CollectionKit

Framework to manage complex UICollectionView in declarative way and very few lines of code. Heavily inspired by https://github.com/maxsokolov/TableKit and https://github.com/Instagram/IGListKit

WARNING

Development still in progress. Some changes may affect backward compatibility

Features

• Declarative UICollectionView management
• No need to implement UICollectionViewDataSource and UICollectionViewDelegate
• Easy way to map your models into cells
• Auto diffing
• Supports cells & reusable views from code and xibs and storyboard
• Flexible
• Register cells and reusable views automatically
• Fix scroll indicator clipping at iOS11 (http://www.openradar.me/34308893)

Getting Started

Key concepts of CollectionKit are Section, Item and Director. Item is responsible for UICollectionViewCell configuration, size and actions Section is responsible for group of items and provides information for each item, header/footer and all kind of insets/margins: section insets, minimum inter item spacing and line spacing Director is responsible for providing all information, needed for UICollectionView and its updations

Basic usage

Setup UICollectionView and director:

Setup collection view

collectionView = UICollectionView(frame: view.bounds, colletionViewLayout: UICollectionViewFlowLayout())
collectionDirector = CollectionDirector(colletionView: collectionView)

Create items

let item1 = CollectionItem<CollectionCell>(item: "hello!")
let item2 = CollectionItem<CollectionCell>(item: "im")
let item3 = CollectionItem<CollectionCell>(item: "ColletionKit")
let item4 = CollectionItem<ImageCell>(item: "greeting.png")

Create section and put items in section

let section = CollectionSection()
let items = [item1, item2, item3, item4]
section += items
director += section

Put section in director and reload director

director += section
director.reload()

Cell configuration

Cell must implement ConfigurableCollectionCell protocol. You need to specify cell size and configure methods:

extension CollectionCell : ConfigurableCollectionItem {
    static func estimatedSize(item: String?, boundingSize: CGSize) -> CGSize {
        return CGSize(width: collectionViewSize.width, height: 50)
    }

    func configure(item: String) {
        textLabel.text = item
    }
}

Actions

Implement such actions like didSelectItem or shouldHighlightItem using functional syntax

let row = CollectionItem<CollectionCell>(item: "text")
    .onSelect({ (_) in
        print("i was tapped!")
    }).onDisplay({ (_) in
        print("i was displayed")
    })

Available actions:

• onSelect
• onDeselect
• onDisplay
• onEndDisplay
• onHighlight
• onUnighlight

Section configuration

You can setup inter item spacing, line spacing and section insets using section object:

let section = CollectionSection()
section.minimumInterItemSpacing = 2
section.insetForSection = UIEdgeInsetsMake(0, 20, 0, 20)
section.lineSpacing = 2

Updating

You can update collection view only by operating with section and item objects without any IndexPath mess: put usual operations in performUpdates block

self.director.performUpdates { [unowned self] in
    self.section.append(item: row)
    self.section.insert(item: row, at: 0)
    self.section.remove(item: item)
}

Custom sections

You can provide your own section implementations using AbstractCollectionSection protocol. For example, you can use it for using CollectionDirector with Realm.Results and save Results lazy behaviour or implementing expandable sections