Learning REST APIs

Question 1

What does REST stand for

Answer 1

Representational State Transfer

Question 2

What does API stand for

Answer 2

Application Programing Interface

Question 3

What is REST?

Answer 3

Representational State Transfer refers to a group of software architecture design constraints that bring about efficient, reliable, and scalable systems

Question 4

A representational state is transferred as a ____ which means the website doesn’t have to reload the whole page

Answer 4

Data Object (As opposed to having to load the new pages whole set of HTML Code)

Question 5

What is an API

Answer 5

A set of features and rules that exist inside a software program enabling interaction between the software and other items, such as other software or hardware

Question 6

what is the collection of tools used to access and work with REST resources?

Answer 6

API (Application Programming Interface)

Question 7

What does URI stand for?

Answer 7

Universal Resource Identifier

Question 8

What is a URI?

Answer 8

“A compact sequence of characters that identifies an abstract or physical resource” that “provides a simple and extensible means for identifying a resource”

Question 9

What is the most generic way to name and locate a web resource?

Answer 9

URI?

Question 10

What does URL Stand for?

Answer 10

Subset of the URI that identifies a resource and explains how to access that resource (https:// or ftp://)

Question 11

What does URN stand for?

Answer 11

Universal Resource Name

Question 12

What is a URN? How is that different from a URL?

Answer 12

Its the unique name of a URI. The URL includes the location which is not part of the URN.

Question 13

What are the Six Constraints of REST

Answer 13

1. Client - server architecture
2. Statelessness
3. Cacheability
4. Layered system
5. Code on demand
6. Uniform interface

Question 14

REST Constraint: Client - server architecture

Answer 14

This constraint ensures proper separation of concerns. The client manages user interface concerns while the server manages data storage concerns

Question 15

REST Constraint: Statelessness

Answer 15

No client context or information, aka “state”, can be stored on the server between requests.

Question 16

REST Constraint: Cacheability

Answer 16

All REST responses must be clearly marked as cacheable or not cacheable

Question 17

REST Constraint: Layered system

Answer 17

The client cannot know, and shouldn’t care, whether it’s connected directly to the server or to an intermediary like a CDN or mirror

Question 18

REST Constraint: Code on demand

Answer 18

Servers are allowed to transfer executable code like JavaScript and compiled components to clients

Question 19

REST Constraint: Uniform interface

Answer 19

6.1 Resource identification in request
The URI request must specify what resource it is looking for and what format the response should use

6.2 Resource manipulation through representations
Once a client has a representation of a resource, it can modify or delete the resource

6.3 Self-descriptive messages
Self descriptive messages (messages must identify their format so they can be parsed

6.4 Hypermedia as the engine of application state
Once a client has access to a REST service, it should be able to discover all available resources and methods through the hyperlinks provided

Question 20

who are the clients that consume the REST API?

Answer 20

This is the website or app that sends the request and parses the response

Question 21

What is reqres.in?

Answer 21

This is a website that allows REST messages to be sent and will return data in order to allow users to test

Question 22

What is a “resource” in REST

Answer 22

Any information that can be named can be a resource such as a document or image, a temporal service, a collection of other resources, a non-virtual object and so on

Question 23

what does a REST server generate for clients upon request?

Answer 23

A representation of the requested resource. This allows multiple clients to access the same data at the same time

Question 24

what are HTTP methods?

Answer 24

These are the commands (verbs) used to interact with the server. Such as using GET to retrieve information from the resource

Question 25

What are the three methods to send data to the resource from the client?

Answer 25

POST - Create a new resource and add it to a collection on the target site

PUT - used to update all data for a “singleton” resource based on ID by replacing all existing content

PATCH - Used to modify an existing singleton resource without replacing everything

Question 26

What are the return codes for a POST method?

Answer 26

201 - created
401 - unauthorized
409 - conflict (resource already exists)
404 - not found (if it’s sent to a resource that doesn’t exist)

Question 27

what are the return codes for a PUT method

Answer 27

200 OK
401 - Unauthorized
404 - Not Found
405 - Method not allowed (when sent to a collection resource, since PUT can only update a singleton resource)

Question 28

What are the return codes for a PATCH method

Answer 28

200 OK
401 - Unauthorized
404 - Not Found
405 - Method not allowed (when sent to a collection resource, since PATCH can only update a singleton resource)

Question 29

What are the return codes for a DELETE method

Answer 29

200 - OK
401 - Unauthorized
404 - Not Found

405 - Method not allowed (Can only be used with Singleton resources!)

Question 30

What are the OPTIONS and HEAD methods for?

Answer 30

Options returns a description of the communication options for the target resource

Head returns only the header of that response

Question 31

What will every response to a REST query contain?

Answer 31

a HEAD with information about what happened including the HTTP Status message

Question 32

What are the http response status codes in the following ranges:
100s
200s
300s
400s
500s

Answer 32

100s - Information
200s - Success
300s - Redirection
400s - Client error
500s - Server error

Question 33

What are 100s codes

Answer 33

These are informational and are rare. Generally used to say please wait for server or something of that nature

Question 34

what are 200s codes

Answer 34

These are for versions of success
200 - OK

201 - Created (new resource created)

204 - No content (server processed request but returned nothing)

Question 35

What are the 300s codes

Answer 35

These are forms of redirection
301 - Moved permanently (gives the new URI for future requests)

302/303 - Found at this other URL

307 - Temporary redirect

308 - Resume incomplete

Question 36

What are the 400s codes

Answer 36

These are forms of Client errors
400 - Bad request (request is malformed or too large)

401 - Unauthorized (client lacks authentication)

403 - Forbidden (outright refused, maybe client isn’t logged in)

404 - Not found (resource does not exist at all)

405 - Method not allowed (used when a method is used that isn’t compatible with the resource being accessed)

Question 37

What are the 500s codes

Answer 37

These are forms of Server errors
500 - Internal server error

502 - Bad gateway (received invalid response)

503 - Service unavailable (server is overloaded or temporarily unavailable)

Question 38

when sending a REST request which methods are available for the target resource can be changed by adding what to the request?

Answer 38

Adding authentication such as line 2 in the following example:

1. HEAD http://restful.dev/wp-json/wp/v2/posts
2. Authorization: Basic andmbowe password

Question 39

What is needed (after the URI and authorization) to POST something to a resource?

Answer 39

a content type to describe the type of data that will be sent (line 3) and the data itself (line 4+)

1. HEAD http://restful.dev/wp-json/wp/v2/posts
2. Authorization: Basic andmbowe password
3. Content-Type: application/json
4. {
5. “title”: “A post created via the REST API!”,
6. “content”: “abc123”
7. “Status”: “publish”, (it would be in draft without this)
8. “author”: 1
9. }