Data-bound chart components 7/8: demo app on the new API

[FarhanAliRaza]

Stacked on #466. Base is stack/6-compile-probe. Top of the stack — check this branch out to see the whole feature.

Change

Ports examples/reflex to the tier the stack built, so the showcase is the API we recommend rather than the one it replaces:

• a composed 1M drillable scatter with hover/click/select;
• an on_view_change data var republishing in-view columns into a fixed histogram plan;
• a flat scatter whose slider republishes columns under a stable handle;
• an rx.cond toggle between a composed board and rx.foreach small multiples over a list[DataHandle] var.

The escape hatch stays represented on purpose. The cross-filtered histogram whose structure reads state keeps @reflex_xy.figure, alongside both fixed-data tiers and the FastAPI cross-host A/B — so the example shows where each tier is the right answer rather than implying the new one subsumes them.

reflex_ws_smoke.py drives the ported app; test_example_apps.py compiles it.

Spec

reflex-integration.md file map (examples/reflex inventory).

Test plan

• uv run pytest tests/reflex_adapter tests/test_validation_timing.py tests/test_example_apps.py — 250 passed, 1 skipped
• pre-commit run --all-files, ruff check, ruff format --check, ty check — clean
• Browser E2E (scripts/reflex_ws_smoke.py) against the running demo not re-run in this session — worth doing before merge.

[coderabbitai]

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[greptile-apps]

Greptile Summary

The PR ports the Reflex showcase to the data-bound chart API while retaining the figure, streaming, inline, and static tiers where appropriate.

• Adds composed and flat data-bound charts backed by typed @reflex_xy.data methods.
• Demonstrates view-driven republishing and conditional rx.foreach charts over typed handles.
• Updates the browser smoke probe, compile tests, documentation, and integration inventory for the expanded demo.
• Adds server-side validation and clamping for slider values that control allocation sizes.

Confidence Score: 5/5

The PR appears safe to merge.

No blocking failure remains; the prior unbounded allocation issue is closed because the only event-driven assignment clamps the point count before the data builder allocates its arrays.

Important Files Changed

Filename	Overview
examples/reflex/xy_reflex_demo/xy_reflex_demo.py	Ports the demo to typed data-bound components, adds conditional small multiples, and closes the previously reported unbounded allocation path with server-side clamping.
scripts/reflex_ws_smoke.py	Extends the live-browser smoke probe to cover the additional subscriptions, bound chart, and conditional foreach mounts.
tests/test_example_apps.py	Updates source and composition assertions to cover the new data-bound API examples and renamed inline handles.
spec/design/reflex-integration.md	Documents composite-token hydration, bounded resynchronization, and the updated Reflex example inventory.
README.md	Adds a state-driven data-bound chart example using typed column data.
examples/reflex/README.md	Updates the showcase guide and interaction checks for the nine-section data-bound demo.

_{Reviews (4): Last reviewed commit: "fix(reflex): clamp demo slider events se..." | Re-trigger Greptile}

[codspeed-hq]

Merging this PR will not alter performance

✅ 109 untouched benchmarks
⏩ 2 skipped benchmarks¹

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_{Comparing stack/7-demos-and-gallery (7c555e4) with stack/6-compile-probe (b3ebb05)}

Footnotes

1. 2 benchmarks were skipped, so the baseline results were used instead. If they were deleted from the codebase, click here and archive them to remove them from the performance reports. ↩

[cubic-dev-ai]

All reported issues were addressed across 6 files

<sub>Reply with feedback, questions, or to request a fix.

Fix all with cubic | Re-trigger cubic</sub>

[FarhanAliRaza]

Review addressed in 24569d2: the §2 set_bins and §8 set_bound_points events now validate the payload's list shape and clamp the number to the slider's min/max server-side (_clamped_slider_value) before assignment — slider limits are UI hints, not a security boundary, and both values size server allocations. The module docstring's section count is corrected.

Also, the /kinds page (stacked on top in 8/8) now has browser render coverage: scripts/reflex_ws_smoke.py step 7 navigates there and pixel-probes all 26 kind cells; the full smoke passes end to end against the running app (all 26 cells paint, one shared websocket, drill/stream/cond steps green).