Laravel API – Showing individual file through o2m relationship

So I have two models User and File, these are connected with a one-to-many relationship.

I have sorted the API routes and controllers to index all users, show specific user and index all files uploaded by that specific user. I do not know how to write the logic that will allow this route 127.0.0.1:8001/api/2/files/1 to show the first file uploaded by the 2nd user. So/2(seconduser)/files(shows all)/1(shows only 1 file)

This is my API code:

Route::group(["prefix" => "/"], function () {
    Route::get("", [Users::class, "index"]); //show all users

    Route::group(["prefix" => "{user}"], function () {
        Route::get("", [Users::class, "show"]); //show specific user

        Route::group(["prefix" => "/files"], function () {
            Route::get("", [Files::class, "index"]); //show all files

            Route::group(["prefix" => "{file}"], function () {
                Route::get("", [Files::class, "show"]); //trying to show specific file
            });
        });
    });
});

Files Controller

<?php

namespace AppHttpControllersAPI;

use AppHttpControllersController;
use IlluminateHttpRequest;
use AppModelsUser;
use AppModelsFile;

class Files extends Controller
{
    /**
     * Display a listing of the resource.
     *
     * @return IlluminateHttpResponse
     */
    public function index(User $user)
    {
        return $user->files;    
    }


    /**
     * Display the specified resource.
     *
     * @param  int  $id
     * @return IlluminateHttpResponse
     */
    public function show(User $user, File $file)
    {
        
    }
}

Users Controller

<?php

namespace AppHttpControllersAPI;

use AppHttpControllersController;
use IlluminateHttpRequest;
use AppModelsUser;

class Users extends Controller
{
    /**
     * Display a listing of the resource.
     *
     * @return IlluminateHttpResponse
     */
    public function index()
    {
        return User::all();
    }

    /**
     * Display the specified resource.
     *
     * @param  int  $id
     * @return IlluminateHttpResponse
     */
    public function show(User $user)
    {
        return $user;
    }
}

Answer

So here’s what a typical route declaration would look like. Note the user ID is not relevant to the file request, so the files endpoint is made separate from the users endpoint.

Route::get("/users",              [Users::class, "index"]);
Route::get("/users/{user}",       [Users::class, "show"]);
Route::get("/users/{user}/files", [Files::class, "index"]);
Route::get("/files/{file}",       [Files::class, "show"]);

And then in your controller methods, you’re simply returning a list or a single item, mostly as in your original code. Note if you’re returning API data, you should explicitly return JSON.

<?php

namespace AppHttpControllersAPI;

use AppHttpControllersController;
use IlluminateHttpRequest;
use AppModelsUser;
use AppModelsFile;

class Files extends Controller
{
    /**
     * Display a listing of the resource.
     *
     * @return IlluminateHttpJsonResponse
     */
    public function index(User $user)
    {
        return response()->json($user->files);    
    }


    /**
     * Display the specified resource.
     *
     * @param  int  $id
     * @return IlluminateHttpJsonResponse
     */
    public function show(File $file)
    {
        return response()->json($file);
        // or perhaps something like this?
        return response()
            ->download($file->path, $file->name, ["Content-Type" => $file->type]);
    }
}

<?php

namespace AppHttpControllersAPI;

use AppHttpControllersController;
use IlluminateHttpRequest;
use AppModelsUser;

class Users extends Controller
{
    /**
     * Display a listing of the resource.
     *
     * @return IlluminateHttpJsonResponse
     */
    public function index()
    {
        return response()->json(User::all());
    }

    /**
     * Display the specified resource.
     *
     * @param  int  $id
     * @return IlluminateHttpJsonResponse
     */
    public function show(User $user)
    {
        return response()->json($user);
    }
}