Laravel - 如果模型/行不存在或软删除则显示异常

Question

Lets say i have a model called "Manufacturer" with a controller which has a show method

public function show($id)
{
    $manufacturer = json_decode( $this->manufacturer->find($id) );
    return view('viewManufacturer', compact('manufacturer'));
}

And a Eloquent-repository with a find method

public function find($id)
{
    return Manufacturer::find($id)->toJson();
}

Now if a model doesn't exist or is softdeleted it gives me a fatal exception

FatalErrorException in ManufacturerRepository.php line 22:
Call to a member function toJson() on null

How do i set an exception, so instead of the default error page it shows a custom error page with something like, "Manufacturer not found".

EDIT: Well i actually tried that, but it returns an error. The above mentioned query was just for demonstration, in actual i have another model called vehicle. And Manufacturer has one to many relationship with Vehicle.

public function find($id, $columns1 = array('*'), $columns2 = array('*'))
{
    return Manufacturer::with(['vehicles' => function($q) use ($columns2){
           $q->select($columns2);
    }])->get($columns1)->find($id)->toJson();
}

So if i replace find with findOrFail it spits an error saying Call to undefined method Illuminate\Database\Eloquent\Collection::findOrFail()

Answer 1

Instead of find() method call findOrFail() - if the model is not found this method will throw ModelNotFoundException which should result in 404 page in your application.

UPDATE:

In your second example replace:

return Manufacturer::with(['vehicles' => function($q) use ($columns2){
  $q->select($columns2);
}])->get($columns1)->find($id)->toJson();

with

return Manufacturer::with(['vehicles' => function($q) use ($columns2){
  $q->select($columns2);
}])->findOrFail($id, $columns1)->toJson();