[WIP] Use Observation in WorkflowSwiftUI #260
Closed
Conversation
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
`MainScreen` now no longer reacts properly to state changes.
square-tomb
changed the title
square-tomb
force-pushed
the
tomb/swiftui-testbed-observation
branch
from
f1ae774 to
32668e4
Compare
4 tasks
watt
added a commit
that referenced
this pull request
Aug 16, 2024
This is a complete implementation of Workflow-powered SwiftUI views using fine-grained observability to minimize render impact. It's based on the prototype in #276, and @square-tomb's previous prototype #260. Squares can learn more at go/workflow-swiftui. # Observation We're depending on Perception, Point-Free's backport of Observation. The approach to observable state is adapted from TCA's approach, with a custom `@ObservableState` macro that endows struct types with a concept of identity. In workflows, you must annotate your state with `@ObservableState`, and render a type conforming to `ObservableModel`, which wraps your state and sends mutations into the unidirectional flow. There are several built-in conveniences for rendering common cases, or you can create a custom type. On the view side, your `View` will consume a `Store<Model>` wrapper, which provides access to state, sinks, and any child stores from nested workflows. To wire things up, you can implement a trivial type conforming to `ObservableScreen` and map your rendering. It's *strongly* recommended to keep these layers separate: render a model, implement a view, and create a screen only where needed. This allows for compositions of workflows and views, which is difficult or impossible if rendering a screen directly. Check out the new ObservableScreen sample app for complete examples of most concepts being introduced here. I'll also write up an adoption guide that expands on each requirement. # SwiftPM The `@ObservableState` macro means we cannot ship `WorkflowSwiftUI` with CocoaPods. For now, this PR only removes WorkflowSwiftUI podspec, but it may be preferable to remove all podpsecs and migrate everything to SwiftPM to reduce the maintenance burden. To work on WorkflowSwiftUI locally, you can use [xcodegen](https://github.com/yonaskolb/XcodeGen) to create a project, similarly to how `pod gen` works.
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
Add this suggestion to a batch that can be applied as a single commit.
This suggestion is invalid because no changes were made to the code.
Suggestions cannot be applied while the pull request is closed.
Suggestions cannot be applied while viewing a subset of changes.
Only one suggestion per line can be applied in a batch.
Add this suggestion to a batch that can be applied as a single commit.
Applying suggestions on deleted lines is not supported.
You must change the existing code in this line in order to create a valid suggestion.
Outdated suggestions cannot be applied.
This suggestion has been applied or marked resolved.
Suggestions cannot be applied from pending reviews.
Suggestions cannot be applied on multi-line comments.
Suggestions cannot be applied while the pull request is queued to merge.
Suggestion cannot be applied right now. Please check back later.
An experimental adaptation of TCA's Observation beta for Workflow.
Development
Since CocoaPods doesn't support SPM package dependencies, you need to manually add package dependencies to
Development.xcodeprojafter eachpod gen.We currently depend on commit
acfbab4290adda4e47026d059db36361958d495cfrom theobservation-betabranch of swift-composable-architecture.For some reason this manually-added dependency works only in sample app targets. In framework targets,
importstatements yield an error llike: