محاضرة قوة الرست من المهندس تامر عبد الراضي

2. ‫ُ ةِّ سِ ّتْ ّ‬
‫قور ة رست‬
‫‪Power of REST‬‬
‫إعداد: م/ تامر محمد عبد الراضي‬

3. ‫مقدمة عن‬
‫‪HTTP‬‬

4. HTTP
●
Hyper-Text Transfer Protocol
●
Client-Server networking protocol
●
Text based → Interoperability
●
URL Examples:
●
www.example.com/pages/first.htm
●
www.blog.com/posts/hello-world

5. HTTP Methods
●
HEAD
●
GET
●
POST
●
PUT
●
DELETE
●
TRACE
●
OPTIONS
●
CONNECT
●
PATCH

6. GET
●
used retrieve information
●
Doesn't have a side effect on the server
side = No writes
●
Cacheable

7. POST
●
Add new information
●
Append entry in a collection/table

8. PUT
●
Update existing information
●
Create new information with a known id

9. DELETE
●
Remove an entity

10. HTTP Status Codes
●
200 OK
●
201 Created
●
400 Bad Request
●
401 Unauthorized
●
404 Not Found
●
500 Internal Server Error

11. ‫يعني ايه رست ؟‬
Representational State Transfer
A client has a state ( set of variables' values)
The client initiates a request to a resource URI
The server response with a representation of the resource.
The representation places the client application in a new state.
Thus, the client application changes (transfers) state with each
resource representation → Representational State Transfer!

12. REST
● Software Architecture Style
● Introduced by Roy Fielding
● Based on HTTP

13. Characteristics of REST
●
Stateless
●
Each request from any client contains all of the information
necessary to understand the request
●
uniform interface
●
GET, POST, PUT, and DELETE
●
URIs
●
resources that are uniquely identified by URIs
●
→ http://example.com/orders/101230/customer

14. REST Request consists of ...
●
Resources
●
nouns
●
Identified by a URI
●
Methods
●
verbs
●
GET, POST, PUT, and DELETE
●
Sate Representation
●
Session, parameters

15. Example: Blog System
Let's Design our Blog's API!

16. Functions of Our Blog
●
Login
●
Logout
●
Write a Post
●
Delete a Post
●
Edit a Post
●
Read a Post
●
Comment on a Post
●
Delete Comment
●
Edit a comment
●
Like a post
●
Like a comment

17. Analyze, extract entities
● Login = Create a session ●
Entities (Nouns)
Logout = Delete the session
Session
●
●
● Write a Post ●
Post
● Delete a Post
– Likes
● Edit a Post – Comment
● Read a Post ●
Likes
● Comment on a Post
● Delete Comment
● Edit a comment
● Like a post = Add a like to post
● Like a comment = Add a like to
comment

18. Login
● URI: http://api.blog.com/session
● Method: POST
● Parameters: user-name, password
● Return
● 201 – Created
● 400 – Bad request

19. Logout
● URI: http://api.blog.com/session
● Method: DELETE
● Parameters: N/A
● Return
● 200 – OK

20. Write a Post
● URI: http://api.blog.com/posts
● Method: POST
● Parameters: title, body
● Return
● 201 – Created
● 400 – Bad request

21. Write/Edit a Post
● URI: http://api.blog.com/posts/hello-world
● Method: PUT
● Parameters: title, body
● Return
● 201 – Created
● 400 – Bad request

22. Delete a Post
● URI: http://api.blog.com/posts/hello-world
● Method: DELETE
● Parameters: N/A
● Return
● 200 – OK
● 401 – Not authorized

23. Read a Post
● URI: http://api.blog.com/posts/hello-world
● Method: GET
● Parameters: N/A
● Return
● 200 – OK
● 404 – Not found

24. Comment on post
● URI: http://api.blog.com/posts/hello-
world/comments
● Method: POST
● Parameters: comment
● Return
● 201 – Created
● 400 – Bad request

25. Edit a Comment
● URI: http://api.blog.com/posts/hello-
world/comments/123
● Method: PUT
● Parameters: comment
● Return
● 201 – Created
● 400 – Bad request

26. Delete a comment
● URI: http://api.blog.com/posts/hello-
world/comments/123
● Method: DELETE
● Parameters: N/A
● Return
● 200 – OK
● 401 – Not authorized

27. Like a post
● URI: http://api.blog.com/posts/hello-
world/likes
● Method: POST
● Parameters: N/A
● Return
● 201 – Created

28. Like a comment
● URI: http://api.blog.com/posts/hello-
world/comments/123/likes
● Method: POST
● Parameters: N/A
● Return
● 201 – Created

29. Data representation
● REST supports variety of formats
● XML
● JSON
● X(HTML)
REST supports content negotiation
●
● Header-based:
GET /foo
Accept: application/json
● URL-Based
http://api.blog.com/posts/hello-world.json

30. JSON
●
JavaScript Object Notation
●
representing simple data structures and
associative arrays, called objects.

31. {
'Post' : {
'title' : 'hello-world',
'body': 'bla bla bla …',
'comments' : {
'Comment' : [
{'name':'Folaan', 'comment':'Hi'},
{'name':'3ellan', 'comment':'Hello'}
]
},
'likes': ['Follan', '3ellan']
}
}

32. ?
Questions