View doesn't appear as expected - ios

Question

Theoretically the following code should animate the table view cell of the screen to the right and bring in a dark "view" in it's place.
CGPoint location = [gesture locationInView:tableView];
NSIndexPath *swipedIndexPath = [tableView indexPathForRowAtPoint:location];
UITableViewCell *swipedCell = [tableView cellForRowAtIndexPath:swipedIndexPath];
//code to create view
UIView *sideView;
sideView.backgroundColor = [UIColor lightGrayColor];
//set the side view frame to the same as the cell
sideView.frame = swipedCell.frame;
//add it to the tableview
[tableView addSubview:sideView];
[UIView animateWithDuration:1
animations:^{
sideView.frame = CGRectMake(0, swipedCell.frame.origin.y, swipedCell.frame.size.width, swipedCell.frame.size.height);
// While simultaneously moving the cell's frame offscreen
// The net effect is that the side swipe view is pushing the cell offscreen
swipedCell.frame = CGRectMake(swipedCell.frame.size.width, swipedCell.frame.origin.y, swipedCell.frame.size.width, swipedCell.frame.size.height); //move cell off
}];
However, only the cell moves off the screen. No gray view comes in it's place.
Is there a step I am missing? What is wrong with this code?
Video of example here

Answer 1

The big error is that you're not initializing sideView to anything.
Try UIView* sideview = [[UIView alloc] initWithFrame:swipedCell.frame];

Answer 2

It doesn't sound like a good idea to add a view in place of a cell just like that. You'd have to deal with scrolling, table view editing, and other stuff that the UITableView takes care of for you. So instead, try adding the sideView as a subview of swipedCell.contentView and then doing this animation instead:
[UIView animateWithDuration:1 animations:^{
sideView.frame = CGRectMake(0, swipedCell.frame.origin.y, swipedCell.frame.size.width, swipedCell.frame.size.height);
//This moves all the subviews except for the sideView off the screen
for (UIView *subview in swipedCell.contentView.subviews)
if (![subview isEqual:sideView])
subview.frame = CGRectOffset(subview.frame, swipedCell.frame.size.width, 0.0);
}];
Hope this helps!