/*
* Copyright 2000-2016 Vaadin Ltd.
*
* 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 com.vaadin.server;
/**
* An extension is an entity that is attached to a Component or another
* Extension and independently communicates between client and server.
* <p>
* An extension can only be attached once. It is not supported to move an
* extension from one target to another.
* <p>
* Extensions can use shared state and RPC in the same way as components.
*
* @author Vaadin Ltd
* @since 7.0.0
*/
public interface Extension extends ClientConnector {
/**
* Remove this extension from its target. After an extension has been
* removed, it cannot be attached again.
*/
void remove();
/**
* Sets the parent connector of the connector.
*
* This method automatically calls {@link #attach()} if the connector
* becomes attached to the session.
* <p>
* This method is rarely called directly.
* {@link AbstractClientConnector#addExtension(Extension)} is normally used
* for adding extensions to a parent and it will call this method
* implicitly.
* </p>
*
* @param parent
* the parent connector
* @throws IllegalStateException
* if a parent is given even though the connector already has a
* parent
*/
public void setParent(ClientConnector parent);
}