Styled component with access to React component state?

Question

How can I get a styled component to render different css rules depending on the state of the React component in which it is rendered?

The below does not work:

class Container extends React.Component<ContainerProps, ContainerState> {
  constructor(props: ContainerProps) {
    super(props);
    this.state = {
      highlight: true,
      dark: false
    };
  }

  OuterWrapper = styled.div`
    display: inline-block;
    padding: 20px;
    ${this.state.dark && `
      background-color: 'gray';
    `};
  `;

    return (
      <this.OuterWrapper>
          ...
      </this.OuterWrapper>
    );

}

TypeError: Cannot read property 'dark' of undefined at new Container

Hasan Sh Hasan Sh · Accepted Answer · 2018-11-08T13:34:57

The best way to achieve that is through passing a prop to the element that you get from styled-comopnent.

// outside of the component
interface OuterWrapperProps { 
    dark: boolean; 
}

const OuterWrapper =  styled.div<OuterWrapperProps>`
    display: inline-block;
    padding: 20px;
    ${props => props.dark && css`
        background-color: 'gray';
    `};
`;

And when you render that element:

...
<OuterWrapper dark={this.state.dark}> ... </OuterWrapper>
...

And you still have the control over the theme from your state!

Doing so, helps the readability of you code, as well as following what the docs suggest.

Styled component with access to React component state?

1 Answers