REST and Hypermedia
External
- https://www.programmableweb.com
- https://learning.oreilly.com/videos/learning-path-resource-oriented/9781491960981
Internal
- Swagger
- API Concepts
- Amazon API Gateway Concepts
- Spring REST Concepts
- Best Practices for Naming REST API URIs
Overview
HTTP APIs often use the Representational State Transfer (REST) architectural style, which is developed around the following principles:
- Organize the API around resources.
- Communicate actions using HTTP methods.
- Model response around standard HTTP status codes.
API
Uniform Resource Locator (URL)
Uniform Resource Identifier (URI)
URN
Endpoint
A REST API endpoint is the interaction point where a specific URL is configured to receive web requests.
Resource
A resource is a logical entity that an application can access through a resource path. A resource is a top-level constituent of a REST API. Resources are sometimes referred to as the nouns of the API. A resource has a number of methods.
TODO: receive data from client via path, Spring REST Concepts: Spring_REST_Concepts#Via_Path
Resource Path
Path Parameter, Path Variable, Variable Path Part
Also referred to as "path variable" or "variable path part".
/something/{id}/something-else
Query
Query Parameter
Method
A method corresponds to a REST API request that is submitted by the user of the API to a resource and to the response returned to the user. Methods belong to resources, and are defined by combinations of resource paths and operations. The API methods represent the programming interface between the client and the API.
Request
A Method Request is part of the API's interface with the API's client.
Request Header
Request Body
Response
A Method Response is part of the API's interface with the API's client.
Response Header
Response Body
Per-Method Authorization
HTTP Protocol Semantics within a REST Application Context
Operations
A resource's operations are defined by HTTP verbs:
GET
Get a representation of a resource.
Also see:
POST
Create a new resource underneath the current one, based on the given representation. POST is non-idempotent. POST is an unsafe operation.
The appropriate response status code in case of successful creation is 201.
The Location header should contain the URL of the new resource.
Also see:
PUT
Replace the state of the given resource with the one described in the given representation. PUT is semantic opposite of GET: whereas GET requests are used to send a resource representation from server to client, PUT is used to send a resource representation from client to server. Semantically, PUT mens "put this data at this URL", replacing any data that is already there. PUT is intended to perform a wholesale replacement of the resource, rather than a partial update operation. The partial update can be performed with PATCH. Put is an idempotent operation. If any of the resource representation part is missing, that state will be overwritten with null.
Also see:
PATCH
Defined in RFC 5789.
Updates a resource by modifying part of the state of the given resource based on the given representation. If some bit of resource state is not mentioned in the representation, it should be left unmodified. PATCH is like PUT, but allows for fine-grained changes in resource state.
Also see:
DELETE
Destroy the resource.
The appropriate response status code in case of successful deletion is 204.
Also see:
HEAD
Get the headers that would be sent along with a representation of this resource, but not the representation itself. This method is mostly used when a client explores the API.
Also see:
OPTIONS
Discover which methods this resource responds to. This method is mostly used when a client explores the API.
Also see:
LINK
UNLINK
Representation
Representational State Transfer (REST)
RWA page 32
Multipurpose Internet Mail Extension (MIME)
MIME is an internet standard that extends the format of e-mail to support text in character sets other then ASCII, non-text attachments, such as audio, video, images, application programs, etc., message bodies with multiple parts and header information in non-ASCII characters sets. MIME is specified in six linked RFCs: RFC 2045, RFC 2046, RFC 2047, RFC 4288, RFC 4289 and RFC 2049.
MIME is relevant to HTTP. The content types define by MIME are used in the definition of HTTP content. HTTP clients use MIME content type headers to indicate the desired application to process the specific type of content they send. HTTP servers insert MIME content type information in all their responses.
MIME defines the following headers:
- MIME-Version
- Content-Type
- Content-Disposition
- Content-Transfer-Encoding
Media Type
A media type, also called media-type, content type or MIME type is a two-part string identifying the format of a document. Usually, knowing a document's format allows us to parse it. IANA (Internet Assigned Numbers Authority) is the official authority for the standardization and publication of media types. Within the context of REST, the media type is a format of a request and response body. Media types are specified by RFC6838 - Media Type Specifications and Registration Procedures.
The media type string consists of a type and a subtype. The subtype can be further be structured into a tree. A media type can optionally define a suffix and parameters:
type "/" [tree "." ] subtype ["+" suffix] *[";" parameter]
The currently registered types are: "application", "audio", "example", "font", "image", "message", "model", "multipart", "text" and "video".
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