpression.substring(dotPos + 1, completeExpression.length() - 1);
// We will validate the rest of the expression as a bean property identifier or a bean property expression.
return validateBeanPath(path);
}
return false;
}
/*
* This method determines whether a fragment of a bean path is a valid bean property identifier
* or bean property expression.
*/
private static boolean validateBeanPath(final CharSequence path) {
final int pathLen = path.length();
for (int charPos = 0; charPos < pathLen; charPos++) {
final char c = path.charAt(charPos);
if (!Character.isJavaIdentifierPart(c) || c == '.') {
return false;
}
}
return true;
}
private FieldUtils() {
super();
}
}