dash-loading-components (dlc)

Loading indicators for Plotly Dash, wrapping nine React spinner libraries as one install. 107 components under stable namespaces, with a common factory over the top so you can switch families without relearning each one's props.

Browse them all in the live gallery: https://dash-loading-components.phylatech.com

pip install dash-loading-components

One contract, every component

import dash_loading_components as dlc

dlc.loading_dev.Dual(size=48, color="#f97316", rate=1.5)
dlc.premium.OrbitRings(size=48, color="#f97316", ring_count=4, playing=False)
dlc.ldrs.Ring(size=48, color="#f97316", stroke=5)

Every component takes the same four props with the same meaning:

Each library's own props are there too, in snake_case, in the library's own units: dlc.loading_dev.Arc(duration=1600, easing="stacked"), dlc.spinners.ClipLoader(speed_multiplier=2). A native tempo or pause prop passed alongside rate or playing wins.

Need a loading overlay? Use Dash's own:

dcc.Loading(children, custom_spinner=dlc.ldrs.Ring(size=48))

Discover what is available at runtime:

dlc.list_libraries()          # ['loading_dev', 'ldrs', 'spinners', ...]
dlc.list_spinners("ldrs")     # ['Ring', 'Helix', 'DotPulse', ...]

Requirements

React ≥19 and Dash ≥4.5, both hard requirements. The loading_dev family needs React 19, and this package will not claim Dash 4.4 / React 18 compatibility.

Dash 4.5 is not on PyPI as a stable release yet, so the dependency is pinned as dash>=4.5.0rc0. That specifier names the pre-release, which is what lets pip resolve it; it will accept the final 4.5 release once published.

Families

Every component is also exported prefixed at the top level (dlc.LoadingDevArc, dlc.LdrsRing) for Dash callbacks that want a flat name.

Version pins, SPDX licenses, upstream URLs and React peers: docs/UPSTREAM-INVENTORY.md. Attribution: NOTICE.

Relative tempo

rate is a rate, not a duration. 1.0 reproduces the tempo the upstream component runs at on its own, and the value is translated per family in the wrappers: a duration in milliseconds for loading-dev, epic and premium, seconds per loop for ldrs, a multiplier for react-spinners and m3, a percentage for spinners-react, an offset for react-loading-indicators.

That baseline is per spinner, not per family. loading_dev.Compass is normally 500ms and loading_dev.Slide is 2400ms, so rate=1.0 gives each of them its own tempo and rate=2.0 halves both. react-loader-spinner has no tempo prop, so rate does nothing there.

Compared with dash-loading-spinners

dash-loading-spinners is a focused package built largely around react-spinners-era indicators. dlc is not a rename or a silent re-export of it. The goals differ:

• A multi-upstream umbrella with stable namespaces, dlc.<family>.<Component>
• An explicit React 19 / Dash ≥4.5 floor, driven by loading-dev
• A license inventory and NOTICE covering every wrapped family
• Room to add families without flattening name collisions

Where the APIs overlap, credit upstream; this is honest coexistence, not a drop-in replacement.

Contributing

Pull requests only, against main. Family wrappers land as focused follow-up PRs, one family or a small batch per PR. Releases are cut by release-please from Conventional Commits merged to main, so commit subjects need a feat: / fix: / chore: prefix.

Local setup:

pixi install           # Python, Node, Dash, the gallery's deps, test tooling
npm install
pixi run build         # JS bundle + generated Python wrappers
pixi run python usage.py   # minimal demo app
pixi run gallery       # the full gallery, http://127.0.0.1:8050/
pixi run test

The deployed gallery runs under gunicorn (gallery:server); pixi run serve does the same locally.

pixi run build-js alone is enough when you have only changed React or CSS under src/.

License

MIT, Copyright (c) 2026 Phyla Technologies. See LICENSE. Wrapped third-party libraries remain under their own licenses, listed in the inventory.