Code Explainers

Code explainers tagged #validation

php 
<?php
 
namespace App\Services\Checkout;
 

Validating coupons with Laravel's Pipeline

pipeline chain of responsibility transactions
Intermediate 7 steps
php 
<?php
 
namespace App\Services;
 

How a password strength validator works in PHP

validation regular-expressions data-driven
Intermediate 8 steps
rust 
use chrono::{Duration, NaiveDate};
 
#[derive(Debug)]
pub struct DateRange {

Parsing and iterating date ranges in Rust

error-handling iterators parsing
Intermediate 7 steps
rust 
use axum::{
    async_trait,
    extract::{rejection::JsonRejection, FromRequest, Request},
    http::StatusCode,

A validated JSON extractor in Axum

extractors validation error-handling
Intermediate 8 steps
java 
public final class EncodingDetector {
 
    public enum Encoding {
        UTF_8, UTF_16LE, UTF_16BE, UTF_32LE, UTF_32BE, ASCII, UNKNOWN

Detecting text encoding from raw bytes in Java

byte-manipulation encoding-detection bitwise-operations
Intermediate 8 steps
python 
from enum import Enum
from typing import Annotated
 
from fastapi import FastAPI, Query, Request, status

Custom validation error responses in FastAPI

validation error-handling enums
Intermediate 8 steps
go 
package handlers
 
import (
	"net/http"

Custom struct-level validation in Gin

validation struct-tags cross-field
Intermediate 7 steps
typescript 
interface ContentRange {
  unit: string;
  start: number;
  end: number;

Parsing HTTP Content-Range headers in TypeScript

regex parsing validation
Intermediate 8 steps
python 
from django import forms
from django.contrib.auth import get_user_model
from django.shortcuts import redirect
from formtools.wizard.views import SessionWizardView

Building a multi-step form with Django wizards

form-wizard multi-step-forms session-state
Intermediate 8 steps
php 
<?php
 
namespace App\Services;
 

Validating coupons before applying a discount in Laravel

validation guard clauses business rules
Intermediate 7 steps
javascript 
const { z, ZodError } = require('zod');
 
function validate(schemas) {
  return (req, res, next) => {

A reusable Zod validation middleware for Express

middleware validation schema
Intermediate 8 steps
javascript 
const UNIT_MULTIPLIERS = {
  ms: 1,
  s: 1000,
};

Parsing CSS durations into milliseconds

parsing regular-expressions validation
Intermediate 6 steps
java 
@Controller
@RequestMapping("/employees")
public class EmployeeController {
 

Building a Spring MVC form controller

mvc form-handling validation
Intermediate 8 steps
php 
<?php
 
namespace App\Http\Controllers;
 

Processing refunds safely in Laravel

dependency injection validation database transactions
Intermediate 8 steps
ruby 
module WifiQrCode
  ESCAPE_CHARS = /([\\;,:"])/.freeze
 
  AUTH_TYPES = {

Building a Wi-Fi QR code payload in Ruby

string-formatting validation escaping
Intermediate 9 steps
go 
package handlers
 
import (
	"context"

A custom Gin validator backed by Redis

validation redis struct-tags
Intermediate 8 steps
python 
from io import BytesIO
from flask import Blueprint, abort, send_file
from reportlab.lib.pagesizes import LETTER
from reportlab.lib.units import inch

Streaming a generated PDF from a Flask route

pdf generation in-memory buffer file download
Intermediate 8 steps
javascript 
'use server'
 
import { z } from 'zod'
import { revalidatePath } from 'next/cache'

Handling form submits with Next.js Server Actions

server-actions validation form-handling
Intermediate 7 steps