I don't understand Request objects in Laravel

For basic understanding what ever data your passing from your form or from get method you can access using $request simply check in your controller,

   public function index(Request $request){
     dd($request->all());
   }

You can refer to the documentation and read more on the Request Lifecycle it will clear things up for you I believe.

@MUNAZZIL - Where does the "Request $request" come from, though? I can create a function argument like that, fine, but then I have to call the function and give it an object. How does that part work out?

@UCCDEV - It comes from the Service Container a pattern called dependency injection. The whole process cannot be explained in a comment here. You can read the documentation and there is a great resource that covers all of this, the book by Matt Staufer Laravel up and running.

@NAKOV - Can you give me a practical example of it in action please? For instance, if I have the function:

    public function searchData(Request $request) {
            ....
    }

How would I create a $request for "searchData($request)" to call?

@UCCDEV - You will just have a route for it, like this:

Route::get('/search', 'YourController@searchData');

Then you can use it like this:

testurl.test?param=1

In your method the $request will be automatically filled with the data that you have passed, so $request->param will equal 1. This is done by the service container, it is a magic that happens behind the scenes. As I said this topic is huge and not easy to explain, you should read the resources that I have shared they give good examples in there. Unless you like to read the source code :)

@NAKOV - I think I see. Though in this instance, how could I use a Request object for test cases? Those don't use URL routing, if I recall correctly, they're called from the command line

@UCCDEV - They do, the same as you would in the browser, for example

$this->get('/test?param=1')->assertSuccessful();

The $request will have the correct data again.

@MUNAZZIL - I see. I've tried this now, but it gave me an empty bracket. "[]". Why would mine be empty? EDIT: Whereas if I do:

    dd($request);

I get:

    Request {#42 ▼
      #json: null
      #convertedFiles: null
      #userResolver: Closure($guard = null) {#171 ▶}
      #routeResolver: Closure() {#173 ▶}
      +attributes: ParameterBag {#44 ▶}
      +request: ParameterBag {#50 ▶}
      +query: ParameterBag {#50 ▶}
      +server: ServerBag {#46 ▶}
      +files: FileBag {#47 ▶}
      +cookies: ParameterBag {#45 ▶}
      +headers: HeaderBag {#48 ▶}
      #content: null
      #languages: null
      #charsets: null
      #encodings: null
      #acceptableContentTypes: null
      #pathInfo: "/testurl/1"
      #requestUri: "/testurl/1"
      #baseUrl: ""
      #basePath: null
      #method: "GET"
      #format: null
      #session: Store {#211 ▶}
      #locale: null
      #defaultLocale: "en"
      -isHostValid: true
      -isForwardedValid: true
      basePath: ""
      format: "html"
    }

because request()->all() returns data like $_POST and $_GET whereas dd($request); is an object. That data is stored in the object as a class property @uccdev

@RAS1212 - Thank you, ras, though then I'm still wondering why request->all() returns empty

because you have no data posted through a form or no query strings appended too the url

a quick test you can do is to add this to your route

Route::get('/test', function(){
    dd(request()->all()); 
});

and go to your-website.com/test?foo=bar

you will see there is data foo this is the $_GET stored in the Request object @uccdev

You should really study the symfony Docs

https://symfony.com/doc/current/components/http_foundation.html

This stuff is readily available and Taylor refers to symfony in the laravel Docs.

All explained and covered and documented just curious why ask again here.

But basically working with HTTP headers:

https://github.com/symfony/http-foundation/blob/master/Request.php

https://github.com/symfony/symfony/blob/master/src/Symfony/Component/HttpFoundation/Response.php

This stuff in the background is just basic php, but a lot of it, in other words they have done a lot of work to make the frameworks easier and safer.

Just think that $request as a wrapper for all the http request parameters, where it include a lot of useful functions to easier your work. if you need more details or example, you could read the documentation or inspect the code.

Enlightening, thank you. Though in my instance, I want to use a secret access token as a project-wide variable. Since it is a secret, and something the back-end should know, I don't want it passed in through the URL; it's not something that $_GET or $_POST should see. Maybe request objects aren't really the answer, if I want something like that. Any recommendations?

Why don't you study up on authentication and authorization and api access tokens.

You seem to be getting authorization confused with request.