API routes in Laravel - Mini Project: Build & Apply

Building API Routes in Laravel

📖 Scenario: You are creating a simple API for a book store. The API will allow users to get a list of books and add new books.

🎯 Goal: Build API routes in Laravel to handle requests for listing all books and adding a new book.

📋 What You'll Learn

Create a route group with prefix api

Define a GET route /books that returns all books

Define a POST route /books that adds a new book

Use a controller named BookController with methods index and store

💡 Why This Matters

🌍 Real World

API routes are used to build backend services that mobile apps or frontend apps can call to get or send data.

💼 Career

Knowing how to define API routes in Laravel is essential for backend developers building RESTful services.

1

Create the initial API route group

Create a route group with prefix api in routes/api.php using Route::prefix('api')->group(function () { ... });

Laravel

// Your code here

Hint

Use Route::prefix('api')->group(function () { ... }); to start the API routes.

2

Add a GET route for listing books

Inside the api route group, add a GET route /books that uses BookController@index.

Laravel

use Illuminate\Support\Facades\Route;

Route::prefix('api')->group(function () {
    // Add GET route for /books here
});

Hint

Use Route::get('/books', [BookController::class, 'index']); inside the group.

3

Add a POST route for adding a new book

Inside the api route group, add a POST route /books that uses BookController@store.

Laravel

use Illuminate\Support\Facades\Route;

Route::prefix('api')->group(function () {
    Route::get('/books', [\App\Http\Controllers\BookController::class, 'index']);
    // Add POST route for /books here
});

Hint

Use Route::post('/books', [BookController::class, 'store']); inside the group.

4

Complete the API routes with middleware

Add the auth:sanctum middleware to the api route group to protect the routes.

Laravel

use Illuminate\Support\Facades\Route;

// Add middleware to the api route group
Route::prefix('api')->group(function () {
    Route::get('/books', [\App\Http\Controllers\BookController::class, 'index']);
    Route::post('/books', [\App\Http\Controllers\BookController::class, 'store']);
});

Hint

Add ->middleware('auth:sanctum') after prefix('api') to protect the routes.

Practice

1. What is the main purpose of defining API routes in Laravel's routes/api.php file?

easy

A. To configure middleware for user authentication

B. To define web page routes that return HTML views

C. To store database connection settings

D. To handle requests from other apps or devices and return JSON responses

Solution

1. Step 1: Understand the role of API routes

   API routes are designed to handle requests from external apps or devices, not for web pages.

2. Step 2: Identify the correct file and response type

   In Laravel, API routes are placed in routes/api.php and usually return JSON data.

3. Final Answer:

   To handle requests from other apps or devices and return JSON responses -> Option D

4. Quick Check:

   API routes = handle external requests + JSON [OK]

Hint: API routes handle external requests and return JSON [OK]

Common Mistakes:

• Confusing API routes with web routes that return HTML
• Thinking API routes are for database settings
• Assuming API routes are only for middleware

2. Which of the following is the correct syntax to define a GET API route in Laravel that returns a JSON message "Hello World"?

easy

A. Route::get('/hello', function () { return response()->json(['message' => 'Hello World']); });

B. Route::post('/hello', function () { return 'Hello World'; });

C. Route::get('/hello', function () { return view('hello'); });

D. Route::put('/hello', function () { return response('Hello World'); });

Solution

1. Step 1: Identify the HTTP verb and response type

   The question asks for a GET route that returns JSON data.

2. Step 2: Check each option's method and return

   Route::get('/hello', function () { return response()->json(['message' => 'Hello World']); }); uses GET and returns JSON with response()->json(), which is correct. Others use wrong verbs or return types.

3. Final Answer:

   Route::get('/hello', function () { return response()->json(['message' => 'Hello World']); }); -> Option A

4. Quick Check:

   GET + JSON response = Route::get('/hello', function () { return response()->json(['message' => 'Hello World']); }); [OK]

Hint: GET routes return JSON with response()->json() [OK]

Common Mistakes:

• Using POST or PUT instead of GET
• Returning plain strings instead of JSON
• Returning views in API routes

3. Given this API route in routes/api.php:

Route::post('/user', function (Illuminate\Http\Request $request) {
    return ['name' => $request->input('name'), 'age' => $request->input('age')];
});

What will be the JSON response if a POST request sends {"name": "Alice", "age": 30}?

medium

A. An error because input() is not valid

B. {"name": null, "age": null}

C. {"name": "Alice", "age": 30}

D. Empty response

Solution

1. Step 1: Understand the route and request handling

   The route accepts a POST request and reads 'name' and 'age' from the request input.

2. Step 2: Analyze the input data and response

   The POST request sends JSON with 'name' as "Alice" and 'age' as 30, so the route returns these values as JSON.

3. Final Answer:

   {"name": "Alice", "age": 30} -> Option C

4. Quick Check:

   POST input data returned as JSON = {"name": "Alice", "age": 30} [OK]

Hint: POST data accessed by input() returns JSON response [OK]

Common Mistakes:

• Assuming input() won't read JSON body
• Expecting null values if input keys missing
• Confusing GET and POST request handling

4. What is wrong with this API route definition?

Route::get('/data', function () {
    return response('Data');
});

medium

A. It should return JSON, not plain text, for API routes

B. The HTTP verb GET is not allowed in API routes

C. The route path must start with /api/

D. The closure must accept a Request parameter

Solution

1. Step 1: Check the response type for API routes

   API routes should return JSON data, but this returns plain text with response('Data').

2. Step 2: Verify HTTP verb and route path

   GET is allowed, and route paths don't need to start with /api/ because the file already scopes them.

3. Final Answer:

   It should return JSON, not plain text, for API routes -> Option A

4. Quick Check:

   API routes expect JSON responses [OK]

Hint: API routes should return JSON, not plain text [OK]

Common Mistakes:

• Thinking GET is disallowed in API routes
• Believing route paths must start with /api/
• Assuming Request parameter is mandatory

5. You want to create an API route that accepts a user ID in the URL and returns JSON with the user's name. Which of these route definitions correctly achieves this?

hard

A. Route::post('/user', function ($id) { return ['name' => 'User ' . $id]; });

B. Route::get('/user/{id}', function ($id) { return ['name' => 'User ' . $id]; });

C. Route::get('/user', function (Request $request) { return ['name' => 'User ' . $request->id]; });

D. Route::get('/user/{id}', function () { return ['name' => 'User']; });

Solution

1. Step 1: Identify route with URL parameter

   The route must accept a user ID in the URL, so it needs a parameter like {id} in the path.

2. Step 2: Check function parameters and response

   Route::get('/user/{id}', function ($id) { return ['name' => 'User ' . $id]; }); correctly uses $id parameter and returns JSON with the user's name including the ID.

3. Final Answer:

   Route::get('/user/{id}', function ($id) { return ['name' => 'User ' . $id]; }); -> Option B

4. Quick Check:

   URL param {id} passed as $id = Route::get('/user/{id}', function ($id) { return ['name' => 'User ' . $id]; }); [OK]

Hint: Use {id} in route and accept $id in closure [OK]

Common Mistakes:

• Using POST instead of GET for URL params
• Not including {id} in route path
• Not accepting $id parameter in closure