cwNotes

####Creating Restful APIs using Node.js and Express

1.imp while learning any thing 
    1.What is the topic
    2.Why is topic(what problem solve etc)
    3.How 

2. WebSite              |     WebApp 
  static content          interative     
   only read

#KISS(keep it Simple Silly)

3.WebApplication
  1.FrontEnd
  2.BackEnd
  3.DataBase

*why Nodejs use in BackEnd
  because by learning js you can use in both F and B 


Backend(APIs)
  APIs --> 2 system talk to each other with APIs

history of APIs
  1.SOAP(Simple object  protocol) uses XML
  2.SOAP is very slow (because of XML)
        whether is language or human if you can't change yourself yu will replace 
  3.SOAP is replace with REST

REST (Representational state Transfer)
    1.practical and flexible(may json,xml)
    2.I am Fast(because it uses JSON)

meaning of rest
data ka state ka jo represent wo Transfer ho ta rahe ta hai from one application to another i.e REST
  (eg DataBase give data in tabular format Backend pass the data in json format and FrontEnd show it in img format)

REST 
   everything revolve around (Resources)data(crud)
   [we perform crud on  data]

<JO bhi application computer mai run hota hai uska ek port number ho ta hai>
How will do (by URI)
    1.which computer(ip address)
    2.which application(port number)
    3.which file
                                {ipAddress:PortName/appName/Resouorce}
eg                              {111.24.56.69:7777:/jioradar/location/1234}

REST is build on http(already support CRUD)C -> POST R GET U PUT D DELETE

Http verb + URI = Restful API endpoint
[post 121.0.4.9:8080/bms/movies/dhoom]
[GET 121.0.4.9:8080/bms/movies/dhoom]
[put 121.0.4.9:8080/bms/movies/dhoom]
[delete 121.0.4.9:8080/bms/movies/dhoom]

we human need environment(oxygen,water,soil,etc)
~programmig language also need environment(runtime environment)
js runtime environment is known as NodeJs

synchronous processing  -> one time one job
asynchronous processing -> one time many job

Framework -> Minimum quality, Boiler plate, structure
     express is framwork of nodejs
              we can easily make server with help of express
              support middleware(noting but function consists
                                (object req,obj res,obj next))

Library -> set of reusable code

package.json ->consist of all imp info of project



Backend
  1.Routes      (check the req is valid or not)
  2.Controller (main Logic)
  3.Model      (access the database)
Build M->C->R