HTTP and REST

What is HTTP (Hyper Text Transfer Protocol)?

It's how computers talk to each other in the internetz!

Call and Response.

Parts of HTTP Request and Response:

• URL - Location of data we are requesting
• Method/Verb - What type of action are we taking
• Headers - Extra info
• Body - Meat of the content
• Response Code - TLDR; did things break?

URL and Method only apply to Requests not Responses

HTTP Methods/Verbs

Along with the URL the method says WHAT we are trying to do

• GET - READ ONLY (no body can be sent) - Get information from a resource
• POST - Create something into the resource that wasn't there before or send a command
• PUT or PATCH - Changes an existing resource
• DELETE - Remove an existing resource
• OPTIONS - What can I do with this resource

HTTP Headers

Extra Info along with the data being sent or received

Common Headers

• Accept - What type of data do we know how to read (PLEASE SEND ME THIS or I will break... 😞)
• Content-Type - What is the format of information we are sending
• Authorization - Who are we and can we prove it

HTTP Body (what is this application/json thing anyway)

This is the main course!!!

JSON

Javascript Object Notation

Human and Machine readable way of describing data

{
  "foo": "bar",
  "names": [
    "Homer",
    "Marge"
  ],
  "child": {
    "x": 2,
    "y": false
  }
}

THINGS TO NOTE with JSON

• All quotes are double quotes
• All property names are in quotes
• Not variables
• Only a few data types
  • Booleans
  • Null/Undefined
  • Numbers (Integers or Decimals)
  • Strings
  • Arrays
  • Objects (POJOs)

To create a JSON string from a POJO in Javascript run JSON.stringify.

If you have a JSON string, to turn it into a POJO run JSON.parse.