public Object[] getChildren(Object o) {
logger.debug("get children: " + o);
if(o instanceof CampaignView) {
CampaignDao campaignDao = (CampaignDao)ServiceUtils.getService(Activator.getDefault().getBundle().getBundleContext(), CampaignDao.class.getName());
logger.trace("campaignDao: " + campaignDao);
if(campaignDao != null) {
try {
Set<Campaign> campaigns = campaignDao.getCampaigns();
for(Campaign c : campaigns) {
logger.debug("registering as a listener to campaign: " + c);
c.addPropertyChangeListener((CampaignView)o);
}