Global handling of Laravel exceptions to better support AJAX requests.

laravel-global-exception-handler.php

<?php namespace App\Exceptions;

use Log;
use Mail;
use Config;
use Exception;
use Illuminate\Auth\Access\UnauthorizedException;
use Illuminate\Session\TokenMismatchException;
use Illuminate\Foundation\Exceptions\Handler as ExceptionHandler;

class Handler extends ExceptionHandler {

    /**
     * Report or log an exception.
     *
     * This is a great spot to send exceptions to Sentry, Bugsnag, etc.
     *
     * @param  \Exception  $e
     * @return mixed
     */
    public function report(Exception $e)
    {
        return parent::report($e);
    }

    /**
     * Render an exception into an HTTP response.
     * 
     * Note that UnauthorizedException is Laravel 5.4.
     *
     * @param  \Illuminate\Http\Request     $request
     * @param  \Exception                   $e
     * @return \Illuminate\Http\Response
     */
    public function render($request, Exception $e)
    {
        if ($this->isHttpException($e)) {
            return $this->renderHttpException($e);
        }

        $msg = null;
        
        if ($e instanceof TokenMismatchException) {
            $msg = 'Your session token had expired. Please try again.';
        } else if ($e instanceof UnauthorizedException) {
            $msg = 'You are not authorized to perform the previous action.';
        }
        
        if (!is_null($msg)) {
            if ($request->ajax()) {
                // return an appropriate response message
                return response()->json(['error' => $msg], 403);
            } else {
                // redirect back to the page that caused the error
                return redirect()
                    ->back()
                    ->withErrors(['error' => $msg])
                    ->withInput();
            }
        }

        return parent::render($request, $e);
    }
    
}