GenericCollectionView

The goal of the GCV is to reduce boilerplate code for similar structured views. GCV acccomplishes this by encapsulating the UICollectionView properties to GCVSection objects which in turn consists of GCVCell and GCVModel objects. These describe the properties of the different cells.

Usage

Setting up the view

Simply add an instance of GenericCollectionView to your view.

import UIKit
import GenericCollectionView

class ViewController: UIViewController {
    override func viewDidLoad() {
        super.viewDidLoad()

        let genericCollectionView = GenericCollectionView()
        genericCollectionView.translatesAutoresizingMaskIntoConstraints = false

        view.addSubview(genericCollectionView)
        NSLayoutConstraint.activate([
            genericCollectionView.topAnchor.constraint(equalTo: view.topAnchor),
            genericCollectionView.leadingAnchor.constraint(equalTo: view.leadingAnchor),
            genericCollectionView.bottomAnchor.constraint(equalTo: view.bottomAnchor),
            genericCollectionView.trailingAnchor.constraint(equalTo: view.trailingAnchor)
        ])
    }
}

Section Descriptors

Sections can be GCVStaticSection or GCVDynamicSection.

To describe a section the following properties can be set:

var inset: UIEdgeInsets
var minimumLineSpacing: CGFloat
var minimumInterItemSpacing: CGFloat

Item size can be set by overwriting

func gcvSection(sizeForItemAt index: Int) -> CGSize

A section can be added to the GenericCollectionView by calling

func update(sectionDescriptors new: [GCVSection])

Static Sections

Static sections are described by an array of tuples of GCVModel and a GCVCell.

To add a cell use

gcvAddItemToSection(viewModel: GCVModel, cell: GCVCell<GCVModel, CellType>)

Dynamic Section

Dynamic sections are described by a GCVCell and an array of GCVDynamicModel

The cell is defined by setting the class' cell property to an instance of GCVCell

The cells' viewModels are set by the viewModels property

Cell Descriptors

A Cell Descriptor is an instance of GCVCell a generic class which takes the following type parameters:

GCVCell<ViewModel: GCVModel, UICollectionViewCell>

a GCVCell can be described with the following methods

let cell = GCVCell<ExampleViewModel, ExampleCollectionViewCell>(fromNib: false)
cell.setupCell { viewModel, cell in
    // Setup Cell - Call in cellForItemAt
}

cell.willDisplayCell { viewModel, cell in
    // Will Display Cell
}

cell.isSelectable = true

cell.didSelectCell {
    // Did Select Cell
}

ViewModels

GCVModel

An empty protocol

protocol GCVModel { }

GCVDynamicModel

public protocol DynamicModel {
    var totalItemCount: Int? { get set }
    var index: Int? { get set }
}

public typealias GCVDynamicModel = (GCVModel & DynamicModel)

Header / Footer

A Header / Footer can be added to a section by setting headerViewType / footerViewType. headerViewType is a tuple of GCVModel and GCVReusableView

The size of Header / Footer is set by the sections properties

var referenceHeaderSize: CGSize
var referenceFooterSize: CGSize

GCVReusableView

A ReusableView descriptor is a generic class which takes the following type parameters:

class GCVReusableView<ViewModel: GCVModel, ReusableView: UICollectionReusableView>

A GCVReusableView is described with the following methods

let header = GCVReusableView<ExampleHeaderViewModel, ExampleHeaderView>(fromNib: false)
header { viewModel, reusableView in
    // Setup ReusableView
}

let footer = GCVReusableView<ExampleHeaderViewModel, ExampleHeaderView>(fromNib: false)
footer.setupReusableView { viewModel, reusableView in
// Setup ReusableView
}

Arestronaut / GenericCollectionView