styled-components-custom-properties-theme-provider

v1.0.0-beta.3

Published

3 years ago

Custom styled-components theme provider which uses CSS custom properties in browsers that support them. Will fallback to using styled components theme provider implementation in browsers that don't support CSS custom properties.

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bjankord

styled-components theme-provider theming css custom properties css variables css theming

styled-components-custom-properties-theme-provider

This project is in initial concept development stages and may not be ready for production use.

Install

With npm:

npm install styled-components-custom-properties-theme-provider

With yarn:

yarn add styled-components-custom-properties-theme-provider

Demo

https://bjankord.github.io/styled-components-custom-properties-theme-provider/

Usage

Constraints

The CSS Custom Property Theme Proivder returns its children when rendering, so it must only wrap a single child node, similar to how the <ThemeProvider> component works from styled-components.

This single child node must be a DOM element, e.g. (this can't be a React.Fragment node), as this element is used to set inline styles for the CSS custom properties.

Another constraint is that your keys in your theme need to be a flat, single level with the key names being values that can be uses as CSS custom properties. eg. "button-background-color": "mediumseagreen"

Performance Notes

Originally, I started exploring this idea thinking this would be faster for theming as the styled component wouldn't need to read multiple items off of the theme object.

I've set up 3 pages to test 3 implementations.

In testing I've found that using the CSS custom properties based theme provider (without including fallback support for browsers that don't support CSS properties) is faster compared to the default styled-components theme provider.

However, the implementation that uses the CSS custom properties based theme provider and falls back to using the the default styled-components theme provider is noticeably slower when throttling the CPU to 4x slowdown in Chrome compared to using the default styled-components theme provider. This can be seen in the demo when changing themes.

Testing with React.unstable_Profiler

I've wrapped the theme provider in each demo with a Profiler component from React.unstable_Profiler;

Below is the mean average from 20 test runs for each demo collected from running create-react-app in development mode.

Tested in production mode in CRA thanks to @bvaughn's gist here: https://gist.github.com/bvaughn/25e6233aeb1b4f0cdb8d8366e54a3977

Production Mode

MOUNT phase:

| Measure | Styled Components ThemeProvider | CSS Custom Properties Theme Provider | CSS Custom Properties Theme Provider With Fallback | |---|---|---|---| | Actual time: | 114.67500089202076 ms | 65.54000021424145 ms | 122.44500109227374 ms | | Base time: | 93.18000212078914 ms | 44.91499869618565 ms | 99.71500077517703 ms |

UPDATE phase:

| Measure | Styled Components ThemeProvider | CSS Custom Properties Theme Provider | CSS Custom Properties Theme Provider With Fallback | |---|---|---|---| | Actual time: | 42.78000054182485 ms | 18.06499983649701 ms | 52.99499997636303 ms | | Base time: | 39.890000072773546 ms | 15.694999718107283 ms | 50.529999658465385 ms |

Update phase was tested by supplying a new theme with entirely different values for each theme property.

Development Mode

MOUNT phase:

| Measure | Styled Components ThemeProvider | CSS Custom Properties Theme Provider | CSS Custom Properties Theme Provider With Fallback | |---|---|---|---| | Actual time: | 243.0450000683777 ms | 234.49500190326944 ms | 272.86500280024484 ms | | Base time: | 182.36999865621328 ms | 177.84500279230997 ms | 209.2250018613413 ms |

UPDATE phase:

| Measure | Styled Components ThemeProvider | CSS Custom Properties Theme Provider | CSS Custom Properties Theme Provider With Fallback | |---|---|---|---| | Actual time: | 97.6450014859438 ms | 89.05499934917316 ms | 108.44500467646867 ms | | Base time: | 87.12000423111022 ms | 79.05499776825309 ms | 99.06000515911728 ms |

Update phase was tested by supplying a new theme with entirely different values for each theme property.

Testing with puppeteer

| Measure | Styled Components ThemeProvider | CSS Custom Properties Theme Provider | CSS Custom Properties Theme Provider With Fallback | |---|---|---|---| | Total page time from start to load: | 428ms | 398ms | 489ms | | Time spent constructing the DOM tree: | 179ms | 165ms | 179ms | | Time spent rendering: | 409ms | 374ms | 466ms |

tl;dr

The CSS custom properties theme provider is a bit faster compared to the the default styled-components theme provider.

If you do need to support browsers that don't support CSS custom properties, the default styled-components theme provider will be faster compared to the CSS Custom Properties Theme Provider which offers fallback support.