AutoSizeTableViewCell.h

//
//  AutoSizeTableViewCell.h
//  OCVeryTemp
//
//  Created by Don Mag on 2/19/18.
//

#import <UIKit/UIKit.h>

@interface AutoSizeTableViewCell : UITableViewCell

@property IBOutlet UILabel *topLabel;
@property IBOutlet UILabel *botLabel;

@end

AutoSizeTableViewCell.m

//
//  AutoSizeTableViewCell.m
//  OCVeryTemp
//
//  Created by Don Mag on 2/19/18.
//

#import "AutoSizeTableViewCell.h"

@implementation AutoSizeTableViewCell

@end

WithAlertTableViewController.h

//
//  WithAlertTableViewController.h
//  OCVeryTemp
//
//  Created by Don Mag on 2/19/18.
//

#import <UIKit/UIKit.h>

@interface WithAlertTableViewController : UITableViewController

@end

WithAlertTableViewController.m

//
//  WithAlertTableViewController.m
//  OCVeryTemp
//
//  Created by Don Mag on 2/19/18.
//

#import "WithAlertTableViewController.h"
#import "AutoSizeTableViewCell.h"

@interface WithAlertTableViewController ()

@property NSMutableArray *theData;

@end

@implementation WithAlertTableViewController

- (void)viewDidLoad {
	[super viewDidLoad];
	
	// init data array with single-letter strings
	_theData = [NSMutableArray array];
	NSString *str = @"ABCDEFGHIJKLMNOPQRSTUVWXYZ";
	for (int i = 0; i < [str length]; i++) {
		NSString *ch = [str substringWithRange:NSMakeRange(i, 1)];
		[_theData addObject:ch];
	}
	
	self.tableView.rowHeight = UITableViewAutomaticDimension;
	self.tableView.estimatedRowHeight = 80.0;
	
}

#pragma mark - Table view data source

- (NSInteger)numberOfSectionsInTableView:(UITableView *)tableView {
	return 1;
}

- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section {
	return [_theData count];
}

- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath {
	AutoSizeTableViewCell *cell = (AutoSizeTableViewCell *)[tableView dequeueReusableCellWithIdentifier:@"AutoCell" forIndexPath:indexPath];
	
	cell.topLabel.text = [NSString stringWithFormat:@"Row: %ld - %@", (long)indexPath.row, _theData[indexPath.row]];
	
	// set bottom label to 1, 2 or 3 lines of text
	NSString *bottomText = @"Bottom label text";
	for (int i = 0; i < indexPath.row % 3; i++) {
		bottomText = [NSString stringWithFormat:@"%@\nLine %ld", bottomText, (long)i];
	}
	cell.botLabel.text = bottomText;
	
	return cell;
}

- (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath
{
	NSString *title = @"This is the title";
	UIAlertController *alertController = [UIAlertController alertControllerWithTitle:title message:nil preferredStyle:UIAlertControllerStyleAlert];
	
	// add a line of text to the data for the selected row
	_theData[indexPath.row] = [NSString stringWithFormat:@"%@\n%@", _theData[indexPath.row], @"Added Line of text"];
	
	// save
	[alertController addAction:[UIAlertAction actionWithTitle:@"Save" style:UIAlertActionStyleDefault handler:^(UIAlertAction * _Nonnull action) {
		// this causes a scroll jump when called in this block 
		// (but I don't see a "jump" in this test)
		[tableView reloadRowsAtIndexPaths:@[indexPath] withRowAnimation:UITableViewRowAnimationFade];
	}]];
	
	// cancel
	[alertController addAction:[UIAlertAction actionWithTitle:@"Cancel" style:UIAlertActionStyleCancel handler:nil]];
	
	[self presentViewController:alertController animated:YES completion:nil];
}

@end