/* ====================================================================
* The Jcorporate Apache Style Software License, Version 1.2 05-07-2002
*
* Copyright (c) 1995-2002 Jcorporate Ltd. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
*
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in
* the documentation and/or other materials provided with the
* distribution.
*
* 3. The end-user documentation included with the redistribution,
* if any, must include the following acknowledgment:
* "This product includes software developed by Jcorporate Ltd.
* (http://www.jcorporate.com/)."
* Alternately, this acknowledgment may appear in the software itself,
* if and wherever such third-party acknowledgments normally appear.
*
* 4. "Jcorporate" and product names such as "Expresso" must
* not be used to endorse or promote products derived from this
* software without prior written permission. For written permission,
* please contact info@jcorporate.com.
*
* 5. Products derived from this software may not be called "Expresso",
* or other Jcorporate product names; nor may "Expresso" or other
* Jcorporate product names appear in their name, without prior
* written permission of Jcorporate Ltd.
*
* 6. No product derived from this software may compete in the same
* market space, i.e. framework, without prior written permission
* of Jcorporate Ltd. For written permission, please contact
* partners@jcorporate.com.
*
* THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED
* WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
* DISCLAIMED. IN NO EVENT SHALL JCORPORATE LTD OR ITS CONTRIBUTORS
* BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
* EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED
* TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
* USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
* ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
* OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
* OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
* ====================================================================
*
* This software consists of voluntary contributions made by many
* individuals on behalf of the Jcorporate Ltd. Contributions back
* to the project(s) are encouraged when you make modifications.
* Please send them to support@jcorporate.com. For more information
* on Jcorporate Ltd. and its products, please see
* <http://www.jcorporate.com/>.
*
* Portions of this software are based upon other open source
* products and are subject to their respective licenses.
*/
package com.jcorporate.expresso.kernel;
import com.jcorporate.expresso.kernel.metadata.ComponentMetadata;
import java.util.Iterator;
/**
* An <code>Embedded Component</code> is a component that is (1) Not a container
* and (2) it's metadata is embedded within the metadata of its parent. This
* allows for the guarantee that if one component is installed that it can bring
* its required components with it. An example is PersistenceManager
*
* @author Michael Rimov
* @see com.jcorporate.expresso.core.dataobjects.PersistenceManager
*/
abstract public class EmbeddedComponent implements ExpressoComponent {
/**
* Cached metadata once we've looked it up from the parent
*/
private ComponentMetadata myMetadata = null;
/**
* Parent Container Reference
*/
private Containable myParent = null;
/**
* Default Do Nothing Constructor
*/
public EmbeddedComponent() {
}
/**
* Because we look up our metadata in the parent component, we have to
* somehow know WHAT component's metadata is ours. Sub classes need to
* override this one-liner and return the name of the metadata we're
* looking for.
*
* @return java.lang.String
*/
abstract public String getMetadataName();
/**
* Returns the metadata by retrieving the appropriate metadata from the parent
*
* @return ComponentMetadata for this component.
* @throws IllegalArgumentException if the parent cannot be queried for the
* appropriate metadata
*/
public synchronized ComponentMetadata getMetaData() {
if (myMetadata == null) {
ExpressoComponent ec = (ExpressoComponent) this.getParent();
ComponentMetadata parentMetadata = ec.getMetaData();
for (Iterator i = parentMetadata.getChildren().iterator(); i.hasNext();) {
ComponentMetadata oneChild = (ComponentMetadata) i.next();
if (this.getMetadataName().equals(oneChild.getName())) {
myMetadata = oneChild;
break;
}
}
if (myMetadata == null) {
throw new IllegalArgumentException("Unable to find metadata " +
"in parent corresponding to component named: "
+ this.getMetadataName());
}
}
return myMetadata;
}
/**
* Retrieve the parent component [if any]. May return null.
*
* @return ExpressoComponent or null
*/
public synchronized Containable getParent() {
return myParent;
}
/**
* Called by the parent upon initial Expresso component creation so that the
* child component can find it's container.
*
* @param parent the 'containing' component.
*/
public synchronized void setParent(Containable parent) {
myParent = parent;
}
}
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