restage_codegen 1.1.0

Write your UI as real Flutter widgets — your own design system, not a dialect — and restage_codegen compiles it into the blobs the Restage SDK ships over the air.

restage_codegen

The build-time code generator for the Restage SDK. It runs under build_runner and translates idiomatic Flutter widget source (annotated source classes and hand-authored .rfwtxt files) into the .rfwtxt / .rfw artifacts and catalogs the SDK runtime consumes.

Restage is server-driven UI for Flutter: a surface is authored in standard Flutter syntax, compiled to a Remote Flutter Widget (RFW) blob, and delivered to the app at runtime. This package is the source -> blob half of that pipeline for surfaces authored as Dart. The same machinery serves every surface type (paywalls, onboarding, in-app messages, surveys, or any other surface), not one in particular.

You author in ordinary Flutter idioms, not a helper vocabulary or shim widgets. The generator lowers a broad set faithfully (Text.rich, Theme.of(context), Navigator.push, showModalBottomSheet, PageView, NumberFormat, structured style values, the selection controls, and pure-composition custom widgets) and fails loudly at build time on anything it can't represent, never a silent partial render.

Emitting a genui A2UI catalog from your widgets? The same generator projects a genui A2UI catalog from your @RestageWidget source. Follow the step-by-step A2UI walkthrough. It covers the dependencies, the build.yaml setting, and the build command, with a worked example.

How it's wired

You don't import this package's library API in app code. It is a set of build_runner builders, declared in build.yaml and applied automatically to dependents (auto_apply: dependents). You add it as a dev_dependency and run dart run build_runner build; the builders pick up the right inputs by file location and write their outputs alongside them.

The builders are:

• restageCodegenBuilder translates a surface authored as Flutter source (an annotated class) or as a hand-authored .rfwtxt under lib/paywalls/ into the .rfwtxt + .rfw blob, a capability manifest, and a navigation plan.
• paywallFlowBuilder emits the declarative flow document for a surface whose source navigates across more than one screen.
• onboardingScreenBuilder translates an onboarding screen source into a typed screen descriptor (.rsscreen.g.dart) plus its .rfwtxt / .rfw blob and capability manifest.
• onboardingFlowBuilder emits the typed flow descriptor (.rsflow.g.dart) and flow document for a multi-screen flow.
• userCatalogBuilder walks a package for @RestageWidget-annotated classes and emits a single aggregated customer catalog.

(Two further internal builders register catalog factory functions and the customer's widget factories for the runtime; these support the SDK's own packages.)

What it produces

From a single surface source, the generator emits:

• .rfwtxt: the human-readable Remote Flutter Widget text form.
• .rfw: the compiled binary blob the SDK runtime decodes and renders.
• A capability manifest (.capability.json): the capability floor the blob declares, so an older reader fails closed rather than misrendering.
• A flow document / navigation plan: the declarative multi-screen topology, for surfaces that move between screens.
• Generated Dart descriptors: typed screen/flow accessors for onboarding-style flows.

Everything it emits is inert data: references and literal values, never executable code. The widget capability set and event handlers ship in your app release.

The generator transpiles standard Flutter widget trees, decomposes structured Flutter types (TextStyle, ButtonStyle, EdgeInsets, BoxDecoration, border radii, gradients, and others), folds constants, lowers theme reads to declarative theme bindings, and derives the capability manifest from the widgets a surface actually references.

It also has an A2UI emit target: from the same Flutter source it lowers to RFW, it can project a versioned A2UI (genui) catalog carrying the same capability contract. RFW remains the delivery wire; the A2UI projection is an additional, optional emit target. For the full opt-in setup, see the step-by-step A2UI walkthrough.

License

Licensed under the Functional Source License, Version 1.1, ALv2 Future License (FSL-1.1-ALv2): free for all use except building a competing product; each release automatically becomes Apache-2.0 two years after publication. See LICENSE for the full terms.