[React] Create component variations in React with styled-components and "extend"

In this lesson, we extend the styles of a base button component to create multiple variations of buttons, using "extend". We can then modify the base styles in one place, and have all button types updated.

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

const Button = styled.button`
  background: ${props => props.theme.base};
  color: white;
  font-size: 1rem;
  padding: .75rem 2rem;
  box-shadow:  3px 5px rgba(, , , 0.1);
  cursor: pointer;
  border: none;
  border-radius: 4px;
  margin: .5rem;
  transition: all .1s;
  &:hover {
    transform: translateY(1px);
    box-shadow:  2px 3px rgba(, , , 0.15);
  }
`;

const ButtonDanger = Button.extend`background: ${props => props.theme.danger};`;
const ButtonGradient = Button.extend`
  background: ${props => props.theme.gradient};
`;

/* ============================== */
/* ===== the main component ===== */
/* ============================== */
const App = () =>
  <div>
    <Button>Basic button</Button>
    <ButtonDanger>Watch out now!</ButtonDanger>
    <ButtonGradient>Gradient Button!</ButtonGradient>
  </div>;

export default App;

theme:

import React from "react";
import ReactDOM from "react-dom";
import App from "./App";

import { ThemeProvider, injectGlobal } from "styled-components";

injectGlobal`
  body {
    margin: ;
    padding: 2rem;
    font-family: -apple-system,
      BlinkMacSystemFont,
      "Segoe UI",
      Roboto,
      Helvetica,
      Arial,
      sans-serif,
      "Apple Color Emoji",
      "Segoe UI Emoji",
      "Segoe UI Symbol";
  }
`;

const theme = {
  base: "#a04ed9",
  danger: "tomato",
  gradient: `background-color: #00DBDE; background-image: linear-gradient(225deg, #00DBDE %, #FC00FF %);`
};

ReactDOM.render(
  <ThemeProvider theme={theme}>
    <App />
  </ThemeProvider>,
  document.getElementById("root")
);