old_trunk/schema-registries/src/main/java/org/apache/directory/server/schema/registries/SchemaLoader.java

/*
 *  Licensed to the Apache Software Foundation (ASF) under one
 *  or more contributor license agreements.  See the NOTICE file
 *  distributed with this work for additional information
 *  regarding copyright ownership.  The ASF licenses this file
 *  to you 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.apache.directory.server.schema.registries;


import java.util.Collection;
import java.util.Properties;

import javax.naming.NamingException;

import org.apache.directory.server.schema.bootstrap.Schema;


/**
 * Loads schemas into registres.
 *
 * @author <a href="mailto:dev@directory.apache.org">Apache Directory Project</a>
 * @version $Rev$
 */
public interface SchemaLoader
{
    /**
     * Sets listener used to notify of newly loaded schemas.
     * 
     * @param listener the listener to notify (only one is enough for us)
     * @note probably should have used the observer pattern here 
     */
    public void setListener( SchemaLoaderListener listener );
    
    /**
     * Gets a schema object based on it's name.
     * 
     * @param schemaName the name of the schema to load
     * @return the Schema object associated with the name
     * @throws NamingException if any problems while trying to find the associated Schema
     */
    Schema getSchema( String schemaName ) throws NamingException;
    
    /**
     * Gets a schema object based on it's name and some properties.
     * 
     * @param schemaName the name of the schema to load
     * @param schemaProperties the properties associated with that schema to facilitate locating/loading it
     * @return the Schema object associated with the name
     * @throws NamingException if any problems while trying to find the associated Schema
     */
    Schema getSchema( String schemaName, Properties schemaProperties ) throws NamingException;
    
    /**
     * Loads a collection of schemas.  A best effort should be made to load the dependended 
     * schemas that these schemas may rely on even if they are not included in the collection.
     * 
     * @param schemas the collection of schemas to load
     * @param registries the registries to populate with these schemas
     * @throws NamingException if any kind of problems are encountered during the load
     */
    void loadWithDependencies( Collection<Schema> schemas, Registries registries ) throws NamingException;
    
    /**
     * Loads a single schema at least and possibly it's dependencies.  
     * 
     * @param schemas the schema to load
     * @param registries the registries to populate with these schemas
     * @throws NamingException if any kind of problems are encountered during the load
     */
    void loadWithDependencies( Schema schemas, Registries registries ) throws NamingException;
    
    /**
     * Loads a single schema.  Do not try to resolve dependencies while implementing this method.
     * 
     * @param schema the schema to load
     * @param registries the registries to populate with these schemas
     * @param isDepLoad tells the loader if this load request is to satisfy a dependency
     * @throws NamingException if any kind of problems are encountered during the load
     */
    void load( Schema schema, Registries registries, boolean isDepLoad ) throws NamingException;
}