ConferenceCentral

Application for Udacity Full Stack Nanodegree - Project 4

Products

• App Engine

Language

• Python

APIs

• Google Cloud Endpoints

AppEngine ID

fsnd-p4-conference-1153

ConferenceCentral AppSpot URL

https://fsnd-p4-conference-1153.appspot.com

EndPoints API Explorer URL for ConferenceCentral

https://fsnd-p4-conference-1153.appspot.com/_ah/api/explorer

Whats Included?

• ConferenceCentral

  • static
    • Contains static resources like css, js, images, html partials etc.
  • templates
    • Contains index.html page which is rendered as template by python server
  • app.yaml
    • Configuration about application dependencies
  • cron.yaml
    • Configuration for cron jobs
  • index.yaml
    • The indexes information, generated automatically.
  • conference.py
    • All the endpoints for conference central app
  • main.py
    • The methods to handle email confirmations, announcements
  • models.py
    • Definitions of ProRPC Messages, classes for Datastore Entities
  • settings.py
    • Contains Client ID for appspot
  • utils.py
    • Handles utility methods like getting user information etc.

Setup Instructions

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. Generate your client library(ies) with the endpoints tool.
7. Deploy your application.

Task 1 Explanation

Entities Defined for Task 1

These entities are added to models.py

• Session

Session is defined as a child entity of conference. It has further information about its name, speaker, highlights, start time, duration and date. It is made child entity of conference because it will be easy to retrieve all the sessions for a conference.

• name: It stores the session's name information. String type

• websafeSpeakerKey: It stores the unique id of speaker for this session. speaker's detailed information is stored in Speaker kind. String type

• highlights: This is repeated property which can store multiple highlights of a session. It can be used for searching sessions with specific highlights. All values are stored as String types.

• startTime: Indicates the starting time of session. It is stored as integer which takes values in military hours notation e.g. 1705

• duration: It is an integer which stores the session duration in minutes.

• date: This property is of type date. Stores the date of the session. Format: yyyy-mm-dd

• Speaker

Speaker entity is defined with its properties as name, interests, organization. Speaker's websafe key is part of Session attributes. Speaker is chosen to be as a separate entity to keep further information about speaker and flexibility for potential future changes to speaker information. It can also help in future if the separate speaker profiles are introduced in ConferenceCentral app.

• name: Name of the speaker. It is a String property.
• interests: List of interests. Stored as repeated string property.
• organization: Name of speaker's organization. String property.

Methods Defined for Task 1

These methods have been added to conference.py

• getConferenceSessions

Retrieves all the sessions in a conference based on websafeConferenceKey passed from client and returns as SessionForms object containing resulting sessions. websafeConferenceKey is used as ancestor key to filter the sessions.

• getConferenceSessionsByType

Retrieves all the sessions in a conference based on websafeConferenceKey and start time passed from client and returns as SessionForms object containing resulting sessions. websafeConferenceKey is used as ancestor key to filter the sessions.

• getSessionsBySpeaker

Retrieves all the sessions based on speaker information passed from client and returns as SessionForms object containing resulting sessions.

• createSession

Creates the session using information passed from client which contains name, conference key, speaker key, highlights, start time, duration and date. conference key is used as parent key to add new session. startTime input parameter takes military hours notation time format e.g. 1705.

Task 2 Explanation

Following methods have been implemented for task 2.

• addSessionToWishlist

  • Calls _updateSessionWishlist method with reg=True parameter which implements functionality of both adding to wishlist and deleting from wishlist, which updates the wishlist property of Profile entity in datastore by adding the session ID in it.

• deleteSessionInWishlist

  • Calls _updateSessionWishlist method with reg=False which implements functionality of both adding to wishlist and deleting from wishlist, which updates the wishlist property of Profile entity in datastore by adding the session ID in it.

• getSessionsInWishlist

  • Gets all the sessions in user's wishlist

Task 3 Explanation

Following endpoints have been added as 2 additional queries which generate two additional indexes.

• getSessionsByStartTimeAndDuration

Queries the sessions and filters based on the startTime and duration provided by client. Checks for the sessions which start at or after the time provided by client and have requested duration. Returns SessionForms object with resulting sessions. It generates following index in index.yaml file.

   - kind: Session
     properties:
     - name: duration
     - name: startTime

• getSessionsByMinStartTimeDurationHighlights

Queries the sessions and filters based on the startTime, duration and highlights provided by client. Checks for the sessions which start at or after the time provided by client, have requested duration and highlights. Returns SessionForms object with resulting sessions. It generates following index in index.yaml file

   - kind: Session
     properties:
     - name: duration
     - name: highlights
     - name: startTime

Solution for multiple inequality query problem

The problem with querying for sessions which do not have type workshop and start before 7 PM is that it cannot be queried in one go. The reason is that the App Engine does not not allow multiple inequalities on different properties in one query. When attempted to do so, it throws an exception. AppEngine only allows multiple inequalities on one property. So in order to handle this scenario, the implemented solution first filters the sessions on type and fetches all the sessions which are not the type of Workshop from datastore, and then the result is iterated to check if each session meets the second inequality condition of starting before 7 PM. Later, the filtered results are returned to client as SessionForms ProtoRPC message containing list of filtered sessions.

Task 4 Explanation

getFeaturedSpeaker

Gets the memcache entry for featured speaker which is updated when a new session is added and number of sessions of that user are more than one This has been implemented using task queue. Call to this task queue is made when the session is created.