org.thymeleaf.spring5.dialect.SpringStandardDialect Maven / Gradle / Ivy
Show all versions of thymeleaf-spring5 Show documentation
/*
* =============================================================================
*
* Copyright (c) 2011-2018, 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.spring5.dialect;
import java.util.Collections;
import java.util.LinkedHashSet;
import java.util.Map;
import java.util.Set;
import java.util.function.Function;
import org.springframework.web.server.ServerWebExchange;
import org.thymeleaf.expression.IExpressionObjectFactory;
import org.thymeleaf.processor.IProcessor;
import org.thymeleaf.spring5.SpringTemplateEngine;
import org.thymeleaf.spring5.context.SpringContextUtils;
import org.thymeleaf.spring5.expression.SPELVariableExpressionEvaluator;
import org.thymeleaf.spring5.expression.SpringStandardConversionService;
import org.thymeleaf.spring5.expression.SpringStandardExpressionObjectFactory;
import org.thymeleaf.spring5.expression.SpringStandardExpressions;
import org.thymeleaf.spring5.processor.SpringActionTagProcessor;
import org.thymeleaf.spring5.processor.SpringErrorClassTagProcessor;
import org.thymeleaf.spring5.processor.SpringErrorsTagProcessor;
import org.thymeleaf.spring5.processor.SpringHrefTagProcessor;
import org.thymeleaf.spring5.processor.SpringInputCheckboxFieldTagProcessor;
import org.thymeleaf.spring5.processor.SpringInputFileFieldTagProcessor;
import org.thymeleaf.spring5.processor.SpringInputGeneralFieldTagProcessor;
import org.thymeleaf.spring5.processor.SpringInputPasswordFieldTagProcessor;
import org.thymeleaf.spring5.processor.SpringInputRadioFieldTagProcessor;
import org.thymeleaf.spring5.processor.SpringMethodTagProcessor;
import org.thymeleaf.spring5.processor.SpringObjectTagProcessor;
import org.thymeleaf.spring5.processor.SpringOptionFieldTagProcessor;
import org.thymeleaf.spring5.processor.SpringOptionInSelectFieldTagProcessor;
import org.thymeleaf.spring5.processor.SpringSelectFieldTagProcessor;
import org.thymeleaf.spring5.processor.SpringSrcTagProcessor;
import org.thymeleaf.spring5.processor.SpringTextareaFieldTagProcessor;
import org.thymeleaf.spring5.processor.SpringUErrorsTagProcessor;
import org.thymeleaf.spring5.processor.SpringValueTagProcessor;
import org.thymeleaf.spring5.util.SpringVersionUtils;
import org.thymeleaf.standard.StandardDialect;
import org.thymeleaf.standard.expression.IStandardConversionService;
import org.thymeleaf.standard.expression.IStandardVariableExpressionEvaluator;
import org.thymeleaf.standard.processor.StandardActionTagProcessor;
import org.thymeleaf.standard.processor.StandardHrefTagProcessor;
import org.thymeleaf.standard.processor.StandardMethodTagProcessor;
import org.thymeleaf.standard.processor.StandardObjectTagProcessor;
import org.thymeleaf.standard.processor.StandardSrcTagProcessor;
import org.thymeleaf.standard.processor.StandardValueTagProcessor;
import org.thymeleaf.templatemode.TemplateMode;
/**
*
* SpringStandard Dialect. This is the class containing the implementation of Thymeleaf Standard Dialect, including all
* {@code th:*} processors, expression objects, etc. for Spring-enabled environments.
*
*
* This dialect is valid both for Spring WebMVC and Spring WebFlux environments.
*
*
* Note this dialect uses SpringEL as an expression language and adds some Spring-specific
* features on top of {@link StandardDialect}, like {@code th:field} or Spring-related expression objects.
*
*
* The usual and recommended way of using this dialect is by instancing {@link SpringTemplateEngine}
* instead of {@link org.thymeleaf.TemplateEngine}. The former will automatically add this dialect and perform
* some specific configuration like e.g. Spring-integrated message resolution.
*
*
* Note a class with this name existed since 1.0, but it was completely reimplemented
* in Thymeleaf 3.0
*
*
* @author Daniel Fernández
*
* @since 3.0.3
*
*/
public class SpringStandardDialect extends StandardDialect {
public static final String NAME = "SpringStandard";
public static final String PREFIX = "th";
public static final int PROCESSOR_PRECEDENCE = 1000;
public static final boolean DEFAULT_ENABLE_SPRING_EL_COMPILER = false;
public static final boolean DEFAULT_RENDER_HIDDEN_MARKERS_BEFORE_CHECKBOXES = false;
private boolean enableSpringELCompiler = DEFAULT_ENABLE_SPRING_EL_COMPILER;
private boolean renderHiddenMarkersBeforeCheckboxes = DEFAULT_RENDER_HIDDEN_MARKERS_BEFORE_CHECKBOXES;
private static final Map REACTIVE_MODEL_ADDITIONS_EXECUTION_ATTRIBUTES;
// This execution attribute will force the asynchronous resolution of the WebSession (not the real creation of a
// persisted session) before view execution. This will avoid the need to block in order to obtain the WebSession
// from the ServerWebExchange during template execution.
// NOTE here we are not using the constant from the ReactiveThymeleafView class (instead we replicate its same
// value "ThymeleafReactiveModelAdditions:" so that we don't force the initialisation of that class in
// non-WebFlux environments.
private static final String WEB_SESSION_EXECUTION_ATTRIBUTE_NAME =
"ThymeleafReactiveModelAdditions:" + SpringContextUtils.WEB_SESSION_ATTRIBUTE_NAME;
// These variables will be initialized lazily following the model applied in the extended StandardDialect.
private IExpressionObjectFactory expressionObjectFactory = null;
private IStandardConversionService conversionService = null;
static {
/*
* If this is a WebFlux application, we will use a special mechanism in ThymeleafReactiveView that allows
* the configuration of an execution attribute with a name with a certain prefix and type
* Function>, so that such function is called during View preparation and
* its result (Publisher) is put into the model so that Spring WebFlux asynchronously resolves it (without
* blocking) before asking the View to actually render.
*
* This way, by means of this execution attribute we will set the Mono returned by
* ServerWebExchange into the model and have Spring resolve it non-blockingly into the WebSession object we
* could need during template execution.
*
* NOTE that, per the definition of WebSession in Spring WebFlux, even if this operation does mean the creation
* of a WebSession instance, it does not mean the creation of a real (persisted) user session, cookie emission,
* etc. unless anything is actually put afterwards into the session or it is explicitly started.
*/
if (!SpringVersionUtils.isSpringWebFluxPresent()) {
REACTIVE_MODEL_ADDITIONS_EXECUTION_ATTRIBUTES = Collections.emptyMap();
} else {
// Returns Mono, but we will specify Object in order not to bind this class to Mono at compile time
final Function webSessionInitializer = (exchange) -> exchange.getSession();
REACTIVE_MODEL_ADDITIONS_EXECUTION_ATTRIBUTES =
Collections.singletonMap(WEB_SESSION_EXECUTION_ATTRIBUTE_NAME, webSessionInitializer);
}
}
public SpringStandardDialect() {
super(NAME, PREFIX, PROCESSOR_PRECEDENCE);
}
/**
*
* Returns whether the SpringEL compiler should be enabled in SpringEL expressions or not.
*
*
* Expression compilation can significantly improve the performance of Spring EL expressions, but
* might not be adequate for every environment. Read
* the
* official Spring documentation for more detail.
*
*
* Also note that although Spring includes a SpEL compiler since Spring 4.1, most expressions
* in Thymeleaf templates will only be able to properly benefit from this compilation step when at least
* Spring Framework version 4.2.4 is used.
*
*
* This flag is set to {@code false} by default.
*
*
* @return {@code true} if SpEL expressions should be compiled if possible, {@code false} if not.
*/
public boolean getEnableSpringELCompiler() {
return enableSpringELCompiler;
}
/**
*
* Sets whether the SpringEL compiler should be enabled in SpringEL expressions or not.
*
*
* Expression compilation can significantly improve the performance of Spring EL expressions, but
* might not be adequate for every environment. Read
* the
* official Spring documentation for more detail.
*
*
* Also note that although Spring includes a SpEL compiler since Spring 4.1, most expressions
* in Thymeleaf templates will only be able to properly benefit from this compilation step when at least
* Spring Framework version 4.2.4 is used.
*
*
* This flag is set to {@code false} by default.
*
*
* @param enableSpringELCompiler {@code true} if SpEL expressions should be compiled if possible, {@code false} if not.
*/
public void setEnableSpringELCompiler(final boolean enableSpringELCompiler) {
this.enableSpringELCompiler = enableSpringELCompiler;
}
/**
*
* Returns whether the {@code } marker tags rendered to signal the presence
* of checkboxes in forms when unchecked should be rendered before the checkbox tag itself,
* or after (default).
*
*
* A number of CSS frameworks and style guides assume that the {@code
*
* Note this hidden field is introduced in order to signal the existence of the field in the form being sent,
* even if the checkbox is unchecked (no URL parameter is added for unchecked check boxes).
*
*
* This flag is set to {@code false} by default.
*
*
* @return {@code true} if hidden markers should be rendered before the checkboxes, {@code false} if not.
*
* @since 3.0.10
*/
public boolean getRenderHiddenMarkersBeforeCheckboxes() {
return renderHiddenMarkersBeforeCheckboxes;
}
/**
*
* Sets whether the {@code } marker tags rendered to signal the presence
* of checkboxes in forms when unchecked should be rendered before the checkbox tag itself,
* or after (default).
*
*
* A number of CSS frameworks and style guides assume that the {@code
*
* Note this hidden field is introduced in order to signal the existence of the field in the form being sent,
* even if the checkbox is unchecked (no URL parameter is added for unchecked check boxes).
*
*
* This flag is set to {@code false} by default.
*
*
* @param renderHiddenMarkersBeforeCheckboxes {@code true} if hidden markers should be rendered
* before the checkboxes, {@code false} if not.
*
* @since 3.0.10
*/
public void setRenderHiddenMarkersBeforeCheckboxes(final boolean renderHiddenMarkersBeforeCheckboxes) {
this.renderHiddenMarkersBeforeCheckboxes = renderHiddenMarkersBeforeCheckboxes;
}
@Override
public IStandardVariableExpressionEvaluator getVariableExpressionEvaluator() {
return SPELVariableExpressionEvaluator.INSTANCE;
}
@Override
public IStandardConversionService getConversionService() {
if (this.conversionService == null) {
this.conversionService = new SpringStandardConversionService();
}
return this.conversionService;
}
@Override
public IExpressionObjectFactory getExpressionObjectFactory() {
if (this.expressionObjectFactory == null) {
this.expressionObjectFactory = new SpringStandardExpressionObjectFactory();
}
return this.expressionObjectFactory;
}
@Override
public Set getProcessors(final String dialectPrefix) {
return createSpringStandardProcessorsSet(dialectPrefix, this.renderHiddenMarkersBeforeCheckboxes);
}
@Override
public Map getExecutionAttributes() {
final Map executionAttributes = super.getExecutionAttributes();
executionAttributes.putAll(REACTIVE_MODEL_ADDITIONS_EXECUTION_ATTRIBUTES);
executionAttributes.put(
SpringStandardExpressions.ENABLE_SPRING_EL_COMPILER_ATTRIBUTE_NAME, Boolean.valueOf(getEnableSpringELCompiler()));
return executionAttributes;
}
/**
*
* Create a the set of SpringStandard processors, all of them freshly instanced.
*
*
* @param dialectPrefix the prefix established for the Standard Dialect, needed for initialization
* @return the set of SpringStandard processors.
*/
public static Set createSpringStandardProcessorsSet(final String dialectPrefix) {
return createSpringStandardProcessorsSet(dialectPrefix, DEFAULT_RENDER_HIDDEN_MARKERS_BEFORE_CHECKBOXES);
}
/**
*
* Create a the set of SpringStandard processors, all of them freshly instanced.
*
*
* @param dialectPrefix the prefix established for the Standard Dialect, needed for initialization
* @param renderHiddenMarkersBeforeCheckboxes {@code true} if hidden markers should be rendered
* before the checkboxes, {@code false} if not.
*
* @return the set of SpringStandard processors.
*
* @since 3.0.10
*/
public static Set createSpringStandardProcessorsSet(
final String dialectPrefix, final boolean renderHiddenMarkersBeforeCheckboxes) {
/*
* It is important that we create new instances here because, if there are
* several dialects in the TemplateEngine that extend StandardDialect, they should
* not be returning the exact same instances for their processors in order
* to allow specific instances to be directly linked with their owner dialect.
*/
final Set standardProcessors = StandardDialect.createStandardProcessorsSet(dialectPrefix);
final Set processors = new LinkedHashSet(40);
/*
* REMOVE STANDARD PROCESSORS THAT WE WILL REPLACE
*/
for (final IProcessor standardProcessor : standardProcessors) {
// There are several processors we need to remove from the Standard Dialect set
if (!(standardProcessor instanceof StandardObjectTagProcessor) &&
!(standardProcessor instanceof StandardActionTagProcessor) &&
!(standardProcessor instanceof StandardHrefTagProcessor) &&
!(standardProcessor instanceof StandardMethodTagProcessor) &&
!(standardProcessor instanceof StandardSrcTagProcessor) &&
!(standardProcessor instanceof StandardValueTagProcessor)) {
processors.add(standardProcessor);
} else if (standardProcessor.getTemplateMode() != TemplateMode.HTML) {
// We only want to remove from the StandardDialect the HTML versions of the attribute processors
processors.add(standardProcessor);
}
}
/*
* ATTRIBUTE TAG PROCESSORS
*/
processors.add(new SpringActionTagProcessor(dialectPrefix));
processors.add(new SpringHrefTagProcessor(dialectPrefix));
processors.add(new SpringMethodTagProcessor(dialectPrefix));
processors.add(new SpringSrcTagProcessor(dialectPrefix));
processors.add(new SpringValueTagProcessor(dialectPrefix));
processors.add(new SpringObjectTagProcessor(dialectPrefix));
processors.add(new SpringErrorsTagProcessor(dialectPrefix));
processors.add(new SpringUErrorsTagProcessor(dialectPrefix));
processors.add(new SpringInputGeneralFieldTagProcessor(dialectPrefix));
processors.add(new SpringInputPasswordFieldTagProcessor(dialectPrefix));
processors.add(new SpringInputCheckboxFieldTagProcessor(dialectPrefix, renderHiddenMarkersBeforeCheckboxes));
processors.add(new SpringInputRadioFieldTagProcessor(dialectPrefix));
processors.add(new SpringInputFileFieldTagProcessor(dialectPrefix));
processors.add(new SpringSelectFieldTagProcessor(dialectPrefix));
processors.add(new SpringOptionInSelectFieldTagProcessor(dialectPrefix));
processors.add(new SpringOptionFieldTagProcessor(dialectPrefix));
processors.add(new SpringTextareaFieldTagProcessor(dialectPrefix));
processors.add(new SpringErrorClassTagProcessor(dialectPrefix));
return processors;
}
}