[SOLVED] How can I use tailwind-css to style the active state of the Navlink(react-router-dom)?

How can I use tailwind-css to style the active state of the Navlink(react-router-dom)?

I am trying to use a template literal for the className of the Navlink but it does not work.

This is current code:

className={`px-2 py-2.5 hover:bg-cprimary-300 hover:text-csecond-100 rounded-md transition ${({ isActive }) => isActive ? "bg-red-500" : "bg-black-500"}`}

I tried using only the active part to check if anything else is messing with it but it still does not work.

className={`${({ isActive }) => isActive ? "bg-red-500" : "bg-blue-500"}`}

Is there something wrong with the way I am using the template literal?

It works when I use this:

className={({ isActive }) => isActive ? "bg-red-500" : "bg-blue-500"}

Solution

The className prop takes either a string or a function callback that is passed an isActive prop and returns a string or undefined.

See NavLink

declare function NavLink(
  props: NavLinkProps
): React.ReactElement;

interface NavLinkProps
  extends Omit<
    LinkProps,
    "className" | "style" | "children"
  > {
  caseSensitive?: boolean;
  children?:
    | React.ReactNode
    | ((props: { isActive: boolean }) => React.ReactNode);
  className?:
    | string
    | ((props: { isActive: boolean; }) => string | undefined); // <--
  end?: boolean;
  style?:
    | React.CSSProperties
    | ((props: { isActive: boolean; }) => React.CSSProperties);
}

Use the callback function to accept the isActive prop and return a string containing the CSS classes you want to be applied.

className={({ isActive }) => [
    "px-2 py-2.5",
    "hover:bg-cprimary-300 hover:text-csecond-100",
    "rounded-md transition",
    isActive ? "bg-red-500" : "bg-black-500"
  ].join(" ")
}