Laravel - multiple forms/tables - carry over variable in URL to fill table column - laravel-5.7

Question

I am quite new to coding and to Laravel (using 5.7). I understood how to create a basic one-page form to populate a table in a database, including relashionship and authentication but I have difficulties reaching the next level.
The app I want to design will have multiple forms and tables and I can't figure out how to link info collected from the first form to the following one.
Let's consider a Database with:
- a Clients table (populated thru form page A) ex: one field is a client_id field.
- a Products table (populated thru form page B)
- (ultimately they will be more)
When the user (e.g. an employee of a compagny analyzing clients behavior) is done filling the form page A (URL: /clients, GET method: Clientcontroller#create, view clients.create.blade.php), he/she click Next.
My idea is that the Next button should:
- submit information to the Client table (POST method: Clientscontroller#store)
- and redirect the user to the page B of the form, carrying over the client_id in the URL (URL: /products/{client_id}/create, GET method: Productscontroller#create, view products.create.blade.php).
In the Product table, I have a client_id column and I have a one to many relashionship between the Clients and Products model.
Upon submission of form B, I would like to retrieve the {client_id} from URL to fill the client_id column of the Product table but I am stuck here. I would appreciate pieces of guidance and advices. For simplification during the learning process, I consider that Clients only buy one product.
THE MAIN QUESTION IS:
- How to retrieve the {client_id} parameter from the URL of the products.create.blade.php view to inject it onto the client view (already tried a lot of thing from answer to similar questions in stackoverflow)
ALSO:
- Am I using the right approach? Any suggestions/advices?
EXTRA QUESTION a bit out of the scope:
- Any hint on how implement add/remove fields for products?
WEB ROUTES FILE:
> <?php
> Route::get('/', 'PagesController#welcome')->name('welcome');
> Auth::routes();
> //ROUTES FOR CLIENT
> Route::resource('clients','ClientsController');
> //ROUTES FOR PRODUCT (please note the {client_id} parameter)
> Route::get('/products/{client_id}/create', 'ProductsController#create')->name('products.create');
> Route::post('/products/{client_id}', 'ProductsController#store')->name('products.store');
> //not sure if it should be Route::post('/products', 'ProductsController#store')->name('products.store');
CLIENTS CONTROLLER:
<?php
namespace App\Http\Controllers;
use Illuminate\Http\Request;
use App\Client; //THIS IS THE CLIENT MODEL
use App\User; ////THIS IS THE USER MODEL
class ClientsController extends Controller
{
AUTH
public function __construct()
{
$this->middleware('auth');
}
//INDEX (CLIENT)
public function index()
{
//my code here
}
//CREATE (CLIENT)
public function create()
{
$datas=[
'controllermethod' => 'ClientsController#store',
'client_id_field' => [
'input_type_l' => 'textinput',
'input_name_l' => 'client_id', //this what i am carrying over in URL
'input_label_l' => 'Client ID :',
'input_placeholder_l' => 'XXXXX',
'input_default_l' => ''
],
'client_info_1_field' => [
'input_type_l' => 'textinput',
'input_name_l' => 'client_info_1'
'input_label_l' => 'Client Info 1 :',
'input_placeholder_l' => 'XXXXX',
'input_default_l' => ''
],
'client_info_2_field' => [
'input_type_l' => 'textinput',
'input_name_l' => 'client_info_2'
'input_label_l' => 'Client Info 2 :',
'input_placeholder_l' => 'XXXXX',
'input_default_l' => ''
]
],
return view ('clients.create')->with($datas);
}
//STORE (CLIENT)
public function store(Request $request)
{
$this->validate($request, [
'client_id' => 'required',
]);
$client = new Client;
$client->client_id = $request->input('client_id');
$client->client_info_1 = $request->input('client_info_1');
$client->client_info_2 = $request->input('client_info_2');
$client->user_id = auth()->user()->id; //one to many relashionship betw user/client models
$client->save();
//
//this is how I inject the {client_id} parameter onto the URL
//this works, the products.create view is displayed, the URL contain the client_id from formA entered by the user
$client_id = $request->client_id;
return redirect("/products/$client_id/create")->with('client_id', $client_id)
->with('success','New client record created');
//SHOW/DESTROY/EDIT/UPDATE FUNCTIONS....all this work
PRODUCTS CONTROLLER = THAT's WERE I AM STUCK + NOT SURE IF IT's THE RIGHT APPROACH
<?php
namespace App\Http\Controllers;
use Illuminate\Http\Request;
//note sure if I need that
//use Illuminate\Routing\Route;
use App\Product;
use App\Client;
use App\User;
class ProductsController extends Controller
{
//AUTH
public function __construct()
{
$this->middleware('auth');
}
//INDEX (PRODUCT)
public function index()
{
//no code so far
}
//INDEX (PRODUCT)
public function create()
{
$datas=[
'controllermethod' => 'ProductsController#store',
//planning of having dynamic add/remove products fields but let's keep it simple (1 client -> 1 product)
'product_id_field' => [
'input_type_l' => 'textinput',
'input_name_l' => 'product_id',
'input_label_l' => 'Date of cancer diagnosis :',
'input_default_l' => ''
],
'product_info_1_field' => [
'input_type_l' => 'textinput',
'input_name_l' => 'product_info_1'
'input_label_l' => 'Product Info 1 :',
'input_placeholder_l' => 'XXXXX',
'input_default_l' => ''
],
'product_info_2_field' => [
'input_type_l' => 'textinput',
'input_name_l' => 'product_info_2'
'input_label_l' => 'Product Info 2 :',
'input_placeholder_l' => 'XXXXX',
'input_default_l' => ''
]
],
//Below, I am not sure I should do that
return view ('products.create')->with($datas);
}
// STORE (PRODUCT) = THAT's WHERE I AM STUCK
// everything works except that the client_id column in the products table stays empty or filled with crap
public function store(Request $request)
{
//NOT SURE WHAT TO DO HERE TO RETRIEVE THE {client_id} from the "/products/$client_id/create" ...
//TO FURTHER INJECT IT AS A VALUE IN THE client_id COLUMN OF THE PRODUCT TABLE
//I KNOW IT's CRAP, but I TRIED THINGS ALONG THOSE LINES:
//return $client_id;
//$client_id = request()->route()->paremeters('client_id');
//$client_id = request()->route('client_id');
//$client_id = $request->client_id;
//$client_id = url('client_id');
$product = new Diagnosis;
$product->product_id = $request->input('product_id');
$product->product_info_1 = $request->input('product_info_1');
$product->product_info_2 = $request->input('product_info_2');
$product->user_id = auth()->user()->id;
//I KNOW IT's CRAP, but I TRIED THINGS ALONG THOSE LINES:
//$diagnosis->client_id = $client_id; //NB: if I write $diagnosis->client_id = 'whatever'; it works
$diagnosis->save();
//redirect to client.index view
return redirect('/clients')->with('success','New patient diagnosis (-es) created');
}

Answer 1

our solution will start by looking to this route :
Route::get('/products/{client_id}/create','ProductsController#create')->name('products.create');
this is the route that contains your client_id that we want to retrieve, and since this value is on the link, we can use the Request object to access to it!
like i said, the $request object already contains the client_id value, so what we need is to retrieve it and send it as a parameter to the view using the with function, so basically your ProductsController#create will be like this :
public function create(Request $request)
{
// all your code ...
return view ('products.create')->with("data",$datas)->with("client_id",$request->client_id);
}
so now, we access this value from our view right ? the idea is to add this value as a hidden input on the product form! ( something like this )
<form>
<!-- other inputs .... -->
<input type="hidden" value="{{$client_id}}" name="client_id" />
</form>
after submitting the form, this route will be called :
Route::post('/products/{client_id}', 'ProductsController#store')->name('products.store');
since the client_id will be sent through the form and not using the link, it would be better if you change your route to
Route::post('/products', 'ProductsController#store')->name('products.store');
now, we can have access to our value on the store function just by using
$client_id = $request->input('client_id')

Answer 2

Here is an alternative solution which works too:
ROUTES:
Route::get('/products/{client_id}/create', 'ProductsController#create')-name('products.create');
Route::post('/products', 'ProductsController#store')->name('products.store');
PRODUCTS CONTROLLER CREATE FUNCTION:
public function create() //keep as in the original question
{
// all your code ...
return view ('products.create')->with("data",$datas)->with("client_id",$request->client_id);
}
IN THE VIEW:
<form>
<!-- other inputs .... -->
<input type="hidden" value="{{Request::segment(2)}}" name="client_id" /> //access the URL segmment 2 which correspond to the client_id
</form>
IN THE PRODUCTS CONTROLLER STORE FUNCTION:
$client_id = $request->input('client_id')
It would have be nice to use the Request::segment(2) directly in the store function like this but this triggers a "Non-static method Illuminate\Http\Request::segment() should not be called statically" error that I have not been able to resolve. I don't need an answer to that, however an hint would be appreciated anyway. Maybe I'll post a new question if this has not been resolved already.