Laravel 5.1 - Log in with Username or Email

App\Http\Controllers\Auth\AuthController.php

 <?php
/**
 * This snippet goes into your
 * \app\Http\Controllers\Auth\AuthController.php
 * 
 * 
 */
/**
 * Handle a login request to the application.
 *
 * @param  \Illuminate\Http\Request  $request
 * @return \Illuminate\Http\Response
 */
 
 public function postLogin(Request $request) {
        
        // $request->input('email') is from the form
        $login_type = filter_var($request->input('email'), FILTER_VALIDATE_EMAIL ) ? 'email' : 'username';

        $request->merge([ $login_type => $request->input('email')]);


        if ($login_type == 'email') {
            $this->validate($request, [
                'email'    => 'required|email', // the validation can be separate
                'password' => 'required',
            ]);
        } else {
            $this->validate($request, [
                'username' => 'required',
                'password' => 'required',
            ]);
        }

        /*
        $this->validate($request, [
            $this->loginUsername() => 'required', 'password' => 'required',
        ]);
        */
        

        // If the class is using the ThrottlesLogins trait, we can automatically throttle
        // the login attempts for this application. We'll key this by the username and
        // the IP address of the client making these requests into this application.
        $throttles = $this->isUsingThrottlesLoginsTrait();

        if ($throttles && $this->hasTooManyLoginAttempts($request)) {
            return $this->sendLockoutResponse($request);
        }

        $credentials = $request->only($login_type, 'password' );
        //$credentials = $this->getCredentials($request);

        if (Auth::attempt($credentials, $request->has('remember'))) {
            return $this->handleUserWasAuthenticated($request, $throttles);
        }

        // If the login attempt was unsuccessful we will increment the number of attempts
        // to login and redirect the user back to the login form. Of course, when this
        // user surpasses their maximum number of attempts they will get locked out.
        if ($throttles) {
            $this->incrementLoginAttempts($request);
        }
        //return $this->loginUsername();
        return redirect($this->loginPath())
            ->withInput($request->only($this->loginUsername(), 'remember'))
            ->withErrors([
                $this->loginUsername() => $this->getFailedLoginMessage(),
            ]);
    }