Code Explainers

Code explainers tagged #middleware

go 
package middleware
 
import (
	"net/http"

Wrapping Gin requests in a DB transaction

middleware transactions error-handling
Intermediate 8 steps
php 
<?php
 
namespace App\Http\Middleware;
 

Caching HTTP responses with Laravel middleware

middleware caching http
Intermediate 8 steps
javascript 
const { Pool } = require('pg');
 
const pool = new Pool({
  connectionString: process.env.DATABASE_URL,

Per-request Postgres connections in Express

connection-pooling middleware transactions
Intermediate 8 steps
python 
import time
import threading
from flask import Flask, request, jsonify, g
 

A token-bucket rate limiter in Flask

rate-limiting token-bucket middleware
Intermediate 7 steps
go 
package middleware
 
import (
	"context"

Per-tenant daily rate limiting in Gin

rate-limiting middleware redis
Intermediate 8 steps
rust 
use axum::{
    body::{Body, Bytes},
    extract::Request,
    http::StatusCode,

Logging request and response sizes in Axum

middleware http streaming-bodies
Advanced 8 steps
go 
package handler
 
type flightResult struct {
	status int

Deduping in-flight requests in Gin

middleware concurrency deduplication
Advanced 9 steps
javascript 
const express = require('express');
const { createProxyMiddleware, fixRequestBody } = require('http-proxy-middleware');
 
const router = express.Router();

Building an API gateway proxy in Express

reverse-proxy middleware api-gateway
Intermediate 6 steps
go 
package middleware
 
import (
	"net/http"

Per-IP write rate limiting in Gin

rate-limiting middleware concurrency
Intermediate 8 steps
go 
package middleware
 
import (
	"net/http"

A content-type guard middleware in Gin

middleware closures http
Intermediate 7 steps
typescript 
import {
  Controller,
  All,
  Req,

Catch-all routes and error shaping in NestJS

exception-handling routing middleware
Intermediate 6 steps
go 
package middleware
 
import (
	"net/http"

Role-based access control middleware in Gin

middleware authorization closures
Intermediate 7 steps
python 
from fastapi import FastAPI, Request, status
from fastapi.encoders import jsonable_encoder
from fastapi.exceptions import RequestValidationError
from fastapi.responses import JSONResponse

Redacting sensitive fields in FastAPI errors

validation error-handling security
Intermediate 7 steps
go 
func UserDashboardCache(rdb *redis.Client, ttl time.Duration) gin.HandlerFunc {
	return func(c *gin.Context) {
		claims, ok := c.Get("claims")
		if !ok {

Per-user response caching in Gin with Redis

middleware caching redis
Advanced 9 steps
rust 
use std::{collections::HashSet, sync::Arc};
 
use axum::{
    body::Body,

Feature-flag middleware in Axum

middleware async shared-state
Advanced 7 steps
go 
package middleware
 
import (
	"compress/gzip"

How gzip HTTP middleware works in Go

middleware compression object-pooling
Intermediate 7 steps
typescript 
import {
  CallHandler,
  ExecutionContext,
  Injectable,

Recording HTTP metrics with a NestJS interceptor

interceptor observability prometheus
Intermediate 5 steps
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