App Engine application for the Udacity training course.

• App Engine

• Python

• Google Cloud Endpoints

1. Update the value of application in app.yaml to the app ID you have registered in the App Engine admin console and would like to use to host your instance of this sample.
2. Update the values at the top of settings.py to reflect the respective client IDs you have registered in the Developer Console.
3. Update the value of CLIENT_ID in static/js/app.js to the Web client ID
4. (Optional) Mark the configuration files as unchanged as follows: $ git update-index --assume-unchanged app.yaml settings.py static/js/app.js
5. Run the app with the devserver using dev_appserver.py DIR, and ensure it's running by visiting your local server's address (by default localhost:8080.)
6. (Optional) Generate your client library(ies) with the endpoints tool.
7. Deploy your application.

Sessions are implemented with a "has-a" relationship with conference. In particular, a conference can have 0 or more sessions, and each session must be associated with one conference. This follows the intuition that a session wouldn't occur in multiple conferences and any conference would likely have multiple sessions. This relationship is specified by the conference attribute associated with each session, which takes a KeyProperty(kind = Conference) data type. Speakers are implemented as a property of sessions. In particular, each session has a speaker. Duration of the session is a float property, representing the number of hours.

There are also SessionForm and SessionForms objects which represent protorpc message versions of the Session database objects suitable for passing session information back and forth to the front end via the session API.

##Two additional queries (Task 3)

One additional query (getConferenceSessionByDuration) checks to return sessions falling within a particular duration. It also accepts a conference key, so each query only returns sessions within that particular conference.

The second query is getConferencesByCity which returns all of the conferences available in a particular city.

The question asks about the problem with implementing a query for non-workshops sessions before 7 PM. The problem with implementing the query is that the datastore places a limitation on queries such that you cannot use inequality filters on multiple properties. Here, we are trying to do 2 inequality filters: a '!=' filter on Session type and a '<=' on session time. Trying to do this will raise an exception.

My solution to this problem is to perform the two queries separately, and then get the intersection of the two resulting arrays of Session entities. I take the entity keys of the resulting two session lists from the two queries, convert them to python Sets, get the intersection, get the full session objects from the keys and return the session forms. The solution is implemented in the getSessionsNotEqualTypeBeforeTime endpoint method.