{"library":"middle-router","title":"Universal Middleware Router","description":"middle-router is a universal routing library designed for both client-side and server-side JavaScript applications, allowing URL changes to be processed through a series of asynchronous middleware functions. As of version 2.2.0, it provides a consistent API for managing routing logic across different environments. It distinguishes itself by integrating Koa-style `await next()` patterns for middleware execution, enabling control to flow downstream and then back upstream. This allows for complex lifecycle management around route changes, such as measuring execution time, handling exit conditions, or even prompting before navigation. The library leverages `path-to-regexp` for flexible path matching, similar to Express 4.x, and utilizes `middle-run` for robust middleware orchestration. While the provided examples often showcase integration with frameworks like Express and React, `middle-router` itself is entirely framework-agnostic, offering core routing functionality without imposing external dependencies. It focuses on providing a flexible and powerful middleware-based approach to handling application state changes tied to URLs. Its release cadence is stable, with new features and bug fixes rolled out incrementally.","language":"javascript","status":"active","last_verified":"Thu Apr 23","install":{"commands":["npm install middle-router"],"cli":null},"imports":["import Router from 'middle-router'","const Router = require('middle-router')","import Router from 'middle-router'; const myRouter = Router();"],"auth":{"required":false,"env_vars":[]},"quickstart":{"code":"import Router from 'middle-router';\n\nconst appRouter = Router()\n  .use(async ({ context, next }) => {\n    const start = Date.now();\n    console.log(`[Middleware 1] Entering: ${context.url}`);\n    await next(); // Pass control to the next middleware\n    const duration = Date.now() - start;\n    context.totalTime = duration;\n    console.log(`[Middleware 1] Exiting: ${context.url} (took ${duration}ms)`);\n  })\n  .use('/users/:id', async ({ params, resolve, context }) => {\n    console.log(`[Middleware 2] Matched /users/${params.id}`);\n    // Simulate async data fetching\n    await new Promise(res => setTimeout(res, 50));\n    const userData = { id: params.id, name: `User ${params.id}`, fetchedAt: Date.now() };\n    resolve(`<h1>User Profile</h1><p>ID: ${userData.id}</p><p>Name: ${userData.name}</p><p>Fetched at: ${userData.fetchedAt}</p>`);\n    console.log(`[Middleware 2] Resolved for /users/${params.id}`);\n  })\n  .use(async ({ resolve, context }) => {\n    console.log(`[Middleware 3] Default catch-all for: ${context.url}`);\n    resolve(`<h1>Welcome</h1><p>No specific route matched for ${context.url}.</p>`);\n  });\n\nasync function runExample() {\n  console.log('--- Routing /users/123 ---');\n  const userView = await appRouter.route('/users/123', { initialData: '...' });\n  console.log('Resolved View:', userView);\n  console.log('\\n--- Routing /about ---');\n  const aboutView = await appRouter.route('/about');\n  console.log('Resolved View:', aboutView);\n  console.log('\\n--- Routing / ---');\n  const homeView = await appRouter.route('/');\n  console.log('Resolved View:', homeView);\n}\n\nrunExample();","lang":"javascript","description":"This quickstart demonstrates how to create a `middle-router` instance, define asynchronous middleware functions for different paths, and use `router.route()` to process URLs, simulating both specific and default route handling in a Node.js environment.","tag":null,"tag_description":null,"last_tested":null,"results":[]},"compatibility":null}