GOWDKdocs

Engineering

Implementation Plan: Bounded Markup Transitions

Context

Relevant spec, issue, ADR, or discussion:

Assumptions

  • Transition and animation names are literal CSS hook names.
  • This slice targets JS islands for client g:if and keyed client g:for.
  • Server-rendered server {} regions remain static request-time HTML and do not get transition hooks.

Proposed Changes

  • Add g:transition and g:animate to the closed directive set.
  • Validate motion directive values and placement in viewrender.
  • Emit data-gowdk-transition and data-gowdk-animate attributes.
  • Extend island.js conditional and keyed-list lifecycles with class toggles, transition/animation end handling, and fallback cleanup.
  • Update docs, stability metadata, and conformance coverage.

Files Expected To Change

  • internal/viewparse/directives.go
  • internal/viewrender/directives.go
  • internal/viewrender/element.go
  • internal/viewanalysis/contract_references.go
  • internal/clientrt/assets/island.js
  • internal/lang/stability.go
  • internal/lang/conformance_coverage_test.go
  • internal/viewrender/view_test.go
  • internal/buildgen/islands_test.go
  • docs/compiler/generated-output.md
  • docs/language/components.md
  • docs/language/diagnostics.md
  • docs/language/markup.md
  • docs/language/stability.md
  • docs/product/requirements.md
  • docs/product/roadmap.md

Data And API Impact

  • Public .gwdk markup gains two accepted directives.
  • Generated HTML gains compiler-owned data-gowdk-transition and data-gowdk-animate attributes.
  • No manifest shape changes.

Tests

  • Unit: internal/viewrender directive validation and rendering tests.
  • Integration: internal/buildgen generated HTML/runtime source tests.
  • End-to-end: browser island smoke for enter, leave interruption, and reorder.
  • Manual: no separate example is required for this first slice; docs include the minimal CSS contract.

Verification Commands

go test ./internal/viewparse ./internal/viewrender ./internal/viewanalysis ./internal/clientrt ./internal/buildgen ./internal/lang ./internal/diagnostics
go build ./cmd/gowdk
go test ./...
scripts/test-go-modules.sh

Rollback Plan

  • Remove the directives from the supported set and revert the runtime class toggles. Existing generated output without these directives is unaffected.

Risks

  • Class names could collide if unprefixed; the implementation uses gowdk-*.
  • CSS transitions without an end event need a deterministic fallback cleanup.
  • Reordering must not disturb keyed row reuse or event listener rebinding.