styled-components helps you write better CSS in React. It does so by allowing you to wrap all your component's styles into a neat, style-only component.

So, instead of this:

.wrapper{
  font-family: sans-serif;
}

.button {
  background: #2b2b2b;
  color: white;
  font-size: 24px;
  padding: 12px;
  cursor: pointer;
}

and this

import React from "react";
import './styles.css';

export default function App() {
  return (
    <div class="Wrapper">
      <button class="Button">Hello, I am a Button</button>
    </div>
  );
}

You have something like that:

import React from "react";
import styled from "styled-components";

const Wrapper = styled.div`
  font-family: sans-serif;
`;

const Button = styled.button`
  background: #2b2b2b;
  color: white;
  font-size: 24px;
  padding: 12px;
  cursor: pointer;
`;

export default function App() {
  return (
    <Wrapper>
      <Button>Hello, I am a Button</Button>
    </Wrapper>
  );
}

Which might not look like a big change. I know, I know! It looks like all that we did here was merge two files into a single one...

However, by doing so we integrated our styles into styled-components and now that the library controls our CSS it can do all kinds of cool stuff like:

• Automatic inject critical CSS
• Automatic vendor prefixing
• Theming and dynamic styling

This saves us a lot of time and allows us to focus on important stuff like adding borders to buttons and stuff like that.

Now, after this brief introduction to the wonders of styled-components, let's focus on the dynamic styling part.

Dynamic styling with styled-components

The point of dynamic styling is saving time and writing less CSS.

Imagine that you have a primary and a secondary button. They are very similar, but you want your primary button to have a flashy color so people actually click on it.

You can do that by adding a primary attribute to your <Button />...

export default function App() {
  return (
    <Wrapper>
      <Button>Hello, I am a Button</Button>
      <Button primary>Hello, I am a Primary Button</Button>
    </Wrapper>
  );
}

...and handling that new attribute on your styled component, exactly like you would with component props!

const Button = styled.button`
  background: ${props => props.primary ? "#6495ED" : "#2b2b2b"};
  color: white;
  font-size: 24px;
  padding: 12px;
  cursor: pointer;
`;

"But what if my component needs a lot of customization?"

It may happen that your buttons need to be extra flexible, while still sharing some basic styles. Maybe you need to have a primary button that also has rounded corners and a fancy box-shadow.

You can do that by applying the same logic as the earlier example. But that can get quite repetitive, look:

const Button = styled.button`
  background: ${props => props.primary ? "#6495ED" : "#2b2b2b"};
  border-radius: ${props => props.round ? "4px" : "0"};
  box-shadow: ${props => props.shadow ? "2px 2px 2px rgba(0, 0, 0, 0.5)" : "none"};
  color: white;
  font-size: 24px;
  padding: 12px;
  cursor: pointer;
`;

What you can do here instead is "lift" the props and do something like that:

const Button = styled.button(
  ({ primary, round, shadow }) => `
    background: ${primary ? "#6495ED" : "#2b2b2b"};
    border-radius: ${round ? "4px" : "0"};
    box-shadow: ${shadow ? "2px 2px 2px rgba(0, 0, 0, 0.5)" : "none"};
    color: white;
    font-size: 24px;
    padding: 12px;
    cursor: pointer;
  `
);

That way, instead of "importing" each prop on a per-line basis, you do it at the very beginning of your styles, so you can be 100% sure of what makes it dynamic!

Just keep in mind that while this technique is cool and makes your styled components look leaner, needing extensive customization might be a sign of bad abstraction.

So before adding a fourth (or fifth) dynamic style rule, make sure that you shouldn't really be creating a new styled component!

And this is it for the day. Thanks for reading!

I wrote this article (at the eleventh hour) for Hashnode Bootcamp II first assignment.

Make sure to check all the other Bootcamp articles and follow me on Twitter!