Dependency Management With Carthage

Slides from my talk about Carthage at Cocoaheads Stockholm

The video is available at https://vimeo.com/165920026

Transcript

1. Dependency Management With Carthage Abizer Nasir | @abizern | abizern.org
2. ! How to use Carthage to manage dependencies. How to write a dependency that can be used with Carthage. How to make working with Carthage a little easier.
3. ! Whether or not dependencies are a good thing. Cocoapods.
4. Yet Another Dependency Manager
5. Git Git is a lot of things, but it’s not a dependency manager.
6. Cocoapods Code is stored in a central location 1. The code is built into a framework that is added to the project workspace. 1 They don’t have to be.
7. Swift Package Manage Library locations are specified in Package file. Builds dependencies as libraries (the irony!). Only for Desktop.
8. Carthage Developed after Swift and framework support in iOS. Dynamic libraries built according to their own project settings. Dependencies are dynamic frameworks and supported by OS X and iOS 2. 2 All versions of OS X, iOS 8+
9. Decentralised and designed for simplicity. You need to find third party projects yourself. You need to integrate the code into your project manually. Doesn’t (and probably won’t) do a lot of cool stuff that Cocoapods can do.
10. Getting Carthage
11. Install Binary release. https://github.com/Carthage/Carthage/releases
12. Install using Homebrew (recommended) brew update && brew install carthage You may need to use xcode-select to choose the correct version of Xcode/Swift to build the tool.
13. What Does Carthage do? » Takes a list of dependencies, that may have their own dependencies. » Resolves versions semantically. » Fetches the dependencies at the correct versions. » Builds them with their own project settings - (optional).
14. That’s it! The rest is up to you!
15. Adding Dependencies (Recommended3) » Specify dependencies in the Cartfile. » Fetch and build the dependencies. » Link the frameworks to the correct target. » Copy the dSYM files to the target. » Add a workaround script for iOS targets. 3 As recommended by the documentation, but not the only way.
16. Cartfile - Specify public dependencies. github “ReactiveCocoa/ReactiveCocoa” >= 2.3.1 github “Mantle/Mantle” ~> 1.0 github “jspahrsummers/libextobjc” == 0.4.1 #arbitrary server git “https://enterprise.local/desktop/git-error-translations.git” “development” #local file git “file:///directory/to/project” “branch”
17. Normal Semantic versioning rules. » >= 1.0 for “at least version 1.0” » ~> 1.0 for “compatible with version 1.0” » == 1.0 for “exactly version 1.0” » some-branch-or-tag-or-commit for a specific Git object (anything allowed by git rev-parse)
18. Cartfile.private Same format as the Cartfile. Dependencies that your project needs that aren’t necessary for it to be used. These are not shared upstream. For example; things you need for testing, things you need for building.
19. Cartfile.resolved This is where the actual versions to be used are written to. If you’re familiar with gemfile.lock, podfile.lock, you know what these are.
20. Demo Using Carthage
21. carthage update Resolves dependencies and builds them. If you only want to update one or some dependencies. Carthage update xxx
22. carthage help update Update and rebuild the project's dependencies [--configuration (string)] the Xcode configuration to build (ignored if --no-build option is present) [--platform (platform)] the platforms to build for (one of ‘all’, ‘Mac’, ‘iOS’, ‘watchOS’, 'tvOS', or comma-separated values of the formers except for ‘all’) (ignored if --no-build option is present) [--derived-data (string)] path to the custom derived data folder [--verbose] print xcodebuild output inline (ignored if --no-build option is present) [--no-checkout] skip the checking out of dependencies after updating [--no-build] skip the building of dependencies after updating (ignored if --no-checkout option is present) [--use-ssh] use SSH for downloading GitHub repositories [--use-submodules] add dependencies as Git submodules [--no-use-binaries] check out dependency repositories even when prebuilt frameworks exist, disabled if --use-submodules option is present (ignored if --no-build option is present) [--color (color)] whether to apply color and terminal formatting (one of ‘auto’, ‘always’, or ‘never’) [--project-directory (string)] the directory containing the Carthage project [[]] the dependency names to update, checkout and build
23. carthage bootstrap Uses Cartfile.resolved to build dependencies. This is what is usually used when checking out a project. Note: If you are using submodules update the submodules first and then run build: git submodule update --init carthage build
24. def run(command) system(command) or raise "RAKE TASK FAILED: #{command}" end namespace "carthage" do desc "Bootstrap carthage dependencies" task :bootstrap do |t| run "git submodule update --init" run "carthage bootstrap --use-submodules --platform ios" end desc "Update carthage dependencies" task :update do |t| run "carthage update --use-submodules --platform ios" end end task :default do system "rake -T" end
25. carthage build Just builds what you have already. This is useful if you are using submodules.
26. Writing modules » Share your build schemes » Link any dependencies, don’t add them to the bundle. » When writing a Foundation module, create a separate target for iOS and Mac, tvOS, watchOS (takes some tweaking, but it can be done).
27. Demo Writing a Framework for Carthage
28. Artefacts Cartfile, Cartfile.resolved should be checked in to version control Carthage/Checkouts, Carthage/Build - It depends Use submodules and Carthage/Checkouts problem goes away.
29. When things go wrong ! Because they will! - Check what compiler you are using with xcode-select -p - fix your build with carthage build --no-skip-current, build the scheme to see more detailed errors. - Blitz Carthage folder and Cartfile.resolved - Blitz the cache at ~/Library/Caches/carthage - Bitcode!
30. When it all goes completely wrong! !! Because it will! » Change the Carthage update method to use submodules and not build. » Remove the linked frameworks. » Drag the dependency project files into your project and build it “old school”.
31. So...
34. Simple
35. Easy
36. Carthage is simple, not easy. CocoaPods is easy, not simple.
38. Git
39. Thank You Abizer Nasir | @abizern | abizern.org