org.elasticsearch.common.inject.spi.Element Maven / Gradle / Ivy
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/*
* Copyright (C) 2008 Google Inc.
*
* 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.elasticsearch.common.inject.spi;
import org.elasticsearch.common.inject.Binder;
/**
* A core component of a module or injector.
*
* The elements of a module can be inspected, validated and rewritten. Use {@link
* Elements#getElements(org.elasticsearch.common.inject.Module[]) Elements.getElements()} to read the elements
* from a module, and {@link Elements#getModule(Iterable) Elements.getModule()} to rewrite them.
* This can be used for static analysis and generation of Guice modules.
*
* @author [email protected] (Jesse Wilson)
* @author [email protected] (Bob Lee)
* @since 2.0
*/
public interface Element {
/**
* Returns an arbitrary object containing information about the "place" where this element was
* configured. Used by Guice in the production of descriptive error messages.
*
* Tools might specially handle types they know about; {@code StackTraceElement} is a good
* example. Tools should simply call {@code toString()} on the source object if the type is
* unfamiliar.
*/
Object getSource();
/**
* Accepts an element visitor. Invokes the visitor method specific to this element's type.
*
* @param visitor to call back on
*/
T acceptVisitor(ElementVisitor visitor);
/**
* Writes this module element to the given binder (optional operation).
*
* @param binder to apply configuration element to
* @throws UnsupportedOperationException if the {@code applyTo} method is not supported by this
* element.
*/
void applyTo(Binder binder);
}