REST API’s¶

REpresentational State Transfer

resource: “ding” (concreet/abstract/fysiek/virtueel)
URL: Uniform Resource Locator: identificatie van resource
representation (document): beschrijft toestand van resource
methods: voor opvragen en veranderen van resource-toestand
- GET, POST, PUT, DELETE, PATCH, …

REST is verzameling afspraken/principes, passend bij het web.

HTTP methods¶

idempotent: geen verschil tussen 1x en vaker
belangrijk bij onbetrouwbare communicatie/uitvoering

method	toestand?	idempotent?
GET	onveranderd	ja
POST	veranderd	nee
PUT	veranderd	ja
DELETE	veranderd	ja

CRUD¶

methods voor collectie van things
en voor individuele things

method	`/things`	`/things/id`
GET	get all things (ids)	get state of thing `id`
POST	create new thing	-
PUT	-	set/update thing `id`
DELETE	-	delete thing `id`

Voorbeeld: Trello¶

https://trello.com

Begrippen:

boards
lists (per board)
cards (per list)
actions; users; organizations; …

Trello API: https://developer.atlassian.com/cloud/trello/

Importeren Python libraries¶

import requests
import json

Authenticatie/autorisatie¶

API-key: identificeert gebruiker

Genereren/ophalen via:

https://trello.com/app-key/

api_key = input("API-key? ")

API-token¶

API-token fungeert als username/password

Genereren via:

url = "https://trello.com/1/authorize?expiration=1day&name=MyTestToken&scope=read,write&response_type=token&key=" + api_key
print(url)

token = input("token? ")

Opvragen van borden¶

parameters zijn de parameters achter het ?

fields geeft aan welke velden in het resultaat nodig zijn.

parameters = {
   'key': api_key,
   'token': token,
   'fields': 'name,id'
}

response = requests.get(
   "https://api.trello.com/1/members/me/boards",
   headers={"Accept": "application/json"},
   params=parameters
)
response.status_code

boards = response.json()
boards

for board in boards:
    print(board["name"], " - ", board["id"])

boards[-1]

Opvragen van lists¶

board_id = boards[-1]["id"]

parameters = {
   'key': api_key,
   'token': token,
   'fields': 'name,id' 
}

response = requests.get(
   "https://api.trello.com/1/boards/{id}/lists".format(
       id = board_id
   ),
   headers={"Accept": "application/json"},
   params=parameters
)
response.status_code

lists = response.json()
lists

Opvragen van de cards van een list¶

list_id = lists[0]["id"]

parameters = {
   'key': api_key,
   'token': token,
   'fields': 'name,id' 
}

response = requests.get(
   "https://api.trello.com/1/lists/{id}/cards".format(
       id = list_id
   ),
   headers={"Accept": "application/json"},
   params=parameters
)
response.status_code

cards = response.json()
cards

Opvragen van een card¶

card_id = cards[0]["id"]

parameters = {
   'key': api_key,
   'token': token,
   'fields': "name,desc,id,url"
}

response = requests.get(
   "https://api.trello.com/1/cards/{id}".format(
       id = card_id
   ),
   headers={"Accept": "application/json"},
   params=parameters
)
response.status_code

my_card = response.json()
my_card

Een nieuw board¶

Maak een nieuw board aan, met de default-lijsten:

To Do, Doing, Done

parameters = {
   'key': api_key,
   'token': token,
   'name': "API test board"
}

response = requests.post(
   "https://api.trello.com/1/boards",
   headers={"Accept": "application/json"},
   params=parameters
)
response.status_code

my_board = response.json()
my_board

Bepaal lijsten¶

parameters = {
   'key': api_key,
   'token': token,
   'fields': 'name,id' 
}

response = requests.get(
   "https://api.trello.com/1/boards/{id}/lists".format(
       id = my_board["id"]
   ),
   headers={"Accept": "application/json"},
   params=parameters
)
response.status_code

my_lists = response.json()
my_lists

Lists in Python dictionary¶

list_ids = {}
for elem in my_lists:
    print(elem)
    name = elem["name"]
    list_ids[name] = elem["id"]

list_ids["To Do"]

Nieuwe card in To Do list¶

parameters = {
   'key': api_key,
   'token': token,
   'name': "A new card",
   'desc': "A card generated via the API",
   'pos': 'top',
   'idList': list_ids["To Do"]
}

response = requests.post(
   "https://api.trello.com/1/cards",
   headers={"Accept": "application/json"},
   params=parameters
)
response.status_code

new_card = response.json()
new_card

Move card to Doing list¶

parameters = {
   'key': api_key,
   'token': token,
   'idList': list_ids["Doing"]
}

response = requests.put(
   "https://api.trello.com/1/cards/{id}".format(
       id = new_card["id"]
   ),
   headers={"Accept": "application/json"},
   params=parameters
)
response.status_code

new_card = response.json()
print(new_card["url"])

Delete card¶

parameters = {
   'key': api_key,
   'token': token
}

response = requests.delete(
   "https://api.trello.com/1/cards/{id}".format(
       id = new_card["id"]
   ),
   headers={"Accept": "application/json"},
   params=parameters
)
response.status_code

Delete board¶

parameters = {
   'key': api_key,
   'token': token
}

response = requests.delete(
   "https://api.trello.com/1/boards/{id}".format(
       id = my_board["id"]
   ),
   headers={"Accept": "application/json"},
   params=parameters
)
response.status_code

Nu zelf aan de slag…

Het programmeerbare web