Resize tableView footer view

resizeTableViewFooter.m

//update footer view's frame
-(void)updateFrame
{
    CGSize newSize = [self systemLayoutSizeFittingSize: CGSizeMake(CGRectGetWidth(self.frame), CGFLOAT_MAX)];
    CGRect newFrame = self.frame;
    newFrame.size = newSize;
    self.frame = newFrame;
}

//when updating footer, need to call tableFooterView's setter in tableView to invoke resetting the tableview's contentView bounds 

[UIView animateWithDuration: 0.3 animations:^{
        [self updateFrame];
        self.parentTableView.tableFooterView = self; // has to call tableFooterView setter to update tableview's contentview bounds
}];