react-style-stringify

A utility for converting React CSSProperties objects or Record<string, CSSProperties> into CSS strings.

This utility was originally created to simplify the process of adding inline CSS styles to HTML email templates in a React project. Previously, all styles were written as plain strings, which became unmanageable as the project grew. To make styles more maintainable and consistent, this utility was developed to convert React CSSProperties objects into CSS strings, streamlining the process of embedding styles in the final HTML before sending emails.

Features

• Converts a single CSSProperties object to a CSS string.
• Converts a Record<string, CSSProperties> map to a CSS string.
• Automatically adds units (e.g., px) where necessary.
• Optionally injects the !important statement for each style property.

Installation

npm install react-style-stringify

or

yarn add react-style-stringify

Note

This package uses the CSSProperties type from @types/react.

If you're working with TypeScript and don't use React, install @types/react.

Usage

Import utils

import {
  stringifyCSSProperties,
  stringifyStyleMap,
} from "react-style-stringify";

Convert a single CSSProperties object

const cssString = stringifyCSSProperties({
  flex: 1,
  padding: 20,
  backgroundColor: "teal",
});
// Output: "flex:1;padding:20px;background-color:teal;"

Inject !important into CSS string

const importantCssString = stringifyCSSProperties(
  {
    flex: 1,
    padding: 20,
    backgroundColor: "teal",
  },
  true
);
// Output: "flex:1!important;padding:20px!important;background-color:teal!important;"

Convert a Record<string, CSSProperties> object

const cssMapString = stringifyStyleMap({
  p: {
    margin: 0,
    color: "teal",
  },
  "#root ul.my-list > li": {
    padding: 10,
  },
});
// Output: "p{margin:0;color:teal;}#root ul.my-list>li{padding:10px;}"

Inject !important into CSS string

const importantCssMapString = stringifyStyleMap(
  {
    p: {
      margin: 0,
      color: "teal",
    },
    "#root ul.my-list > li": {
      padding: 10,
    },
  },
  true
);
// Output: "p{margin:0!important;color:teal!important;}#root ul.my-list>li{padding:10px!important;}"

API

Exported Types

StyleMap: Record<string, CSSProperties>

Defines a map where keys are CSS selectors (string) and values are CSSProperties objects, which represent inline CSS styles in React.

Exported Functions

stringifyCSSProperties(style: CSSProperties, important?: boolean): string

Converts a single CSSProperties object to a CSS string. Automatically adds units (e.g., px) where required.

When set important argument to true, appends !important to each CSS property in the resulting string. Default is false.

stringifyStyleMap(styles: StyleMap, important?: boolean): string

Converts a StyleMap object to a string.

When set important argument to true, appends !important to each CSS property in the resulting string. Default is false.

Dependencies

• @emotion/unitless: Handles checking for CSS properties that are unitless (e.g., line-height, z-index, etc.).

Requirements

• @types/react: The package uses React's CSSProperties type for defining style objects.

Contributing

Contributions are welcome! If you have ideas or improvements, feel free to open an issue or submit a pull request.

Steps to contribute:

1. Fork the repository.
2. Create a new branch (git checkout -b feature-name).
3. Make your changes and commit (git commit -am 'Add new feature').
4. Push to the branch (git push origin feature-name).
5. Create a pull request.

Please make sure your code adheres to the project's coding standards and passes the existing tests.