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FAC4

The API

What is REST?

  • REST stands for REpresentational State Transfer. This refers to transferring "representations". You are using a "representation" of a resource to transfer resource state which lives on the server into application state on the client. See image below:

REST

  • It is a software architecture style consisting of guidelines and best practices for creating scalable web services
  • The use of REST is often preferred over the more heavyweight SOAP (Simple Object Access Protocol) style because REST does not leverage as much bandwidth, which makes it a better fit for use over the Internet

What is CRUD?

  • CRUD stands for Create, Read, Update and Delete
  • Sometimes known as SCRUD - the S being Search

  • For each letter in the CRUD acronym the HTTP Methods are as follows:

    • Create - POST (201 (Created), 'Location' header with link to /customers/{id} containing new ID.)
    • Read - GET (200 (OK), list of customers. Use pagination, sorting and filtering to navigate big lists.)
    • Update - PUT (404 (Not Found), unless you want to update/replace every resource in the entire collection.)
    • Delete - Delete (404 (Not Found), unless you want to delete the whole collection—not often desirable.)

    What is Routing?

  • "Routing" means, we want to handle requests to different URLs differently

  • Making different HTTP requests point at different parts of our code is called "routing"

The server.js and handler.js files - a basic skeleton for the RESTful CRUD API

server.js

var http = require("http");
var handler = require("./handler");
var port = 4000;


//*** List of Routes and Associated Handler Functions ***//
var routes = {}
routes["/"] = handler.home;
routes["/create"] = handler.create;
routes["/update"] = handler.update;



//*** Invokes the right handler or throws error ***//
var router = function(req, res){
    var url = req.url;
    console.log("request received for ", url);


    if (typeof routes[url] === 'function'){
        routes[url](req, res); 
    } else {
        console.log('Error, route for ', url, 'does not exist');
        res.writeHead(404, {"Content-Type": "text/plain"});
        res.end(" ERROR!!");
    }
}


http.createServer(router).listen(port);

console.log('Server running on port', port);

handler.js


module.exports = {


    home: function handler(req, res) {
        // console.log("Request for " + pathname + " received.");

        res.writeHead(200, {"Content-Type": "text/plain"});
        res.write("Welcome");
        res.end(" to Testing");

    },

    create: function handler(req, res) {
        // console.log("Request for " + pathname + " received.");

        res.writeHead(200, {"Content-Type": "text/plain"});
        res.write("Welcome");
        res.end(" to create article");

    },

    update: function handler(req, res) {
    // console.log("Request for " + pathname + " received.");

    res.writeHead(200, {"Content-Type": "text/plain"});
    res.write("Welcome");
    res.end(" to update article");

    },

    //createArticle

    //updateArticle

    //deleteArticle

    //viewArticle


}

};