login.js

import React from 'react';
import { Button } from 'semantic-ui-react';

class Login extends React.Component {

    loginClicked = ()=>{
        console.log("Event clicked");
    }

    render() {
        return (
            <div>
                <Button onClick={this.loginClicked} positive>Login</Button>
            </div>
        )
    }
}

export default Login;