Return JSON for exception with octoberCMS - php

Question

I have some custom routes
Route::get('/files/', [
'as' => 'read',
'uses' => 'Myname\MyPlugin\Http\Controllers\FilesController#read'
]);
Somewhere in my class I have a function to validate a path
private function getPath()
{
$path = Input::get('path');
if (!$path)
{
throw new MyException('parameter is missing. path required', 400);
}
return base_path().'/'.$path;
}
I have set a custom error handler with a JSOM but it's the error handler of OctoberCMS that render the error in HTML format.
Do you know a way to replace default error handler of OctoberCMS by a custom one ?
Thanks

Answer 1

Just found the anwser in the documentation : https://octobercms.com/docs/services/error-log#exception-handling
October provide App:error to manage Exception in your plugin.
App::error(function(MyException $exception) {
//do what you want here
}
Don't forger to create a custom Exception for your plugin. If you use the generic Exception, you'll catch all the Exceptions.

Answer 2

I am posting an alternative solution here for a custom error handler because of this questions's visibility on Google.
I had problems using App:error due to this issue on Github: https://github.com/octobercms/october/issues/3416
Rather than using October's App::error for a custom error handling, try the following:
Create a custom error handler that inherit's from October's error handler. For example, create the following class in plugins/{AUTHOR}/{PLUGIN}/classes/CustomHandler.php (assuming you are developing a plugin for OctoberCMS). Override the render method of the handler.
<?php
namespace {AUTHOR}\{PLUGIN}\Classes; //<-- CHANGE ME OBVIOUSLY FOR YOUR PLUGIN
use October\Rain\Foundation\Exception\Handler;
use Illuminate\Support\Facades\Event;
use Illuminate\Support\Facades\Response;
use Exception;
use Illuminate\Database\Eloquent\ModelNotFoundException; // As an example exception you want to handle ...
/* Custom error handler which replaces the default error handler for OctoberCMS. */
class CustomHandler extends Handler
{
/**
* Render an exception into an HTTP response.
*
* #param \Illuminate\Http\Request $request
* #param \Exception $exception
* #return \Illuminate\Http\Response
*/
public function render($request, Exception $exception)
{
/* Custom JSON response for ModelNotFoundException exceptions. */
if($exception instanceof ModelNotFoundException){
return Response::json(['error' => 'A record was not found for the resource that was requested.'], 404);
}
/* The rest of this code is just the 'default' code from OctoberCMS' error handler. */
/* The only change is the code above this comment where I handle a specific exception in a unique way.*/
/* i.e. I decided to return JSON for the error rather than an HTML error page (in debug mode). */
if (!class_exists('Event')) {
return parent::render($request, $exception);
}
$statusCode = $this->getStatusCode($exception);
$response = $this->callCustomHandlers($exception);
if (!is_null($response)) {
return Response::make($response, $statusCode);
}
if ($event = Event::fire('exception.beforeRender', [$exception, $statusCode, $request], true)) {
return Response::make($event, $statusCode);
}
return parent::render($request, $exception);
}
}
Then, in your plugin registration file Plugin.php, add a boot method with the following code:
<?php namespace {AUTHOR}\{PLUGIN};
use System\Classes\PluginBase;
use {AUTHOR}\{PLUGIN}\Classes\CustomHandler; //<-- IMPORTANT
use Illuminate\Contracts\Debug\ExceptionHandler; //<-- IMPORTANT
class Plugin extends PluginBase
{
/**
* #var array Plugin dependencies
*/
public $require = [];
public function registerComponents()
{
}
public function registerSettings()
{
}
public function boot(){
/* Replace the default error handler of OctoberCMS to return JSON format responses instead. */
/* Also, this is used in order to control the responses for certain types of errors/exceptions. */
/* We are going about it this way because App::error (as mentioned in the documentation for OctoberCMS), */
/* was not returning the response properly presumably because of a bug. Argh... */
$this->app->bind(
ExceptionHandler::class,
CustomHandler::class
);
}
}
Since, the new CustomHandler.php was added to the classes directory, the new class should already be picked up. No need for composer dump-autoload -o or changes to the composer.json.
That is it. When the ModelNotFoundException occurs, the response given to the web browser will be JSON that you wrote (from the custom error handler we created).
Relevant links:
https://blog.sarav.co/registering-custom-exception-handler-laravel-5/
https://laravel.com/docs/5.8/container#binding
https://octobercms.com/forum/post/is-it-posible-to-bring-back-the-app-directory-for-native-laravel