Making Sourcery write code for you

38º CocoaHeads BH

Github: https://github.com/marciliojrs/making-sourcery-write-code-for-you

Transcript

1. Making Sourcery write code for you Network Layer
2. 38º CocoaHeads BH
3. Marcílio Júnior iOS Developer @ Teamwork Teacher @ PUC Minas #iOSDev since 2011 #RemoteWorker since 2014
4. Who writes boilerplate code every day?
5. What can I do if remove it from my life?
11. Agenda 1. What is meta programming 2. What is Sourcery 3. Stencil 4. Using Sourcery to write your API client
12. Meta programming
13. Technique in which a computer program can be designed to read, generate, analyze or transform other programs, and even modify itself while running.
14. What is meta-programming? • Some languages that have this feature: ◦ Ruby ◦ Python ◦ Rust ◦ Elixir ◦ Smalltalk
15. Where's Swift in this list?!
16. Sourcery
17. Stop writing boilerplate code
18. How it works?
19. Why use Sourcery? 1. Less repetitive code to write (DRY principles) 2. Allows create better code 3. Limits the risk of introducing human error when refactoring 4. Less code less bugs
20. Download and documentation https://github.com/krzysztofzablocki/Sourcery
21. Using templates Stencil
22. {% for enum in types.implementing.AutoCases|enum %} {{ enum.accessLevel }} extension {{ enum.name }} { static let count: Int = {{ enum.cases.count }} {% if not enum.hasAssociatedValues %} static let allCases: [{{ enum.name }}] = [ {% for case in enum.cases %} .{{ case.name }}{{ ',' if not forloop.last }}{% endfor %} ] {% endif %} } {% endfor %}
23. Live Demo Sourcery
24. Network Layer with Sourcery
25. Why generate my network client?
26. 1. Request manager 2. API Protocol 3. API Implementation Network Layer
27. protocol ApiClientProtocol { func fetchAll(completion: @escaping ((Result<[Todo], Error>) -> Void)) } class ApiClient: ApiClientProtocol { func fetchAll(completion: @escaping ((Result<[Todo], Error>) -> Void)) { // ... build URL URLSession.shared.dataTask(with: url) { (data, _, error) in guard let data = data else { completion(.failure(error!)) return } let todos = try! JSONDecoder().decode([Todo].self, from: data) completion(.success(todos)) }.resume() } }
28. How do I add new methods?
29. class ApiClient: ApiClientProtocol { func fetchAll(completion: @escaping ((Result<[Todo], Error>) -> Void)) { // ... build URL URLSession.shared.dataTask(with: url) { (data, _, error) in guard let data = data else { completion(.failure(error!)) return } let todos = try! JSONDecoder().decode([Todo].self, from: data) completion(.success(todos)) }.resume() } }
30. What if we can just declare the protocol?
31. func fetchAll(completion: @escaping ((Result<[Todo], Error>) -> Void)) protocol ApiClientProtocol { }
32. // sourcery: baseUrl = "https://base.url.com" // sourcery: path = "/todo" // sourcery: method = .get // sourcery: contentType = "application/json" // sourcery: token = "token" // sourcery: response = [Todo] func fetchAll(completion: @escaping ((Result<[Todo], Error>) -> Void)) protocol ApiClientProtocol { }
33. Live Demo API Client
34. Conclusion 1. Less repetitive code to write (DRY principles) 2. Allows create better code 3. Limits the risk of introducing human error when refactoring 4. Less code less bugs
35. Conclusion 1. Less repetitive code to write (DRY principles) 2. Allows create better code 3. Limits the risk of introducing human error when refactoring 4. Less code less bugs
36. Conclusion 1. Avoid copy/pasting 2. Allows create better code 3. Limits the risk of introducing human error when refactoring 4. Less code less bugs
37. Conclusion 1. Avoid copy/pasting 2. Allows create better code 3. Limits the risk of introducing human error when refactoring 4. Less code less bugs
38. Conclusion 1. Avoid copy/pasting 2. Efforts in the stencil template and where matters 3. Limits the risk of introducing human error when refactoring 4. Less code less bugs
39. Conclusion 1. Avoid copy/pasting 2. Efforts in the stencil template and where matters 3. Limits the risk of introducing human error when refactoring 4. Less code less bugs
40. Conclusion 1. Avoid copy/pasting 2. Efforts in the stencil template and where matters 3. Only one place to refactor 4. Less code less bugs
41. Conclusion 1. Avoid copy/pasting 2. Efforts in the stencil template and where matters 3. Only one place to refactor 4. Less code less bugs
42. Conclusion 1. Avoid copy/pasting 2. Efforts in the stencil template and where matters 3. Only one place to refactor 4. Less code less bugs
43. Thanks Please follow us at @teamwork Download talk at https://bit.ly/2MmaxGg Follow me at @marciliojrs