Creating middleware in Laravel - Performance Optimization Steps

Performance: Creating middleware

MEDIUM IMPACT

Middleware affects request processing speed and response time by adding extra steps before or after controller actions.

Adding authentication checks to requests

Laravel

<?php
namespace App\Http\Middleware;
use Closure;
class CheckAuth {
    public function handle($request, Closure $next) {
        // Use cached user info or lightweight check
        if (!$request->user()?->is_active) {
            return redirect('login');
        }
        return $next($request);
    }
}

Avoids heavy queries by using cached or already loaded user data, speeding up middleware execution.

📈 Performance GainReduces blocking time to under 5ms per request

Adding authentication checks to requests

Laravel

<?php
namespace App\Http\Middleware;
use Closure;
class CheckAuth {
    public function handle($request, Closure $next) {
        // Heavy database query inside middleware
        $user = \DB::table('users')->where('id', $request->user()->id)->first();
        if (!$user || !$user->is_active) {
            return redirect('login');
        }
        return $next($request);
    }
}

Running a heavy database query on every request in middleware causes delays and blocks request processing.

📉 Performance CostBlocks request processing for 50-100ms per request depending on DB speed

Performance Comparison

Pattern	DOM Operations	Reflows	Paint Cost	Verdict
Heavy DB query in middleware	0 (server-side)	0	0	[X] Bad
Lightweight cached check in middleware	0 (server-side)	0	0	[OK] Good

Rendering Pipeline

Middleware runs during the server request lifecycle before the response is sent. It affects server response time, which impacts how fast the browser receives content.

→Server Request Processing

→Response Generation

⚠️ BottleneckHeavy synchronous operations inside middleware delay response generation.

Core Web Vital Affected

INP

Middleware affects request processing speed and response time by adding extra steps before or after controller actions.

Optimization Tips

1Avoid heavy synchronous operations inside middleware.

2Use cached data instead of repeated database queries.

3Keep middleware logic minimal to speed up server response.

Performance Quiz - 3 Questions

What is the main performance risk of adding heavy database queries inside Laravel middleware?

A It increases CSS paint cost.

B It causes browser layout shifts.

C It delays server response, increasing user wait time.

D It reduces JavaScript execution speed.

DevTools: Network

How to check: Open DevTools > Network tab > Reload page > Look at Time column for server response time delays.

What to look for: Long server response times indicate slow middleware or backend processing.

Practice

1. What is the primary purpose of middleware in Laravel?

easy

A. To define routes for the application

B. To filter and modify HTTP requests before they reach the controller

C. To create database migrations automatically

D. To generate views for the user interface

Solution

1. Step 1: Understand middleware role

   Middleware acts as a filter that processes HTTP requests before they reach the controller or after the response leaves the controller.

2. Step 2: Identify correct purpose

   Among the options, only filtering and modifying HTTP requests matches middleware's role.

3. Final Answer:

   To filter and modify HTTP requests before they reach the controller -> Option B

4. Quick Check:

   Middleware filters requests [OK]

Hint: Middleware filters requests before controllers [OK]

Common Mistakes:

• Confusing middleware with routing
• Thinking middleware creates database migrations
• Assuming middleware generates views

2. Which command correctly creates a new middleware named CheckAge in Laravel?

easy

A. php artisan make:middleware CheckAge

B. php artisan create:middleware CheckAge

C. php artisan middleware:create CheckAge

D. php artisan generate:middleware CheckAge

Solution

1. Step 1: Recall Laravel artisan command for middleware

   The correct command to create middleware is php artisan make:middleware Name.

2. Step 2: Match the command with options

   Only php artisan make:middleware CheckAge uses the exact correct syntax.

3. Final Answer:

   php artisan make:middleware CheckAge -> Option A

4. Quick Check:

   Use 'make:middleware' to create middleware [OK]

Hint: Use 'make:middleware' with artisan to create middleware [OK]

Common Mistakes:

• Using 'create:middleware' instead of 'make:middleware'
• Mixing command order or keywords
• Forgetting to specify middleware name

3. Given this middleware handle method, what will happen if the user is not authenticated?

public function handle($request, Closure $next) {
    if (!auth()->check()) {
        return redirect('login');
    }
    return $next($request);
}

medium

A. The request proceeds to the next middleware or controller

B. The request is blocked with a 403 Forbidden response

C. An error is thrown because of missing return

D. The user is redirected to the login page

Solution

1. Step 1: Analyze the authentication check

   The code checks if the user is not authenticated using !auth()->check().

2. Step 2: Understand the redirect action

   If not authenticated, it returns a redirect response to 'login', stopping further request processing.

3. Final Answer:

   The user is redirected to the login page -> Option D

4. Quick Check:

   Unauthenticated users get redirected [OK]

Hint: Redirect happens if auth check fails [OK]

Common Mistakes:

• Assuming request proceeds despite failed auth
• Thinking an error is thrown
• Confusing redirect with 403 response

4. Identify the error in this middleware handle method:

public function handle($request, Closure $next) {
    if ($request->user()->role !== 'admin') {
        abort(403, 'Unauthorized');
    }
}

medium

A. No error, this middleware is correct

B. Incorrect method name, should be handleRequest

C. Missing return statement for $next middleware call

D. Using abort() is not allowed in middleware

Solution

1. Step 1: Check middleware handle method structure

   Middleware must return either a response or call $next($request) to continue the request.

2. Step 2: Identify missing return

   This code aborts if role is not admin but does not return $next($request) if the user is admin, causing no response to be returned.

3. Final Answer:

   Missing return statement for $next middleware call -> Option C

4. Quick Check:

   Always return $next($request) to continue [OK]

Hint: Always return $next($request) in middleware [OK]

Common Mistakes:

• Forgetting to return $next($request)
• Thinking abort() is disallowed
• Renaming handle method incorrectly

5. You want to create middleware that blocks requests with a query parameter blocked=true by aborting with a 403 Forbidden response. Which handle method implementation correctly achieves this?

hard

A. public function handle($request, Closure $next) {
if ($request->query('blocked') === 'true') {
abort(403, 'Access denied');
}
return $next($request);
}

B. public function handle($request, Closure $next) {
if ($request->input('blocked') == true) {
return redirect('home');
}
return $next($request);
}

C. public function handle($request, Closure $next) {
if ($request->blocked === true) {
abort(404);
}
return $next($request);
}

D. public function handle($request, Closure $next) {
if ($request->has('blocked')) {
return response('Blocked', 401);
}
return $next($request);
}

Solution

1. Step 1: Check how to read query parameters

   Use $request->query('blocked') to get the query parameter value as string.

2. Step 2: Verify condition and response

   public function handle($request, Closure $next) { if ($request->query('blocked') === 'true') { abort(403, 'Access denied'); } return $next($request); } checks if 'blocked' equals string 'true' and aborts with 403, then returns next middleware call.

3. Step 3: Compare other options

   public function handle($request, Closure $next) { if ($request->input('blocked') == true) { return redirect('home'); } return $next($request); } uses input() and redirects instead of aborting; public function handle($request, Closure $next) { if ($request->blocked === true) { abort(404); } return $next($request); } accesses property incorrectly; public function handle($request, Closure $next) { if ($request->has('blocked')) { return response('Blocked', 401); } return $next($request); } returns 401 but blocks any 'blocked' param regardless of value.

4. Final Answer:

   Checks $request->query('blocked') === 'true' and uses abort(403, 'Access denied') -> Option A

5. Quick Check:

   Use $request->query('blocked') and abort(403) [OK]

Hint: Use $request->query('param') and abort(403) to block [OK]

Common Mistakes:

• Using $request->blocked instead of query()
• Returning redirect instead of abort
• Not checking exact 'true' string value