RESTFUL API USING NODE.JS WITH EXPRESS 

ABOUT ME RAVINDRA KUMAR Web Enthusiast, Open Source Addict FRONT END ENGINEER @ CLEARTRIP hacker, bug fixer, benchmark runner Email: ravidsrk AT gmail.com Twitter: @ravidsrk Github: /ravidsrk ravidsrk almost everywhere else. 

AGENDA Quick overview of REST! Building REST API using Node with Express 

WARNING BEFORE WE START REST != MVC Do not think in controllers, id’s, actions, models, views, plugins,helpers etc... REST != CRUD *Caution: Not following advice will result in severe damage and makes me SAY: I TOLD YOU SO 

WHAT IS REST? 

WHAT IS REST?? Roy Fielding (Guy who first defined REST in his dissertation on Architectural Styles) said: REST is a coordinated set of architectural constraints that attempts to minimize latency and network communication while at the same time maximizing the independence and scalability of component implementations. This is achieved by placing constraints on connector semantics where other styles have focused on component semantics. 

MAIN PRINCIPLES OF REST Identification of resources Manipulation of resources Self-descriptive messages 

IDENTIFICATION OF RESOURCES !(CACHEABLE) !(SCALABLE) !(READABLE) YOU ARE DOING IT WRONG... :( /index.php?action=getarticle&id=5 /default/article/5/4/6/size 

IDENTIFICATION OF RESOURCES We want all articles We want the first comment of the fourth photo for the fifth article We want all comments of the fourth photo for the fifth article CACHEABLE! SCALABLE! READABLE! /articles /articles/5/photos/4/comments/1 /articles/5/photos/4/comments 

IDENTIFICATION OF RESOURCES ✗ /photos/order/size/limit/5 ✗ /photos/limit/5/order/size ✓ /photos?order=size&limit=5 ✓ /photos?limit=5&order=size FILTERING THROUGH A QUERY STRING, NOT THE URI 

MANIPULATION OF RESOURCES Create Retrieve Update Delete But please note that REST != CRUD 

MANIPULATION OF RESOURCES Create = POST Read = GET Update = PUT Delete = DELETE CRUD TO HTTP VERB MAPPING 

MANIPULATION OF RESOURCES Resource POST (create) GET (read) PUT (update) DELETE (delete) /users create a new user list users bulk update users delete all users /users/1234 error show 1234 if exists update 1234, else error delete 1234 

SELF-DESCRIPTIVE MESSAGES Stateless! All information for processing is available: How? (method + content-type) What? (URI) When? (preconditions) Who? (authentication) 

SELF-DESCRIPTIVE MESSAGES GET /speaker/1234 HTTP/1.1 Host: www.jsfoo.com Accept: application/vnd.jsfoo.nl+xml ; version: 1.0 Authorization: OAuth oauth_nonce=”123” ... If-None-Matched: absad12412414 HOW (METHOD) 

SELF-DESCRIPTIVE MESSAGES GET /speaker/1234 HTTP/1.1 Host: www.jsfoo.com Accept: application/vnd.jsfoo.nl+xml ; version: 1.0 Authorization: OAuth oauth_nonce=”123” ... If-None-Matched: absad12412414 HOW (CONTENT-TYPE) 

SELF-DESCRIPTIVE MESSAGES GET /speaker/1234 HTTP/1.1 Host: www.jsfoo.com Accept: application/vnd.jsfoo.nl+xml ; version: 1.0 Authorization: OAuth oauth_nonce=”123” ... If-None-Matched: absad12412414 WHAT 

SELF-DESCRIPTIVE MESSAGES GET /speaker/1234 HTTP/1.1 Host: www.jsfoo.com Accept: application/vnd.jsfoo.nl+xml ; version: 1.0 Authorization: OAuth oauth_nonce=”123” ... If-None-Matched: absad12412414 WHEN 

SELF-DESCRIPTIVE MESSAGES GET /speaker/1234 HTTP/1.1 Host: www.jsfoo.com Accept: application/vnd.jsfoo.nl+xml ; version: 1.0 Authorization: OAuth oauth_nonce=”123” ... If-None-Matched: absad12412414 WHO 

CODE DEMO 

SUMMARY Be RESTful Only 2 URLs No verbs Use nouns as plurals Sweep complexity behind the ‘?’ Borrow from leading APIs 

QUESTIONS! 

THANK YOU!