gistfile1.txt

PostTableItem *pitem = [PostTableItem itemWithPost:post
                                                    dataSource:self
                                                      expanded:expanded 
                                                     withBlock:nil];
pitem.urlBlock =  ^{ 
    [self.controller expandCellWithPost:post type:!expanded];               
};


SECOND WAY:

pitem.urlBlock =  ^{ 
     pitem.isExpanded = !pitem.isExpanded;
     [self.controller expandCellWithPost:pitem.post type:pitem.expanded];               
};