UITableView row animation duration and completion callback

Just came across this. Here's how to do it:

Objective-C

[CATransaction begin];[tableView beginUpdates];[CATransaction setCompletionBlock: ^{    // Code to be executed upon completion}];[tableView insertRowsAtIndexPaths: indexPaths                 withRowAnimation: UITableViewRowAnimationAutomatic];[tableView endUpdates];[CATransaction commit];

Swift

CATransaction.begin()tableView.beginUpdates()CATransaction.setCompletionBlock {    // Code to be executed upon completion}tableView.insertRowsAtIndexPaths(indexArray, withRowAnimation: .Top)tableView.endUpdates()CATransaction.commit()

Expanding on karwag's fine answer, note that on iOS 7, surrounding the CATransaction with a UIView Animation offers control of the table animation duration.

[UIView beginAnimations:@"myAnimationId" context:nil];[UIView setAnimationDuration:10.0]; // Set duration here[CATransaction begin];[CATransaction setCompletionBlock:^{    NSLog(@"Complete!");}];[myTable beginUpdates];// my table changes[myTable endUpdates];[CATransaction commit];[UIView commitAnimations];

The UIView animation's duration has no effect on iOS 6. Perhaps iOS 7 table animations are implemented differently, at the UIView level.

That's one hell of a useful trick!I wrote a UITableView extension to avoid writing CATransaction stuff all the time.

import UIKitextension UITableView {    /// Perform a series of method calls that insert, delete, or select rows and sections of the table view.    /// This is equivalent to a beginUpdates() / endUpdates() sequence,     /// with a completion closure when the animation is finished.    /// Parameter update: the update operation to perform on the tableView.    /// Parameter completion: the completion closure to be executed when the animation is completed.       func performUpdate(_ update: ()->Void, completion: (()->Void)?) {            CATransaction.begin()        CATransaction.setCompletionBlock(completion)        // Table View update on row / section        beginUpdates()        update()        endUpdates()            CATransaction.commit()    }}

This is used like so:

// Insert in the tableView the section we just added in sectionsself.tableView.performUpdate({    self.tableView.insertSections([newSectionIndex], with: UITableViewRowAnimation.top)}, completion: {    // Scroll to next section    let nextSectionIndexPath = IndexPath(row: 0, section: newSectionIndex)    self.tableView.scrollToRow(at: nextSectionIndexPath, at: .top, animated: true)})