HTTP

Objectives

Describe the pieces that make up a URL
Identify HTTP verbs
Describe makes up an HTTP request/response
Identify common HTTP status codes
Define the same-origin policy

What happens when you type google.com on your browser and hit enter?

Web Sequence Diagrams!

URI

Uniform Resource Identifiers

URLs are URIs

http://www.example.com:80/a/good/path.html?foo=bar#home

protocol/schema - a Standard. tells the computer how to read the information.

host/domain - Location. where the server is

port - window of server

path - path of a file or simply for more information

query string - passing information. searching or filtering

anchor - where in the page

Parts of the URL

HTTP Request

GET /resources/public-data/ HTTP/1.1
Host: bar.other
User-Agent: Mozilla/5.0 (Macintosh; U; Intel Mac OS X 10.5; en-US; rv:1.9.1b3pre) Gecko/20081130 Minefield/3.1b3pre
Accept: text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8
Accept-Language: en-us,en;q=0.5
Accept-Encoding: gzip,deflate
Accept-Charset: ISO-8859-1,utf-8;q=0.7,*;q=0.7
Connection: keep-alive
Referer: http://foo.example/examples/access-control/simpleXSInvocation.html
Origin: http://foo.example

HTTP Verbs

GET

POST

PUT

PATCH

DELETE

OPTIONS

RESTful Design

Representational state transfer (REST) or RESTful Web Services are one way of providing interoperability between computer systems on the Internet.

Best practices for the web to create a "uniform interface" for computers to talk to each other.

HTTP Response

HTTP/1.1 200 OK
Date: Mon, 01 Dec 2008 00:23:53 GMT
Server: Apache/2.0.61
Access-Control-Allow-Origin: *
Keep-Alive: timeout=2, max=100
Connection: Keep-Alive
Transfer-Encoding: chunked
Content-Type: application/xml

[XML Data]

HTTP Status Codes

Status OK

Moved Permanently

Not Modified

Unauthorized

Not Found

Service Unavailable

200

301

304

401

404

503

SO MUCH MORE

- TCP/IP

- JSON, XML

- Cookies, JWTs

- CORS

CORS

You will see this:

Don't worry about it for now. Look into same origin policy

Review

Describe the pieces that make up a URL
Identify HTTP verbs
Describe makes up an HTTP request/response
Identify common HTTP status codes
Define the same-origin policy

deck

By Roberto Ortega