org.thymeleaf.expression.IExpressionObjectFactory Maven / Gradle / Ivy
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/*
* =============================================================================
*
* 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.expression;
import java.util.Set;
import org.thymeleaf.context.IExpressionContext;
/**
*
* Factory objects for creating {@link IExpressionObjects} instances. These factories are the artifacts
* specified by {@link org.thymeleaf.dialect.IExpressionObjectDialect} implementations, instead of specifying
* the expression objects themselves, so that these expression objects are only created when really needed
* in template expressions.
*
*
* @author Daniel Fernández
* @since 3.0.0
*
*/
public interface IExpressionObjectFactory {
/**
*
* Return the complete list of expression objects that can be created by this factory.
*
*
* This list will be used for determining if a factory might actually be asked to build an object, so
* it should contain all possible objects to be built by the factory.
*
*
* @return the list of objects this factory can build.
*/
public Set getAllExpressionObjectNames();
/**
*
* Build the requested object.
*
*
* @param context the context being used for processing the template.
* @param expressionObjectName the name of the expression object to be built.
* @return the built object, or null if the object could not be built.
*/
public Object buildObject(final IExpressionContext context, final String expressionObjectName);
/**
*
* Returns whether a specific expression object can be cached and reused for all expressions in the
* same template execution or not.
*
*
* Note this cacheable flag refers only to reuse of the object in expressions in expressions
* executed during a single template execution.
*
* @param expressionObjectName the name of the expression object.
* @return true is the object is to be considered cacheable, false if not.
*/
public boolean isCacheable(final String expressionObjectName);
}