/*
* Copyright (c) 2010 Lockheed Martin Corporation
*
* 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.eurekastreams.server.action.execution.profile;
import org.apache.commons.logging.Log;
import org.eurekastreams.commons.actions.ExecutionStrategy;
import org.eurekastreams.commons.actions.context.PrincipalActionContext;
import org.eurekastreams.commons.logging.LogFactory;
import org.eurekastreams.server.action.request.profile.GetFollowersFollowingRequest;
import org.eurekastreams.server.domain.EntityType;
import org.eurekastreams.server.domain.PagedSet;
import org.eurekastreams.server.domain.Person;
import org.eurekastreams.server.persistence.DomainGroupMapper;
import org.eurekastreams.server.persistence.FollowMapper;
import org.eurekastreams.server.persistence.PersonMapper;
/**
* Action to get the followers of a person or group or the people or groups followed by a person.
*
*/
public class GetFollowersExecution implements ExecutionStrategy<PrincipalActionContext>
{
/**
* Logger.
*/
private Log log = LogFactory.make();
/**
* PersonMapper used to retrieve person from the db.
*/
private PersonMapper personMapper = null;
/**
* GroupMapper used to retrieve person from the db.
*/
private DomainGroupMapper groupMapper = null;
/**
* Constructor that sets up the mapper.
*
* @param inPersonMapper
* - instance of PersonMapper
* @param inGroupMapper
* - instance of DomainGroupMapper
*/
public GetFollowersExecution(final PersonMapper inPersonMapper, final DomainGroupMapper inGroupMapper)
{
personMapper = inPersonMapper;
groupMapper = inGroupMapper;
}
/**
* Returns true or false if the group exists and the current user is a coordinator.
*
* @param inActionContext
* The action context.
* @return true if the group exists and the user is authorized, false otherwise
*/
@Override
public PagedSet<Person> execute(final PrincipalActionContext inActionContext)
{
// get the request
GetFollowersFollowingRequest inRequest = (GetFollowersFollowingRequest) inActionContext.getParams();
// get the unique entity Id
final String uniqueEntityId = inRequest.getEntityId();
// get the entity type.
EntityType targetType = inRequest.getEntityType();
// get the start value.
Integer startValue = (inRequest.getStartIndex()).intValue();
// get the end value.
Integer endValue = (inRequest.getEndIndex()).intValue();
// given the entity type, get the follow mapper.
FollowMapper mapper = pickMapper(targetType);
PagedSet<Person> connections = mapper.getFollowers(uniqueEntityId, startValue, endValue);
if (log.isTraceEnabled())
{
log.trace("Retrieved " + connections.getFromIndex() + " to " + connections.getToIndex() + " of "
+ connections.getTotal() + " followers");
}
return connections;
}
/**
* Pick a mapper based on the type of the target.
*
* @param targetType
* the target type
* @return the selected mapper
*/
private FollowMapper pickMapper(final EntityType targetType)
{
if (EntityType.PERSON == targetType)
{
return personMapper;
}
if (EntityType.GROUP == targetType)
{
return groupMapper;
}
throw new IllegalArgumentException("GetFollowersAction supports Person and DomainGroup targets only");
}
}