Abstract
You are dealing with an exercise project. The aim is to create a demon that uses the Twitter API to fetch a list of images. It is intended to create an album based on a hashtag search. The app should create an album, runs every 20min and fetches the last photos posted on twitter. When the album reaches 100|200|300|400|501 photos it would be able to send an email.
The app exposes an API and a visual representation of the album. You can:
- Access a url in your browser that shows all the pictures
- Access a REST api that shows you the data structure of the pictures in your album
- Create a page and a link of the most 7 popular photos in the album and export it to Facebook
- Get email notifications when the album reaches particulars numbers of photos
- See the date/time when the photos were included
Install - Step 0 (optional but recommended)
Install mkvirtualenv globally:
sudo pip install virtualenv
sudo pip install virtualenvwrapper
Add mkvirtualenv script to your .bashrc file (local folder may vary).
echo 'source ~/.local/bin/virtualenvwrapper.sh' >> ~/.bashrc
source ~/.bashrc
Create a new env:
mkvirtualenv --python=python[2.7.12] twitter_album
(2.7.x, x may vary, tested with Python 2.7.*)
or
mkvirtualenv twitter_album
activate your virtual space:
workon twitter_album
Install - Step 1
Set your Twitter consumer_key
, consumer_secret
, access_token_key
, access_token_secret
in datasource/tasker/ConfMixin.py file.
Set your cool hashtag (topic
) in the same file.
Install - Step 2
pip install -r requirements.txt
python manage.py makemigrations app
python manage.py migrate
python manage.py runserver
Misc
Run tests:
./manage.py test
Admin UI:
python manage.py createsuperuser
Pick an username and a password. Point the browser to /admin
.
Exit virtualenv:
deactivate
Caveats
django-cron may do not work properly with virtualenv. To run it manually append these lines to /twitter_album/urls.py:
from datasource.tasker.TwitterTask import TwitterTask
TwitterTask()
Then run the server multiple times to populate your album. It is possible because the tasker class is decoupled from django-cron module.
Some exceptions are not handled (e.g. Authtentication error, Nertwork error, Range Xrate Limits error) because this is a demo exercise, not meant to go in production.
Facebook social button: may not work in cause the Button-App is not registered @Facebook. You can found it in every page. As required, it is visible also in the filtering 7-most-rated page.
Api usage
- Get all photos
/api
- Get photos by topic/hashtag (#carnival example)
/api/topic/%23carnival
- Get the most 7 popular photos
/api/topic/%23carnival/7
- Get photos by owner
/api/owner/{<owner_display_name>}
High level Design
The app is organised in 4 mainly "Packages".
-
Twitter_album That contains the settings and the urls whose Django looks when the app starts.
-
Datasoruce/Tasker It is a place that should contains the business logic related to the demon and it's work. The TwitterCron class calls the TwitterTask and uses the DataAccess class to save model data. DataAccess should be the only class - of this package - meant to communicate to the model.
-
App Contains the view logic (uses models and calls template of course). Provides an API.
-
Templates Django HTML templates
Tasker entity
TwitterTask class contains three methods:
-
connect() It does establish a connection to Twitter
-
search() It prepares the query (kv object) and calls GetSearch Twitter API. The first time it searches the most recent image on Twitter. Once got it, next times it prepares a query based on that one Twitter-ID. It uses max_id parameter to get older photos. It uses get_min_id_or_none() accessory method to calculate the minimun Twitter-ID of local photos. The minimun ID will be considered as max_id for the current API invocation. So, the demon will always search for older photos. To search freshes photos change Min to Max in DataAccess class, or write an entropy that choose every time if it will search for older of newer photos .
-
process_list() Processes the list of results. It checks if exists the image url, the owner, and the favourite counter. Then it calls save_photo to save the entity (the model will checks if the image urls exits already).
Views design
-
CommonListsMixin A simply ContextMixin class that gets all topics (Album) and all owners. Will be used by other View classes.
-
IndexView Uses CommonListsMixin mixin to fill the context about topics (Album) and owners for the left navigation bar. It also prints all the photos if the route starts with
/api
. -
TopicView Uses CommonListsMixin mixin to fill the context about topics (Album) and owners for the left navigation bar. It outputs all the photos of a given topic (hashtag). It also prints the data via API. If the route contains
.../7
it searches for the 7-most-rated photos of current album. -
OwnerView Much like TopicView, but for the owners.