FirestoreClient 🔥

A generic based abstraction layer on top of Firestore.

Used Libraries

• Firebase/Firestore: a scalable NoSQL cloud database to store and sync data for client and server-side development.
• Google/Promises: a modern framework that provides a synchronization construct for Swift to facilitate writing asynchronous code.
• Identity: a small library that makes it easy to create type-safe identifiers in Swift.

Features

• Support Codable.
• Support Promises.
• Provide easy to use read and write operations.
• KeyPath based query builder.
• Type-safe identifiers.

Usage

Entity

Your model must be conformed to Entity protocol which conformed to Codable. For example:

struct Book: Entity {
    var id: ID = ""
    var title: String
    var author: String
    var releaseDate: Date?
    var pages: Int
}

Conform to QueryKey protocol to enable KeyPath query.

extension Book: QueryKey {
    static var keys: [PartialKeyPath<Book>: CodingKey] {
        return [
            \Self.id: CodingKeys.id,
            \Self.title: CodingKeys.title,
            \Self.author: CodingKeys.author,
            \Self.releaseDate: CodingKeys.releaseDate,
            \Self.pages: CodingKeys.pages
        ]
    }
}

UseCase

The usecase is a protocol which do one specific thing.

protocol BooksUseCase {
    func loadBooks() -> Promise<[Book]>
    func loadBook(byID id: Book.ID) -> Promise<Book>
    func saveBook(_ book: Book) -> Promise<Void>
    func updateBook(_ book: Book) -> Promise<Void>
    func deleteBook(byID id: Book.ID) -> Promise<Void>
}

Concrete implmentation of the BooksUseCase.

final class DefaultBooksUseCase<Repository: AbstractRepository> where Repository.Value == Book {
    private let repository: Repository
    
    init(repository: Repository) {
        self.repository = repository
    }
}

extension DefaultBooksUseCase: BooksUseCase {
    func loadBooks() -> Promise<[Book]> {
        return repository.query {
            $0.filter(by: \.author, equal: "George R. R. Martin")
              .order(by: \.releaseDate)
              .limit(to: 5)
        }
    }
    
    func loadBook(byID id: Book.ID) -> Promise<Book> {
        return repository.fetch(byID: id)
    }
    
    func saveBook(_ book: Book) -> Promise<Void> {
        return repository.save(entity: book)
    }
    
    func updateBook(_ book: Book) -> Promise<Void> {
        return repository.update(entity: book)
    }
    
    func deleteBook(byID id: Book.ID) -> Promise<Void> {
        return repository.delete(byID: id)
    }
}

UseCaseFactory

It helps to hide the concrete implementation of use case.

protocol UseCaseFactory {
    func makeBooksUseCase() -> BooksUseCase
}

final class DefaultUseCaseFactory: UseCaseFactory {
    func makeBooksUseCase() -> BooksUseCase {
        let path = Path("books")
        let repository = FirestoreRepository<Book>(path: path)
        return DefaultBooksUseCase(repository: repository)
    }
}

Installation

CocoaPods

CocoaPods is a dependency manager for Cocoa projects. For usage and installation instructions, visit their website. To integrate FirestoreClient into your Xcode project using CocoaPods, specify it in your Podfile:

pod 'FirestoreClient'

Then, run the following command:

$ pod install

Author

Anas Alhasani