cssloader

cssloader refers to a class of tools used in modern web development to process CSS files so they can be included in JavaScript applications. The most common representative is a Webpack loader that interprets CSS imports and URLs and returns CSS as a module that can be consumed by JavaScript code. This enables developers to import CSS directly in modules and have the styles applied automatically when the module is loaded.

In typical usage, a CSS loader parses CSS files, resolves dependencies such as @import statements and url() references, and then provides the resulting CSS to the bundler. Depending on configuration, the CSS can be injected into the document at runtime via style elements, or it can be extracted into separate CSS files for inclusion in the final build. When used with other loaders, it can also support features like CSS modules, which scope class names locally to avoid naming conflicts.

Common configurations involve chaining style-related loaders. For example, a chain might include a style injector (to apply styles dynamically) and the CSS loader itself. For production builds, a separate extraction step can be added to pull CSS into standalone files. Options often control module syntax, URL handling, source maps, and whether CSS modules are enabled, as well as compatibility with various preprocessing workflows.

Limitations include reliance on the build system and the need to coordinate with preprocessors (such as PostCSS, Sass, or Less) and plugins. cssloader is not a runtime CSS parser; its role is to prepare CSS for bundling and application within the JavaScript environment. See also CSS modules, Webpack, style-loader, and postcss-loader.