freemarker.template.AdapterTemplateModel Maven / Gradle / Ivy
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/*
* Copyright 2014 Attila Szegedi, Daniel Dekany, Jonathan Revusky
*
* 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 freemarker.template;
/**
* A {@link TemplateModel} that can be unwrapped and then it considers a provided desired (hint) class. This is
* useful when multiple languages has to communicate with each other through FreeMarker. For example, if we have a
* model that wraps a Jython object, then we have to unwrap that differently when we pass it to plain Java method and
* when we pass it to a Jython method.
*
* This is rarely implemented by applications. It is typically implemented by the model classes belonging to
* {@link ObjectWrapper}-s.
*/
public interface AdapterTemplateModel extends TemplateModel {
/**
* Retrieves the underlying object, or some other object semantically
* equivalent to its value narrowed by the class hint.
* @param hint the desired class of the returned value. An implementation
* should make reasonable effort to retrieve an object of the requested
* class, but if that is impossible, it must at least return the underlying
* object as-is. As a minimal requirement, an implementation must always
* return the exact underlying object when
* hint.isInstance(underlyingObject) holds. When called
* with java.lang.Object.class, it should return a generic Java
* object (i.e. if the model is wrapping a scripting language object that is
* further wrapping a Java object, the deepest underlying Java object should
* be returned).
* @return the underlying object, or its value accommodated for the hint
* class.
*/
public Object getAdaptedObject(Class hint);
}