Creating self-sizing table view cells

At a glance

Project structure

SelfSizingCellsWithDynamicType/
├── AppDelegate.swift
├── ViewController.swift
├── CustomDataSource.swift
├── CustomCell.swift
├── Base.lproj/Main.storyboard
└── Localizable.stringsdict

Structure observations

• Controller wiring, row data, and cell layout are separate roles.
• CustomCell.swift is the feature core; AppDelegate explicitly says it is not central to the sample.
• Localization data is separate from the data source that formats the pluralized headline.

Overall architecture

flowchart LR
    Storyboard["Main.storyboard"] --> Controller["ViewController"]
    Controller -->|"strong private owner"| DataSource["CustomDataSource"]
    Controller -->|"weak outlet"| Table["UITableView"]
    Table -->|"weak dataSource callback"| DataSource
    DataSource -->|"register / dequeue / configure"| Cell["CustomCell"]
    Cell --> Headline["headlineLabel"]
    Cell --> Body["bodyLabel"]
    Dynamic["Content-size category"] --> Cell
    Cell -->|"intrinsic sizes + constraints"| Height["Self-sized row height"]

Reference code

SelfSizingCellsWithDynamicType/ViewController.swift:16 — the controller keeps the data source alive, lets it register its own cell type, and then assigns it to the table.

@IBOutlet weak var tableView: UITableView!

private let dataSource = CustomDataSource()

override func viewDidLoad() {
    super.viewDidLoad()

    dataSource.registerCells(with: tableView)
    tableView.dataSource = dataSource
}

Interpretation

ViewController is only a composition boundary. Row knowledge stays in CustomDataSource, and all sizing knowledge stays in CustomCell; UIKit calculates height from label intrinsic content sizes and the cell’s complete vertical constraints.

Ownership and state

classDiagram
    ViewController o-- UITableView : weak IBOutlet
    ViewController *-- CustomDataSource : private let
    UITableView --> CustomDataSource : weak callback reference
    CustomDataSource *-- SampleTupleArray : immutable sampleData
    UITableView *-- CustomCell : reuse lifecycle
    CustomCell *-- UILabel : headlineLabel
    CustomCell *-- UILabel : bodyLabel
    CustomCell *-- NSLayoutConstraint : active layout graph

Ownership evidence

SelfSizingCellsWithDynamicType/CustomCell.swift:29 — the cell creates and retains both labels, and both initializer paths run one private setup routine.

let headlineLabel = makeSampleLabel()
let bodyLabel = makeSampleLabel()

override init(
    style: UITableViewCell.CellStyle,
    reuseIdentifier: String?
) {
    super.init(style: style, reuseIdentifier: reuseIdentifier)
    setUpLabelsAndConstraints()
}

required init?(coder aDecoder: NSCoder) {
    super.init(coder: aDecoder)
    setUpLabelsAndConstraints()
}

The controller’s strong data-source property matters because UIKit’s dataSource reference is non-owning; a temporary data source would disappear after setup.

Class and protocol design

There is no app-defined protocol. The only callback abstraction is UITableViewDataSource, and the concrete data source is deliberately small.

Access control

Reference code

SelfSizingCellsWithDynamicType/CustomCell.swift:37 — construction mechanics stay private while the resulting labels are exposed read-only for row binding.

private static func makeSampleLabel() -> UILabel {
    let label = UILabel()
    label.translatesAutoresizingMaskIntoConstraints = false
    label.numberOfLines = 0
    return label
}

Logic ownership and placement

Design patterns

Naming conventions

• CustomCell and CustomDataSource use role suffixes, though “Custom” is generic because the sample is narrowly scoped.
• headlineLabel and bodyLabel name semantic typography roles.
• makeSampleLabel is a factory verb; setUpLabelsAndConstraints describes one-time construction.
• reuseIdentifier and registerCells(with:) mirror table-view vocabulary.

Architecture takeaways

• Keep a strong owner for weak UIKit callback properties.
• Let the data source register/configure the cell types it creates.
• Put a complete constraint chain and Dynamic Type configuration inside the reusable cell.
• Expose label references only when direct binding is intentional; otherwise prefer a semantic configure method.
• Self-sizing is an Auto Layout result, not controller-maintained row-height state.

Source map

• Official Apple documentation