Improving Compilation Speed with Optimized Code

Tutorial 2 of 5

1. Introduction

Welcome to this tutorial! The main goal of this tutorial is to teach you how to write efficient SASS/SCSS code that compiles quickly and reliably. By the end of this tutorial, you will be able to recognize and correct code inefficiencies that slow down the compilation process.

This tutorial assumes that you are already familiar with the basics of SASS/SCSS, and have a working environment set up for writing and compiling SASS/SCSS code.

2. Step-by-Step Guide

When writing SASS/SCSS code, it's important to ensure that the code is efficient and optimized. This not only improves the compilation speed, but also makes your codebase easier to manage and maintain. The following steps will guide you through the process.

a. Avoid Deep Nesting

Deep nesting can lead to unnecessarily large CSS files and slower compilation times. As a good practice, try to limit your nesting to 1 or 2 levels deep.

// Bad practice
nav {
  ul {
    li {
      a {
        color: blue;
      }
    }
  }
}

// Good practice
nav ul {
  li a {
    color: blue;
  }
}

b. Limit the Use of @extend

While @extend can be useful, overuse can lead to bloated CSS output and slower compilation times. Use @mixin and @include instead for reusable code.

// Bad practice
.btn {
  color: white;
  background-color: blue;
}

.btn-large {
  @extend .btn;
  font-size: 2em;
}

// Good practice
@mixin btn {
  color: white;
  background-color: blue;
}

.btn-large {
  @include btn;
  font-size: 2em;
}

c. Be Careful with Loops and Conditionals

Loops and conditionals can be expensive in terms of compilation time, especially if they're nested or complex. Use them sparingly and wisely.

3. Code Examples

Here are some practical examples:

Example 1 - Efficient Nesting

// Bad practice
header {
  nav {
    a {
      color: blue;
      &:hover {
        color: white;
        background-color: blue;
      }
    }
  }
}

// Good practice
header nav a {
  color: blue;
  &:hover {
    color: white;
    background-color: blue;
  }
}

In the first block, the nested selectors will compile into a larger CSS file, thus slowing down the compilation time. The second block, with the same styling, has a more efficient structure.

Example 2 - Using @mixin instead of @extend

// Bad practice
.button {
  display: inline-block;
  padding: 10px 20px;
  background-color: #f00;
  color: #fff;
  text-decoration: none;
}

.button-large {
  @extend .button;
  font-size: 2em;
}

// Good practice
@mixin button {
  display: inline-block;
  padding: 10px 20px;
  background-color: #f00;
  color: #fff;
  text-decoration: none;
}

.button-large {
  @include button;
  font-size: 2em;
}

In the first block, @extend creates a larger CSS output. The second block uses @mixin and @include to achieve the same result but with a smaller CSS output.

4. Summary

In this tutorial, you've learned how to write efficient SASS/SCSS code that improves compilation speed. The key points are:

Avoid deep nesting.
Limit the use of @extend.
Be careful with loops and conditionals.

To continue learning, you can explore more advanced SASS/SCSS techniques and best practices.

5. Practice Exercises

Exercise 1: Refactor the following code to avoid deep nesting:

body {
  div {
    p {
      color: blue;
    }
  }
}

Solution:

body div p {
  color: blue;
}

Exercise 2: Refactor the following code to use @mixin and @include instead of @extend:

.btn {
  color: white;
  background-color: blue;
}

.btn-large {
  @extend .btn;
  font-size: 2em;
}