Document how to use mixins
How to build components that leverage them
How to build styles for use in those components
What our exporter updates and doesn’t update
How to Use Mixins
Mixins in Sass are a powerful way to create reusable styles, keeping your stylesheets modular and reducing duplication. They allow you to encapsulate a group of CSS properties and apply them across multiple selectors.
Best Practices
Avoid Overuse: While mixins are useful, excessive use, especially without parameters, can lead to bloated CSS due to code duplication. Use mixins judiciously to balance maintainability and performance.
Utilize Placeholders for Repeated Styles: For styles that don't require parameters and are reused frequently, consider using placeholders (
%
) with the@extend
directive. This approach avoids duplication in the compiled CSS.Organize Mixins Logically: Store mixins in a dedicated file (e.g.,
_source.sass
) and import them into your main stylesheet. This organization enhances code readability and maintainability.
Defining a Mixin
A mixin is declared using the @mixin
keyword, followed by a name and an optional parameter list.
// src/sass/_source.sass @mixin button-style($bg-color, $text-color) { background-color: $bg-color; color: $text-color; padding: 10px 20px; border: none; border-radius: 5px; font-weight: bold; text-transform: uppercase; cursor: pointer; transition: background-color 0.3s; &:hover { background-color: darken($bg-color, 10%); } }
Using a Mixin
To apply the mixin, use the @include
directive:
// src/sass/components/_buttons.sass @import '../mixins'; .button-primary { @include button-style(#3498db, #ffffff); } .button-secondary { @include button-style(#2ecc71, #ffffff); }
This keeps the styles flexible, allowing color customization while reusing common button properties.
Install Necessary Dependencies
First, ensure you have Node.js and npm installed. Then, install the required packages:
Sass: A preprocessor scripting language that is interpreted or compiled into CSS.
Browser-Sync: A live-reloading server for development.
Concurrently: Allows running multiple npm scripts simultaneously.
Nodemon: Automatically restarts the server on file changes.
Rimraf: A cross-platform tool to remove files and directories.
npm install sass browser-sync concurrently nodemon rimraf --save-dev
Configure package.json
Scripts
In your package.json
file, define scripts to handle various tasks:
{ "scripts": { "clean": "rimraf dist", "build": "npm run clean && sass src/sass/custom.sass:dist/prod.css --style compressed && cp src/index.html dist/ && cp src/404.html dist/", "serve": "browser-sync start --server dist --files 'dist/**/*' --no-notify", "start": "npm run build && npm run serve", "watch:sass": "sass --watch src/sass/custom.sass:dist/prod.css --style compressed", "watch:files": "nodemon --watch src --ext html --exec \"cp src/*.html dist/\"", "dev": "npm run clean && npm run build && concurrently \"npm run watch:sass\" \"npm run watch:files\" \"npm run serve\"" } }
Script Breakdown:
clean
: Removes thedist
directory to ensure a fresh build.build
: Cleans thedist
directory, compiles Sass to CSS with compression, and copies HTML files todist
.serve
: Starts a development server with live reloading using Browser-Sync.start
: Runs thebuild
script and then starts the server.watch:sass
: Watches for changes in Sass files and recompiles them automatically.watch:files
: Watches for changes in HTML files and copies them todist
upon modification.dev
: Cleans thedist
directory, builds the project, and runswatch:sass
,watch:files
, andserve
concurrently for development.
Running the Scripts
Development Mode: For active development with live reloading, run:
npm run dev
This command watches for changes in your Sass and HTML files, recompiles them, and reloads the browser automatically.
Production Build: To create a production-ready build, run:
npm run build
This command compiles and compresses your Sass files and prepares your HTML files in the dist
directory for deployment.
Additional Resources:
How to Build Components That Leverage Mixins
When structuring your components, it’s best to follow a modular approach, keeping mixins in a separate file and applying them where needed.
Example: Building a Card Component
Define a Card Mixin
// src/sass/_source.sass @mixin card-style($border-radius: 8px, $shadow: 0px 4px 6px rgba(0, 0, 0, 0.1)) { background-color: #fff; border-radius: $border-radius; box-shadow: $shadow; padding: 16px; transition: box-shadow 0.3s; &:hover { box-shadow: 0px 6px 10px rgba(0, 0, 0, 0.15); } }
Apply the Mixin to a Card Component
// src/sass/components/_card.sass @import '../mixins'; .card { @include card-style; width: 300px; }
Use the Component in HTML
<div class="card"> <h2>Card Title</h2> <p>This is an example card with reusable styles.</p> </div>
Now, every .card
will inherit the default styling, but it remains customizable via parameters.
How to Build Styles for Use in Components
To maintain consistency across your project, you should:
Define global variables for colors, spacing, and typography.
Use mixins for reusable styles.
Structure components with BEM methodology (
Block__Element--Modifier
).
Example: Styling an Input Field
Define Input Styles Using a Mixin
// src/sass/_source.sass @mixin input-style($border-color: #ccc, $focus-color: #3498db) { border: 1px solid $border-color; padding: 8px; border-radius: 4px; outline: none; transition: border-color 0.3s; &:focus { border-color: $focus-color; } }
Apply the Mixin in an Input Component
// src/sass/components/_input.sass @import '../mixins'; .input { @include input-style; width: 100%; font-size: 16px; }
Use It in HTML
<input type="text" class="input" placeholder="Enter text here">
Now, all input fields share a consistent style.
What Our Exporter Supports
What It Updates
Design Tokens:
Colors
Typography (font, size, weight)
Spacing (margins, paddings)
Border radius
Shadows
Mixin Definitions:
If a design system uses predefined patterns, Eggstractor can generate mixins for reuse.Basic Componet Styles:
Extracted from Figma layers when structured consistently.
What It Doesn’t Update
Component-Specific Custom Styles:
If a button or input has hardcoded styles not tied to design tokens, they won’t be updated.
Example:
border: 2px solid red;
won’t be automatically converted into a token.
Third-Party Libraries:
Styles from external frameworks like Bootstrap or Material UI won’t be extracted.
Custom CSS written outside Sass won’t be recognized.
Complex Layout Styles:
Grid/Flexbox rules won’t always be mapped unless explicitly defined in Figma.
Nested components might not be fully converted.
Additional Resources