codesnips
java 
package com.example.notifications;

import org.springframework.stereotype.Component;
import org.springframework.web.servlet.mvc.method.annotation.SseEmitter;

import java.io.IOException;

Live Browser Notifications with Spring Boot SseEmitter and a Broadcaster Service

spring-boot sse server-sent-events
by codesnips 3 tabs
javascript 
import { createContext, useCallback, useContext, useEffect, useMemo, useState } from 'react';

export const RouterContext = createContext(null);

export function RouterProvider({ children }) {
  const [path, setPath] = useState(() => window.location.pathname);

Client-Side Router with useRoute Hook and History API in React

react router hooks
by codesnips 3 tabs
rust 
#[derive(Debug, Clone, Copy)]
pub struct ByteRange {
    pub start: u64,
    pub end: u64, // inclusive
}

Serving HTTP Range Requests in Axum with Partial Content Responses

axum http range-requests
by codesnips 3 tabs
python 
import contextvars
import uuid

_correlation_id: contextvars.ContextVar[str] = contextvars.ContextVar(
    "correlation_id", default="-"
)

Propagating a Correlation ID Through contextvars in FastAPI

fastapi contextvars middleware
by codesnips 4 tabs
java 
@Entity
@Table(name = "invoices")
@FilterDef(
    name = "tenantFilter",
    parameters = @ParamDef(name = "tenantId", type = String.class)
)

Per-Tenant Row Filtering with Hibernate @Filter Enabled Per Request

hibernate jpa multi-tenancy
by codesnips 4 tabs
javascript 
const express = require('express');
const controller = require('../controllers/userController');

const router = express.Router();

router.use((req, res, next) => {

Versioning an Express API with Router-per-Version Mounts and a Shared Controller Module

express api-versioning rest
by codesnips 4 tabs
typescript 
export interface CartItem {
  id: string;
  name: string;
  price: number;
  quantity: number;
}

Type-Safe Shopping Cart with useReducer, Context, and a useCart Hook

react context usereducer
by codesnips 4 tabs
ruby 
module EventBus
  @subscribers = Hash.new { |h, k| h[k] = [] }

  class << self
    def subscribe(event_class, handler = nil, &block)
      callable = handler || block

In-Process Domain Event Bus with Subscribers in Rails

rails domain-events event-bus
by codesnips 4 tabs
python 
from decimal import Decimal

from django.db import models
from django.db.models import F, ExpressionWrapper, DecimalField

Annotate Invoice Line Totals in a Django ListView Queryset

django orm queryset
by codesnips 3 tabs
go 
package validate

import (
	"regexp"
	"unicode/utf8"
)

Per-Field Signup Validation Errors With a Reusable Validator in Go

go validation http
by codesnips 2 tabs
rust 
#[derive(Debug, Clone, PartialEq, Eq)]
pub struct Currency {
    pub code: &'static str,
    pub symbol: &'static str,
    pub exponent: u32,
}

Locale-Aware Money Formatting With Minor Units in Rust

rust money currency
by codesnips 3 tabs
java 
@RestController
@RequestMapping("/api/orders")
public class OrderController {

    private final OrderService orderService;

Testing a Spring Boot Controller Slice with @WebMvcTest, MockMvc and a Mocked Service

spring-boot testing mockmvc
by codesnips 3 tabs