How to create a very simple UITableView programmatically with dynamic cell height and auto-layout?

Question

Please note: I know that there are quite a few examples of such lines. I am looking for the most basic solution with minimal setup.

I tried to create it myself, and I know that I'm leaving.

#import "ViewController.h" @interface ViewController () <UITableViewDataSource, UITableViewDelegate> @property(strong, nonatomic) UITableView *tableView; @property(strong, nonatomic) NSMutableArray *dataArray; @property (strong, nonatomic) UITableViewCell *customCell; @end @implementation ViewController - (void)viewDidLoad { [super viewDidLoad]; // Do any additional setup after loading the view, typically from a nib. self.tableView = [[UITableView alloc] initWithFrame:CGRectMake(0, 0, self.view.frame.size.width, self.view.frame.size.height) style:UITableViewStylePlain]; [self.tableView setDataSource:self]; [self.tableView setDelegate:self]; [self.tableView setShowsVerticalScrollIndicator:NO]; self.tableView.translatesAutoresizingMaskIntoConstraints = NO; self.tableView.rowHeight = UITableViewAutomaticDimension; [self.view addSubview:self.tableView]; self.dataArray = [@[@"For the past 33 years, I have looked in the mirror every morning and asked myself: 'If today were the last day of my life, would I want to do what I am about to do today?' And whenever the answer has been 'No' for too many days in a row, I know I need to change something. -Steve Jobs", @"Be a yardstick of quality. Some people aren't used to an environment where excellence is expected. - Steve Jobs", @"Innovation distinguishes between a leader and a follower. -Steve Jobs"] mutableCopy]; } - (void)didReceiveMemoryWarning { [super didReceiveMemoryWarning]; // Dispose of any resources that can be recreated. } - (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section { return [self.dataArray count]; } - (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath { NSString *cellIdentifier = @"CustomCell"; UITableViewCell *cell = (UITableViewCell *)[tableView dequeueReusableCellWithIdentifier:cellIdentifier]; if (cell == nil) { cell = [[UITableViewCell alloc] initWithStyle:UITableViewCellStyleDefault reuseIdentifier:cellIdentifier]; } cell.backgroundColor = [UIColor colorWithRed:249.0/255 green:237.0/255 blue:224.0/255 alpha:1.0]; int dataIndex = (int) indexPath.row % [self.dataArray count]; cell.textLabel.text = self.dataArray[dataIndex]; cell.textLabel.numberOfLines = 0; cell.textLabel.lineBreakMode = NSLineBreakByWordWrapping; NSDictionary *views = @{@"label":cell.textLabel}; NSArray *constraints = [NSLayoutConstraint constraintsWithVisualFormat:@"H:|[label]|" options:0 metrics:nil views:views]; [cell.contentView addConstraints:constraints]; constraints = [NSLayoutConstraint constraintsWithVisualFormat:@"V:|[label]|" options: 0 metrics:nil views:views]; [cell.contentView addConstraints:constraints]; return cell; } - (CGFloat)tableView:(UITableView *)tableView heightForRowAtIndexPath:(NSIndexPath *)indexPath { // Calculate a height based on a cell if(!self.customCell) { self.customCell = [self.tableView dequeueReusableCellWithIdentifier:@"CustomCell"]; } // Configure the cell int dataIndex = (int) indexPath.row % [self.dataArray count]; self.customCell.textLabel.text = self.dataArray[dataIndex]; // auto layout NSDictionary *views = @{@"label":self.customCell.textLabel}; NSArray *constraints = [NSLayoutConstraint constraintsWithVisualFormat:@"H:|[label]|" options:0 metrics:nil views:views]; [self.customCell.contentView addConstraints:constraints]; constraints = [NSLayoutConstraint constraintsWithVisualFormat:@"V:|[label]|" options: 0 metrics:nil views:views]; [self.customCell.contentView addConstraints:constraints]; // Layout the cell [self.customCell layoutIfNeeded]; // Get the height for the cell CGFloat height = [self.customCell.contentView systemLayoutSizeFittingSize:UILayoutFittingCompressedSize].height; // Padding of 1 point (cell separator) CGFloat separatorHeight = 1; return height + separatorHeight; } - (CGFloat)tableView:(UITableView *)tableView estimatedHeightForRowAtIndexPath:(NSIndexPath *)indexPath { return 140; } @end 

Answer 1

So, after going through many examples, I finally realized what happened. Its one of those things where some missing lines ruined the whole code. For me it was

 cell.bodyLabel.preferredMaxLayoutWidth = tableView.bounds.size.width; 

which we need to add to the method heightForRowAtIndexPath or it gives a constraint error.

I got the solution thanks to one of the comments on the amazing answer here . Although in the sample code provided in the answer, the line above is given in the cellForRowAtIndexPath function instead of heightForRowAtIndexPath. But my code could not work that way.

So, the base code:

//RJCell.h

 #import <UIKit/UIKit.h> @interface RJTableViewCell : UITableViewCell @property (strong, nonatomic) UILabel *titleLabel; @property (strong, nonatomic) UILabel *bodyLabel; @end 

//RJCell.m

 #import "RJTableViewCell.h" @interface RJTableViewCell () @property (nonatomic, assign) BOOL didSetupConstraints; @end @implementation RJTableViewCell - (id)initWithStyle:(UITableViewCellStyle)style reuseIdentifier:(NSString *)reuseIdentifier { self = [super initWithStyle:style reuseIdentifier:reuseIdentifier]; if (self) { // Initialization code self.titleLabel = [[UILabel alloc] init]; [self.titleLabel setTranslatesAutoresizingMaskIntoConstraints:NO]; [self.titleLabel setLineBreakMode:NSLineBreakByTruncatingTail]; [self.titleLabel setNumberOfLines:1]; [self.titleLabel setTextAlignment:NSTextAlignmentLeft]; [self.titleLabel setTextColor:[UIColor blackColor]]; [self.titleLabel setBackgroundColor:[UIColor clearColor]]; [self.contentView addSubview:self.titleLabel]; // Add this label to the button self.bodyLabel = [[UILabel alloc] init]; [self.bodyLabel setTranslatesAutoresizingMaskIntoConstraints:NO]; [self.bodyLabel setContentCompressionResistancePriority:UILayoutPriorityRequired forAxis:UILayoutConstraintAxisVertical]; [self.bodyLabel setLineBreakMode:NSLineBreakByTruncatingTail]; [self.bodyLabel setNumberOfLines:0]; [self.bodyLabel setTextAlignment:NSTextAlignmentLeft]; [self.bodyLabel setTextColor:[UIColor darkGrayColor]]; [self.bodyLabel setBackgroundColor:[UIColor clearColor]]; [self.contentView addSubview:self.bodyLabel]; } return self; } - (void)updateConstraints { [super updateConstraints]; if (self.didSetupConstraints) return; // Get the views dictionary NSDictionary *viewsDictionary = @{ @"titleLabel" : self.titleLabel, @"bodyLabel" : self.bodyLabel }; NSString *format; NSArray *constraintsArray; //Create the constraints using the visual language format format = @"V:|-10-[titleLabel]-10-[bodyLabel]-10-|"; constraintsArray = [NSLayoutConstraint constraintsWithVisualFormat:format options:0 metrics:nil views:viewsDictionary]; [self.contentView addConstraints:constraintsArray]; format = @"|-10-[titleLabel]-10-|"; constraintsArray = [NSLayoutConstraint constraintsWithVisualFormat:format options:0 metrics:nil views:viewsDictionary]; [self.contentView addConstraints:constraintsArray]; format = @"|-10-[bodyLabel]-10-|"; constraintsArray = [NSLayoutConstraint constraintsWithVisualFormat:format options:0 metrics:nil views:viewsDictionary]; [self.contentView addConstraints:constraintsArray]; self.didSetupConstraints = YES; } @end 

//RJTableViewController.h

 #import <UIKit/UIKit.h> @interface RJTableViewController : UITableViewController @end 

//RJTableViewController.m

 #import "RJTableViewController.h" #import "RJTableViewCell.h" static NSString *CellIdentifier = @"CellIdentifier"; @interface RJTableViewController () @property(strong,nonatomic) NSMutableArray *titleArray; @property(strong,nonatomic) NSMutableArray *bodyArray; @end @implementation RJTableViewController - (id)initWithStyle:(UITableViewStyle)style { self = [super initWithStyle:style]; if (self) { // Custom initialization self.title = @"Table View Controller"; } return self; } - (void)viewDidLoad { [super viewDidLoad]; [self.tableView registerClass:[RJTableViewCell class] forCellReuseIdentifier:CellIdentifier]; self.titleArray = [[UIFont familyNames] mutableCopy]; for(int i = 0; i < 100; i++) { [self.titleArray addObjectsFromArray:[UIFont familyNames]]; } self.bodyArray = [@[@"Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua.",@"Ut enim ad minim veniam, quis nostrud exercitation ullamco laboris nisi ut aliquip ex ea commodo consequat.Ut enim ad minim veniam, quis nostrud exercitation ullamco laboris nisi ut aliquip ex ea commodo consequat.Ut enim ad minim veniam, quis nostrud exercitation ullamco laboris nisi ut aliquip ex ea commodo consequat.Ut enim ad minim veniam, quis nostrud exercitation ullamco laboris nisi ut aliquip ex ea commodo consequat.Ut enim ad minim veniam, quis nostrud exercitation ullamco laboris nisi ut aliquip ex ea commodo consequat.Ut enim ad minim veniam, quis nostrud exercitation ullamco laboris nisi ut aliquip ex ea commodo consequat.",@"Duis aute irure dolor in reprehenderit in voluptate velit esse cillum dolore eu fugiat nulla pariatur.",@"Excepteur sint occaecat cupidatat non proident, sunt in culpa qui officia deserunt mollit anim id est laborum."] mutableCopy]; } - (void)contentSizeCategoryChanged:(NSNotification *)notification { [self.tableView reloadData]; } #pragma mark - Table view data source - (NSInteger)numberOfSectionsInTableView:(UITableView *)tableView { // Return the number of sections. return 1; } - (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section { // Return the number of rows in the section. return [self.titleArray count]; } - (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath { RJTableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:CellIdentifier forIndexPath:indexPath]; int dataIndex = (int) indexPath.row % [self.bodyArray count]; cell.titleLabel.text = self.titleArray[indexPath.row]; cell.bodyLabel.text = self.bodyArray[dataIndex]; // Make sure the constraints have been added to this cell, since it may have just been created from scratch [cell setNeedsUpdateConstraints]; return cell; } - (CGFloat)tableView:(UITableView *)tableView heightForRowAtIndexPath:(NSIndexPath *)indexPath { RJTableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:CellIdentifier]; int dataIndex = (int) indexPath.row % [self.bodyArray count]; cell.titleLabel.text = self.titleArray[indexPath.row]; cell.bodyLabel.text = self.bodyArray[dataIndex]; cell.bodyLabel.preferredMaxLayoutWidth = tableView.bounds.size.width - (20.0 * 2.0f); [cell setNeedsUpdateConstraints]; [cell updateConstraintsIfNeeded]; [cell.contentView setNeedsLayout]; [cell.contentView layoutIfNeeded]; CGFloat height = [cell.contentView systemLayoutSizeFittingSize:UILayoutFittingCompressedSize].height; return height; } - (CGFloat)tableView:(UITableView *)tableView estimatedHeightForRowAtIndexPath:(NSIndexPath *)indexPath { return 200.0f; } @end 

Basically, the hard part is in two places, setting limits first. Secondly, the implementation of the methods heightForRowAtIndexPath and cellForRowAtIndexPath.