Notes

Http Semantics

HTTP is a stateless protocol used to transfer informations in a server-client model. It defines a set of methods for CRUD operations and additional methods and is the main protocol that powers the web.

Methods

  • GET: Retrieve the current rappresentation of a resource
  • HEAD: Same as get but without body
  • POST: Perform resource-specific processing on the request payload.
  • OPTIONS: used to request communications options for the target source
  • PUT: Replace all reppresentation of the resource with the content of body
  • DELETE: Remove all reppresentation of the resource on the server
  • TRACE: Request a loop-back of the request message.
  • PATCH: (defined in RFC 5789 not in RFC 7231) Partial modification of a remote resource.

All general-purpose servers MUST support the methods GET and HEAD.

All other methods are OPTIONAL.

Safe Methods

Methods that are read-only: GET, HEAD, OPTIONS and TRACE. reasonable use of a safe method is not expected to cause any harm, loss of property, or unusual burden on the origin server.

Idempotent Methods

Multiple request using an idempotent method should have the same effect for a single request.

Idempotent methods: Safe methods, DELETE and PUT.

Cacheable methods

Request methods that can be stored for future use.

GET, HEAD and POST.

Note: Most implementation do not support caching of POST.

Request Header Fields

HOST

Provides the host and port from the server's uri. A Client MUST send a Host header field in all HTTP/1.1 request messages.

GET /api/resource/2 HTTP/1.1
Host: api-domain.com

ACCEPT

Header field used to notify of the acceptable media types for the client

ACCEPT-CHARSET

The acceptable charset of the textual response body for the client, generally set by user agents.

ACCEPT-ENCODING

The acceptable encoding to use in the response, generally set by user agents. A request without an Accept-Encoding header field implies that the user agent has no preferences regarding content-codings.

ACCEPT-LANGUAGE

specifies the preferred language for the response.

REFERRER

Set by user agents to specify the URI resource from which the request was made(used generally in ajax).

USER-AGENT

Program that on behalf of the user request the data.

Reference