Version 4.5.0rc1

[T4rk1n]

Second release candidate for 4.5.0.

• dash/version.py -> 4.5.0rc1
• npm sub-packages bumped to the next patch, since rc0 already published their x.5.0 versions to npm: dash-core-components 4.5.1, dash-html-components 4.5.1, dash-table 7.5.1, dash-renderer 3.5.1 (package.json + lockfile version fields + _dash_renderer.py __version__/external_url). Renderer rebuilt.
• CHANGELOG: entries for Set autoComplete="off" in date pickers #4014, Fix resource paths under Windows extended-length paths #4007, Fix callbacks registered twice when app/app.py runs as a script #4023 and fixes set_props to merge the existing payload instead of dropping when in background callbacks #4057 now link their PR (with Fixes for the issue), and added the missing entry for fix(callbacks): use . for dots in dict ID callback IDs to fix JSON.parse SyntaxError #3923.

Since rc0 (see CHANGELOG [Unreleased] for the full list)

Added

• DASH_SECRET_KEY and DASH_SHARED_STORAGE platform hooks (Add DASH_SECRET_KEY and DASH_SHARED_STORAGE platform hooks #4026)
• Async hook routes, with the request bound for FastAPI hook routes (Support async hook routes and bind the request for FastAPI hook routes #4027)
• Social media meta tags from app.title, app.description and app.image (Extend social meta tags #4024)
• scrollToTop prop on dcc.Link (Add configurable scroll-to-top behavior to dcc.Link #3976)

Fixed

• Streaming on multi-worker ASGI with Redis shared storage (Fix streaming on multi-worker ASGI with Redis shared storage #4054)
• Idle shared-storage topics are released (Release idle shared-storage topics #4016)
• CSRF header after the cookie v2 bump (Fix CSRF header after the cookie v2 bump #4066)
• set_props in background callbacks merges instead of dropping the payload (fixes set_props to merge the existing payload instead of dropping when in background callbacks #4057)
• Callbacks registered twice under reload or when run as a script (Fix callbacks registered twice under reload when Dash() gets an explicit name #4053, Fix callbacks registered twice when app/app.py runs as a script #4023)
• Dots in dict ID callback IDs (fix(callbacks): use . for dots in dict ID callback IDs to fix JSON.parse SyntaxError #3923)
• _setup_server race (Serialize Dash._setup_server under a lock and publish its flag last #3980)
• Resource paths under Windows extended-length paths (Fix resource paths under Windows extended-length paths #4007)
• FastAPI reload scope options forwarded (Forward FastAPI reload scope options #3987)
• autoComplete="off" in date pickers (Set autoComplete="off" in date pickers #4014)

Plus dependency updates (#4058 and the dependabot groups).

Before final 4.5.0

• Rename CHANGELOG [Unreleased] -> [4.5.0] - <date>
• Drop the rc1 from dash/version.py

[github-actions]

Dash performance benchmarks

⚠️ regressions to review

	scenario	metric	p90 (ms)	median	growth	baseline p90	note
⚠️	patch_append_toplevel	append_ms	133.3	91.0	2.85x	140.2	1.3x baseline (norm)
✅	callback_chain	chain_ms	321.7	310.8	0.98x	499.1
✅	callback_chain	graph_ms	1.5	1.5	1.0x	2.4
✅	callback_fanout	fanout_ms	59.8	52.4	0.87x	92.5
✅	deep_nesting	render_ms	47.7	42.8	1.08x	56.8
✅	full_children_replace	replace_ms	3344.9	1258.1	17.52x	4697.1
✅	initial_render_large	render_ms	468.0	433.8	1.01x	694.4
✅	initial_render_small	render_ms	89.1	69.0	1.01x	104.0
✅	patch_append_nested	append_ms	145.4	88.6	2.64x	192.3
✅	patch_scalar_update_large	update_ms	150.4	138.4	0.92x	202.9
✅	wildcard_all_resolve	wildcard_ms	195.0	186.4	1.0x	313.6
✅	wildcard_all_resolve	graph_ms	0.7	0.7	1.0x	1.3

growth = late-third / early-third per-op time; ~1 is flat, a large value means the per-op cost scales with accumulated state.

machine scale vs baseline: 0.72x - divided out of the baseline ratios so they compare like for like (the absolute warn/fail ceilings are left un-scaled); calibrated on initial_render_small.

[sonarqubecloud]

Quality Gate passed

Issues
0 New issues
0 Accepted issues

Measures
0 Security Hotspots
0.0% Coverage on New Code
0.0% Duplication on New Code

See analysis details on SonarQube Cloud