Laravel 5 HTTP/Requests - pass url parameter to the rules() method

Question

I'm trying to create a set of rules under the new \HTTP\Requests\UpdateArticle class for the slug field, which needs to have unique filter applied, but only when the id is not equal the url parameter of the route name article/{article}.

What I got so far is:

public function rules()
{
    return [
        'title' => 'required|min:3',
        'excerpt' => 'required',
        'body' => 'required',
        'slug' => 'required|unique:articles,slug,?',
        'active' => 'required',
        'published_at' => 'required|date'
    ];

}

I need to replace the question mark at the end of the unique filter for slug field with the id from the url, but don't know how to obtain it.

Answer 1

You can retrieve route parameters by name with input():

$id = Route::input('id');
return [
    // ...
    'slug' => 'required|unique:articles,id,' . $id,
    // ...
];

It's right there in the docs (scroll down to Accessing A Route Parameter Value)

Answer 2

To get URL parameters from the URL:

$this->route('id');

A great discussion on this were also asked here.