HOC - Functional Component

Mohammed Amir Ansari picture Mohammed Amir Ansari · Sep 9, 2019 · Viewed 13.3k times · Source

I have already created a HOC in my react app following this, and its working fine. However i was wondering if there is a way to create a HOC as functional component(With or without state)??? since the given example is a class based component.

Tried to find the same over web but couldn't get anything. Not sure if thats even possible?? Or right thing to do ever??

Any leads will be appreciated :)

Answer

onuriltan picture onuriltan · Sep 9, 2019

Definitely you can create a functional stateless component that accepts component as an input and return some other component as an output, for example;

  1. You can create a PrivateRoute component that accepts a Component as a prop value and returns some other Component depending on if user is authenticated or not.
  2. If user is not authenticated(read it from context store) then you redirect user to login page with <Redirect to='/login'/>else you return the component passed as a prop and send other props to that component <Component {...props} />

App.js

const App = () => {
  return (
      <Switch>
        <PrivateRoute exact path='/' component={Home} />
        <Route exact path='/about' component={About} />
        <Route exact path='/login' component={Login} />
        <Route exact path='/register' component={Register} />
      </Switch>
  );
}

export default App;

PrivateRoute.jsx

import React, { useContext , useEffect} from 'react';
import { Route, Redirect } from 'react-router-dom'
import AuthContext from '../../context/auth/authContext'

const PrivateRoute = ({ component: Component, ...rest }) => {
  const authContext = useContext(AuthContext)
  const { loadUser, isAuthenticated } = authContext
  useEffect(() => {
    loadUser()
    // eslint-disable-next-line
  }, [])
  if(isAuthenticated === null){
    return <></>
  }
  return (
    <Route {...rest} render={props =>
      !isAuthenticated ? (
        <Redirect to='/login'/>
      ) : (
        <Component {...props} />
      )
    }
    />
  );
};
export default PrivateRoute;

Higher Order Components does not have to be class components, their purpose is to take a Component as an input and return a component as an output according to some logic.