Things move fast around TCA and Apple-land! In all likelihood tca-beam isn't useful with the current version of TCA. I'll be revising tca-beam shortly to review the situation.

I love The Composable Architecture by PointFree.

And I'd like to spend less time copying, pasting, and renaming boilerplate for new features, and more time developing my features!

Enter tca-beam. This tiny tool generates a compiler-ready basic Reducer and View for all the feature names you give it. Put a spring in your step!

Higher-order reducers are being added to Beam; see the --make-hor flag for the first iteration.

With the lovely addition of @Observable and macros to Swift, TCA code promises to get a good bit simpler. Let's see.

To create compile-ready code for many features (feature = reducer + view), with one swift file per feature:

❯ tca-beam Login Help PersonalDetails Products Inbox Settings

tca-beam is preparing two-by-fours...

- Feature 'Login':
-    Creating file LoginView.swift
- Feature 'Help':
-    Creating file HelpView.swift
- Feature 'PersonalDetails':
-    Creating file PersonalDetailsView.swift

[... etc.]

tca-beam doesn't create or alter Xcode projects; you will need to do the usual "Add files" in your project.

The above example creates separate features -- they don't know anything about each other.

If you'd like to generate a higher-order reducer that has sub-reducers, use --make-hor.

For example, suppose you want a Thermostat reducer that has two sub-reducers TempSensor and Heater:

❯ tca-beam --force-overwrite --make-hor Thermostat TempSensor Heater

The first feature/reducer name given, Thermostat, is the HOR. The code generated for it Scopes in the other two reducers in the usual way and generates a skeleton switch on the sub-reducer actions.

Search the generated code for // Beam-TODO to see where you might start fleshing out your skeleton code.

tca-beam aims to be:

• low friction (it's a Python command tool that is quickly installed with pip)
• very simple to use in its default behaviour (feature names are all it demands)
• easily configurable, if the defaults don't suit you
• a project which is easy to extend or update later (it uses the Jinja template engine)

Install and update using pip:

$ pip install -U tca-beam

tca-beam creates files/folders relative to your current directory by default. It won't overwrite any existing files unless you use --force-overwrite.

To create three feature stubs based on the names Login, Help, PersonalDetails:

❯ tca-beam Login Help PersonalDetails

tca-beam is preparing two-by-fours...

- Feature 'Login':
-    Creating file LoginView.swift
- Feature 'Help':
-    Creating file HelpView.swift
- Feature 'PersonalDetails':
-    Creating file PersonalDetailsView.swift

Each file above contain both the reducer and the View for a feature.

If you like separation of View from Reducer, you can ask for that:

❯ tca-beam --two-files Login Help PersonalDetails

- Feature 'Login':
-    Creating file LoginViewFeature.swift
-    Creating file LoginView.swift
- Feature 'Help':
-    Creating file HelpViewFeature.swift
-    Creating file HelpView.swift
- Feature 'PersonalDetails':
-    Creating file PersonalDetailsViewFeature.swift
-    Creating file PersonalDetailsView.swift

And if you want each feature in its own folder, that's on the menu too:

❯ tca-beam --sub-dirs --two-files Login Help PersonalDetails

- Feature 'Login':
-    Creating file LoginFeature/LoginViewFeature.swift
-    Creating file LoginFeature/LoginView.swift
- Feature 'Help':
-    Creating file HelpFeature/HelpViewFeature.swift
-    Creating file HelpFeature/HelpView.swift
- Feature 'PersonalDetails':
-    Creating file PersonalDetailsFeature/PersonalDetailsViewFeature.swift
-    Creating file PersonalDetailsFeature/PersonalDetailsView.swift

The --dry-run switch is really useful for checking out the behaviour without generating any files:

❯ tca-beam --dry-run Login Help PersonalDetails

- (DRY RUN:) Feature 'Login':
- (DRY RUN:)    Creating file LoginView.swift
- (DRY RUN:) Feature 'Help':
- (DRY RUN:)    Creating file HelpView.swift
- (DRY RUN:) Feature 'PersonalDetails':
- (DRY RUN:)    Creating file PersonalDetailsView.swift

There's a switch --preview-all which additionally generates an AllPreviews.swift file. This is single SwiftUI preview that contains all the feature views in one VStack. It's particularly useful if your features are limited in size, e.g. UI controls or thumbnails, and you want to see them all at once.

Beam has defaults for how it names files, but you can change the filename style:

❯ tca-beam --customise-settings

I've copied default settings to '/Users/alexhunsley/.beam-settings.toml'.
Please edit this file with your favourite text editor.

To go back to the default settings, just delete this file.

To get help on command flags, run the command without parameters:

❯ tca-beam
Usage: tca-beam [OPTIONS] [FEATURE_NAMES]...

Options:
  --two-files           Put view and reducer into separate files
  --sub-dirs            Put each feature in a sub-directory
  --preview-all         Generate a single View that previews all feature Views
  --output-dir TEXT     Output directory (defaults to current dir)
  --force-overwrite     Force overwriting any existing files
  --dry-run             Don't generate files, just preview any actions
  --customise-settings  Generate a user-editable file to tweak file naming
                        settings.
  --version             Print version and exit
  --help                Show this message and exit.

• add more higher order reducers
• creation of navigation stacks with sub-features (perhaps using decoupled navigation)
• stub out unit test using e.g. TestStore

There are other tools, of course, which will allow you to do something similar:

• Xcode templates
• Meta-programming using e.g. Sourcery

Beam hopes to differentiate itself by working towards to allowing easy creation of higher-order reducers + sub-reducers. This will allow quickly generated starting points for common patterns like navigation.

Contributions are encouraged: PRs or suggestions, feedback on template contents, etc.

tca-beam is powered by Jinja (lovely templating) and click (composable command line interface creation).

And obviously, a large hat-tip to The Composable Architecture by PointFree.