postcss-json-variables

A PostCSS plugin that allows you to inject values from a JSON file into your CSS using a custom json() function. This plugin enables you to dynamically manage CSS variables by referencing JSON data, making it easier to maintain consistency across your stylesheets.

Installation

To install the plugin, use npm:

npm install postcss-json-variables --save-dev

Usage

You can use this plugin in your PostCSS configuration file. Here's an example of how to set it up:

postcss.config.js

module.exports = {
    plugins: [
        require('postcss-json-variables')({
            path: 'variables.json'
        }),
        // other PostCSS plugins
    ]
};

Example JSON File

Create a JSON file (e.g., variables.json) with your variables:

{
    "body": {
        "header": {
            "font-family": "Arial, sans-serif",
            "font-size": "16px"
        }
    }
}

Example CSS

You can now use the json() function in your CSS:

body {
    font-family: json(body[header][font-family]);
    font-size: json(body[header][font-size]);
}

API

Plugin Options

• path (String): The path to your JSON file. If not specified, it defaults to ./variables.json.

Functions

getJsonValue(jsonObject, reference)

Safely evaluates a nested JSON reference (e.g., 'body[header][font-family]') to retrieve the corresponding value from the JSON object.

• Parameters:
  • jsonObject (Object): The parsed JSON object containing variables.
  • reference (String): The direct string reference to the JSON value.
• Returns: The value from the JSON object, or undefined if the reference is invalid.

Error Handling

If the plugin fails to load or parse the specified JSON file, it will throw an error with a descriptive message. Additionally, if a referenced variable does not exist in the JSON file, the plugin will log a warning and remove the corresponding CSS declaration.

Contributing

Contributions are welcome! Please submit issues and pull requests for any enhancements or bug fixes.