Fela VS styled-jsx

[Fela](https://fela.js.org/) and [Griffel](https://github.com/microsoft/griffel) are also not bad choice.

Speaking of libraries and implementation. I implemented themes for white label (and not only) on UI via styles as a function of state on UI. I used https://fela.js.org/ for this. So basically, when a React app initializes, a part of the state is initialized (via identity of a user, like email they log in or meta info, or additional API call, or via URL) with a value telling if it's a partner X vs partner Y vs your own brand. Then the styles that have colours, backgrounds, borders, box-shadows, fonts are applied by fela. So I created a bunch of styled components like buttons, toggles, styled divs, etc and each of them has access to that piece of state holding the UI theme, and depending on that theme, it will apply CSS classes in the runtime. You can use the same mechanism to implement multiple themes for your own brand (not just light/dark modes). The only thing you need to manually code is a JSON spec for themes like:

You'd rather use this over tailwind? Na...

styled-jsx -> A library with a lot of similar features like styled-components. Has some extra features here and there.

This isn't a new idea. CSS in JS is obviously a thing, but that usually implies having component code with CSS right alongside it in some sort of JS based syntax. There's also JSS which is a library for writing CSS with JS.

The CSS we'll use for the Gantt chart is included in the starter code. We've used Styled JSX, which comes with Next.js, to write scoped-styled components. There are some global styles in styles/globals.js. These global styles are added to our app in the Layout component in the components folder. The entire app is wrapped in this Layout component in the _app.js file, which is in the pages folder.

Styled JSX is what we're using at work right now, since we're using Next.js and it comes with this out of the box. We're actually using both SCSS modules for static styles and Styled JSX for dynamic styles. It's been great so far.

// schema.json { "$schema": "http://json-schema.org/schema", "cli": "nx", "$id": "ReactLibrary", "title": "", "type": "object", "properties": { "name": { "type": "string", "description": "Library name", "$default": { "$source": "argv", "index": 0 }, "x-prompt": "What name would you like to use for the library?", "pattern": "^[a-zA-Z].*$" }, "directory": { "type": "string", "description": "A directory where the lib is placed.", "alias": "dir" }, "domain": { "description": "Domain where this library belongs.", "type": "string", "default": "none", "alias": "dom", "x-prompt": { "message": "Which domain this library belongs?", "type": "list", "items": [ { "value": "web", "label": "Web" }, { "value": "common", "label": "Common" } ] } }, "scope": { "type": "string", "description": "A scope for the lib.", "alias": "sc" }, "type": { "description": "Library type", "type": "string", "alias": "t", "x-prompt": { "message": "Select library type?", "type": "list", "items": [ { "value": "data", "label": "Data" }, { "value": "model", "label": "Model" }, { "value": "util", "label": "Util" }, { "value": "feature", "label": "Feature" }, { "value": "ui", "label": "Ui" } ] } }, "style": { "description": "The file extension to be used for style files.", "type": "string", "default": "none", "alias": "s", "x-prompt": { "message": "Which stylesheet format would you like to use?", "type": "list", "items": [ { "value": "css", "label": "CSS" }, { "value": "scss", "label": "SASS(.scss) [ http://sass-lang.com ]" }, { "value": "styl", "label": "Stylus(.styl) [ http://stylus-lang.com ]" }, { "value": "less", "label": "LESS [ http://lesscss.org ]" }, { "value": "styled-components", "label": "styled-components [ https://styled-components.com ]" }, { "value": "@emotion/styled", "label": "emotion [ https://emotion.sh ]" }, { "value": "styled-jsx", "label": "styled-jsx [ https://www.npmjs.com/package/styled-jsx ]" }, { "value": "none", "label": "None" } ] } }, "linter": { "description": "The tool to use for running lint checks.", "type": "string", "enum": ["eslint", "tslint"], "default": "eslint" }, "unitTestRunner": { "type": "string", "enum": ["jest", "none"], "description": "Test runner to use for unit tests.", "default": "jest" }, "skipFormat": { "description": "Skip formatting files.", "type": "boolean", "default": false }, "skipTsConfig": { "type": "boolean", "default": false, "description": "Do not update `tsconfig.json` for development experience." }, "pascalCaseFiles": { "type": "boolean", "description": "Use pascal case component file name (e.g. `App.tsx`).", "alias": "P", "default": false }, "routing": { "type": "boolean", "description": "Generate library with routes." }, "appProject": { "type": "string", "description": "The application project to add the library route to.", "alias": "a" }, "publishable": { "type": "boolean", "description": "Create a publishable library." }, "buildable": { "type": "boolean", "default": false, "description": "Generate a buildable library." }, "importPath": { "type": "string", "description": "The library name used to import it, like `@myorg/my-awesome-lib`." }, "component": { "type": "boolean", "description": "Generate a default component.", "default": true }, "js": { "type": "boolean", "description": "Generate JavaScript files rather than TypeScript files.", "default": false }, "globalCss": { "type": "boolean", "description": "When `true`, the stylesheet is generated using global CSS instead of CSS modules (e.g. file is `*.css` rather than `*.module.css`).", "default": false }, "strict": { "type": "boolean", "description": "Whether to enable tsconfig strict mode or not.", "default": true }, "setParserOptionsProject": { "type": "boolean", "description": "Whether or not to configure the ESLint `parserOptions.project` option. We do not do this by default for lint performance reasons.", "default": false }, "standaloneConfig": { "description": "Split the project configuration into `/project.json` rather than including it inside `workspace.json`.", "type": "boolean" }, "compiler": { "type": "string", "enum": ["babel", "swc"], "default": "swc", "description": "Which compiler to use." } }, "required": ["name", "type", "scope", "domain"] }

The previous three methods covered the best styling options if you prefer Utility CSS. But perhaps you are more of a CSS-in-JS kind of person. In which case, Styled-JSX might be up your alley.