Build a lego app with CocoaPods
- 1. Building a LEGO ® app with CocoaPods
Playing with bricks
@artheyn @cocoanantes
- 3. Solutions
3
• Using git submodules
‣ Hard to maintain with a lot of dependencies
‣ Hard to manage a proper versioning for each module
‣ Easy to link
‣ Versioning management and locking for free
• Using a package manager
- 4. Overview
• Slicing the app: iAdvize App case study
4
• In practice: build & use bricks
• Pros & Cons
• The wrong way
• Our modules
• Conclusion
- 5. 5
1. Identify the main app domains which will form our bricks
2. Separate each brick from the main app
3. Reconstruct the main app by linking the bricks together
Slicing the app
Steps
- 13. 13
• Using an internal pod repo
‣ Useful for strict versioning
‣ Useless if you want to point a dependency directly to a branch
• Using direct git repository link with a specific branch
pod 'iAdvizeLoggerLibrary', :git => 'ssh://(…)/mobile-ios-logger-library.git', :branch => 'master'
Step 3
Rebuild with CocoaPods
Two different ways to manage dependencies:
- 15. 15
Sample of a Podfile in the main application
def app_pods
# COCOAPODS EXTERNAL DEPENDENCIES
# HTTP requests.
pod 'Alamofire', '~> 4.0'
# (…)
# COCOAPODS INTERNAL DEPENDENCIES
# User service (user-related data storage)
pod 'iAdvizeUserService', :git => 'ssh://git@github.com/iadvize/mobile-ios-user-service.git', :branch => 'master'
# Account service (user profile)
pod 'iAdvizeAccountService', :git => 'ssh://git@github.com/iadvize/mobile-ios-account-service.git', :branch => 'master'
# Components library (reusable UI components)
pod 'iAdvizeComponentsLibrary', :git => 'ssh://git@github.com/iadvize/mobile-ios-components-library.git', :branch => 'master'
end
Step 3
Rebuild with Cocoapods
- 16. In practice
16
CocoaPods and the power of the `path`
App
Podfile
Login
Workspace
Pods
Workspace
Podfile
Pods
pod 'iAdvizeLoginService', :path => '../mobile-ios-login-service'
:path => ‘../login’
Login
- 17. In practice
17
CocoaPods and the power of the `path`
• Editing directly module files in the main app workspace like
if the module was directly in your app
‣ Impossible with Carthage!
• Test locally the integration of a module in the main app
- 19. In practice
19
Module usage
pod 'iAdvizeConversationService', :git => ‘ssh://(…)/mobile-ios-conversation-service.git’, :branch => 'master'
1. Add module dependency in the Podfile
2. Import, configure and use your module in your app
import iAdvizeConversationService
ConversationServiceManager.shouldDisplayPrincipalImageInChat = true
let conversationRootViewController = ConversationServiceManager.initialViewController() as! UISplitViewController
addControllerToTabBar(conversationRootViewController, at: 0)
- 20. In practice
20
Application: Orchestrator of modules
• Almost empty and deserves as a module orchestrator
• Instantiates, configures and displays each module
• Observes modules events (notifications) and actions
(delegate)
• Can forward events between modules
- 21. In practice
21
Module: Reusable brick
• Contains all the sources of a domain (including tests)
• Exposes events that apps or modules can observe
• Provides a way to configure it
• Provides an initial view controller (if it contains some UI)
• In a separate project
- 22. Git workflows
22
In our applications
‣ git-flow
In our modules
‣ “github like” workflow working with master, feature branches and tags
for production versions
- 23. Pros
23
• Fully separated and reusable modules
‣ Helps to have a proper architecture and avoid duplications
• Each module has its own Xcode project so it can be developed, run
and tested independently (without integrating it in a main application)
‣ Can even be shipped as a single module app for acceptance tests
• Lighter Xcode project which means low build time when you work on
a module
• Easy to integrate with the CocoaPods local link (path)
• Even if we don’t use strict versioning, we get the benefits of module
version locking with the Podfile.lock
• More modules -> more chance you have to work alone at a time ->
less conflicts
- 24. Cons
24
• Some configuration files has to be duplicated
‣ Continuous integration, lint, localizables, run scripts…
• Multiple Podspec and Podfile to work with and maintain
• Switching module dependency from remote repository to local
sources and vice versa has to be done manually in the Podfile
pod 'iAdvizeLoggerLibrary', :git => ‘(…)mobile-ios-logger-library.git’, :branch => 'master'
pod 'iAdvizeLoggerLibrary', :path => ‘../mobile-ios-logger-library’
- 26. The Wrong Way
26
(For us)
• Using an Internal Cocoapods specs repository was not relevant
‣ Use the git repository direct link feature of CocoaPods and point to a
specific branch
• Trying to use strict versioning on modules can quickly turn into a
nightmare
‣ No versioning is applied to our modules. The Podfile.lock prevent from
accidental updates and as we own our dependencies we are full aware of
break changes
• Applying a complex git workflow in the modules repositories is time-
consuming
‣ Using a single branch with tags for versions in production seems to be
the best solution