Code Explainers

Code explainers tagged #middleware

javascript 
const ROLE_PERMISSIONS = {
  admin: ['users:read', 'users:write', 'billing:read', 'billing:write'],
  manager: ['users:read', 'billing:read'],
  member: ['users:read'],

Role-based permissions middleware in Express

authorization middleware rbac
Intermediate 9 steps
javascript 
const express = require('express');
const app = express();
 
app.get('/health', (req, res) => res.json({ status: 'ok' }));

Graceful shutdown in an Express server

graceful-shutdown signal-handling connection-tracking
Advanced 9 steps
php 
<?php
 
namespace App\Http\Middleware;
 

Resolving the current team in Laravel middleware

middleware multi-tenancy cookies
Intermediate 8 steps
python 
import os
from pathlib import Path
 
BASE_DIR = Path(__file__).resolve().parent.parent.parent

How a Django settings module is wired

configuration environment-variables middleware
Intermediate 8 steps
javascript 
const express = require('express');
const { AsyncLocalStorage } = require('async_hooks');
const { randomUUID } = require('crypto');
 

Per-request logging context in Express

async-local-storage middleware structured-logging
Advanced 8 steps
go 
package middleware
 
import (
	"bytes"

Idempotent requests in Gin with Redis

idempotency caching middleware
Advanced 10 steps
ruby 
class Pipeline
  def initialize
    @middlewares = []
  end

Building a middleware pipeline in Ruby

closures middleware composition
Advanced 8 steps
go 
package middleware
 
import (
	"context"

A deadline-enforcing HTTP middleware in Go

middleware context goroutines
Advanced 7 steps
go 
package middleware
 
import (
	"net/http"

Localized validation errors in Gin

middleware internationalization validation
Intermediate 8 steps
php 
<?php
 
namespace App\Http\Controllers;
 

Email confirmation with signed URLs in Laravel

signed-urls email-verification middleware
Intermediate 6 steps
javascript 
import { NextResponse } from 'next/server';
 
const locales = ['en', 'fr', 'de', 'es'];
const defaultLocale = 'en';

Locale routing with Next.js middleware

middleware i18n content-negotiation
Intermediate 10 steps
go 
package middleware
 
import (
	"crypto/sha256"

Deduplicating concurrent requests in Gin

singleflight request-coalescing middleware
Advanced 8 steps
javascript 
const express = require('express');
const cookieParser = require('cookie-parser');
 
const router = express.Router();

Remember-me login with signed cookies in Express

authentication signed-cookies sessions
Intermediate 9 steps
rust 
use std::time::Duration;
 
use axum::{
    http::{header, HeaderValue, Request},

Serving fingerprinted assets in Axum

static-assets http-caching middleware
Intermediate 7 steps
python 
from starlette.middleware.base import BaseHTTPMiddleware
from starlette.requests import Request
from starlette.responses import JSONResponse, Response
from starlette.status import HTTP_413_REQUEST_ENTITY_TOO_LARGE

Enforcing a max request body size in FastAPI

middleware streaming request-limits
Advanced 6 steps
go 
package admin
 
import (
	"net/http"

Building a protected admin area in Gin

routing middleware authentication
Intermediate 6 steps
python 
import logging
import uuid
from contextvars import ContextVar
 

Request ID tracing in FastAPI middleware

middleware context-variables request-tracing
Intermediate 7 steps
go 
package middleware
 
import (
	"errors"

Capping request body size in Gin

middleware request limits error handling
Intermediate 5 steps