Populate

What is Populate?

Often in our iOS apps, we need to populate a UITableView or UICollectionView with some data.

When using CoreData, this is a fairly trivial task since NSFetchedResultsController does most of the heavy lifting for us.

Introducing Populate

Here's a few reason you should start using Populate in your projects now:

• 100% Swift
• Protocol-Oriented architecture
• Type-safety (Views, Cells and Data)
• Supports both value and/or reference types
• Multiple type-safe cells
• ArrayDataProvider -- a type-safe provider similar to NSFetchedResultsController
  • Filtering
  • Sectioning
  • Sorting
  • Add, remove, update (with type-safety)

So lets take a look and see what this looks like in code.

Example

To get started, Populate only requires 2 things:

// Sets up the coordinator
init(dataView: V, cellProvider: DataCoordinatorCellProviding, @noescape dataProvider: () -> D)

// Configure your cells
func dataCoordinator<V: DataView>(dataView: V, cellConfigurationForIndexPath indexPath: NSIndexPath) -> DataCellConfiguration

Lets start by settings up the DataCoordinator:

@import Populate

final class PeopleViewController: UITableViewController, DataCoordinatorCellProviding {

  // Popoulate uses a coordinator to manage your view, its cells and the associated data
  private var dataCoordinator: DataCoordinator<UITableView, ArrayDataProvider<Person>>?

  override func viewDidLoad() {
    super.viewDidLoad()

    // We initialize the coordinator with a dataView, cellProvider and a dataProvider configuration
    dataCoordinator = DataCoordinator(dataView: tableView, cellProvider: self) {

      // So lets seed our dataProvider for convenience
      let provider = ArrayDataProvider(items: [
        Person(name: "Shaps", address: Address(postcode: "W5")),
        Person(name: "Anne", address: Address(postcode: "W5")),
        Person(name: "Neil", address: Address(postcode: "N1")),
        Person(name: "Neil", address: Address(postcode: "A1")),
        Person(name: "Daniela", address: Address(postcode: "N1")),
        Person(name: "Luciano", address: Address(postcode: "SW4")),
      ])

      // We can specify a sectionNameKeyPath
      provider.sectionNameKeyPath = "address.postcode"

      // Finally, lets return our provider along with some additional filtering and sort functions
      return provider
        .filter { $0.address?.postcode != "SW4" }
        .sort { $0.address?.postcode < $1.address?.postcode }
        .sort { $0.name < $1.name }
    }
  }  

}

Ok, so that's a very verbose implementation, yours would probably be a lot cleaner.

Notice the we enforce the type just once on the var. This is great, because it means we can get type-safe compiler warnings when things go wrong.

So, what about the cell for our dataView? Populate provides a type-safe method for configuring your cells:

func dataCoordinator<V : DataView>(dataView: V, cellConfigurationForIndexPath indexPath: NSIndexPath) -> DataCellConfiguration {
  return DataCellConfiguration(dataView: dataView, reuseIdentifier: "Cell", registerCell: true, indexPath: indexPath, configuration: { (cell: UITableViewCell) in
    let person = dataCoordinator?.dataProvider.itemAtIndexPath(indexPath)
    cell.textLabel?.text = person?.name
  })
}

Ok, so setting up the cell looks complicated, but in actual fact, you're basically just passing the params through to the DataCellConfiguration.

This is a special class that allows multiple, type-safe cells to be configured from a single function.

You might also notice registerCell. This is on by default and basically tells Populate to automatically register the cell (using its type) for you. This means you don't need to register your cell beforehand ;)

Note: This will not work for cells loaded from storyboards or nibs. If you are using one of those, pass false here.

ArrayDataProvider

A DataProvider is simply a protocol, however Populate includes an array-based provider by default.

This allows you to pass a flat array, and get all the benefits you traditionally get via NSFetchedResultsController.

Features like, sectioning, sorting, filtering and even mutation are all available. PLUS you get automatic updates reflected in your DataView.

func add(item: T)
func delete(item: T)
func delete(atIndexPath indexPath: NSIndexPath)
func updateItem(atIndexPath indexPath: NSIndexPath, withItem newItem: T)

Note: All mutating functions are type-safe.

Platforms

Populate is supported on the following platforms & versions:

• iOS 8.0+

Installation

Populate is available through CocoaPods. To install it, simply add the following line to your Podfile:

pod "Populate"

Author

Shaps @shaps

License

Populate is available under the MIT license. See the LICENSE file for more info.