如何为样式组件中的值传递变量/文字？

Question

I always use props as it's the basic way for managing different use cases, but I'm trying to change border color during the focus state of a styled input (is it possible to assign props to a focus state?).

I'm familiar with using props but even within the styled component, I'm not able to assign to a variable. i can't say {props => props.focused ? accentCol : null} {props => props.focused ? accentCol : null} . The only way I've been able to assign variables has been through inline styles. However, afaik there's no way to access focus state through inline styles :/

const accentCol = `{some redux function which retrieves different colors in different scenarios`

const styledInput = styled.input`
  background: #181a1a;
  border: 1px solid rgba(255, 255, 255, 0.4);
  &::placeholder {
  }
  &:focus {
    outline: none !important;
    border: solid 2px accentCol !important;
  }
`

how do I assign border color to a variable?

Answer 1

interface IProps {
  focus: string,
}

const variantsfocus = {
  primary: 'solid 2px accentCol',
};

const StyledInput = styled.input<IProps>`
  background: #181a1a;
  border: 1px solid rgba(255, 255, 255, 0.4);
  &::placeholder {
  }
  &:focus {
    outline: none !important;
    border: ${props => variantsfocus[props.focus]};
  }
`

I hope this would be helpful, you have to pass the prop in the component like

<StyledInput focus="primary" />

Answer 2

Following the docs explanation:

const StyledInput = styled.input`
  &:focus {
    outline: none;
    border: solid 2px ${(props) => props.focusBorder};
  }
`;

function App() {
  return (
    <>
      <StyledInput focusBorder="red" />
      <StyledInput focusBorder="blue" />
    </>
  );
}

https://codesandbox.io/s/styled-focus-etf4pd