Pushing Surveys from the Server to the Phone


In addition to periodic surveys that are generated through local processing on the phone, the server can also push surveys to the phone. These pushes can be periodic (e.g. every x hours, at certain times, e.g. at 21:00 UTC every day, or based on travel patterns from users).

The basic components of a server-generated survey push are:

  1. the selection of users who receive the survey
  2. the survey

Once the selection and the survey specs have been determined, the survey can be pushed to users using bin/push/send_survey.py

Selection

The bin/push/send_survey.py help message lists the ways to select users. In addition to the standard email and uuid options, you can also specify a query_spec that identifies users based on their travel patterns. The existing codebase includes three sample queries (emission/net/ext_service/push/sample.specs/query):

  1. platform: which matches queries for a particular platform (android v/s ios)
  2. point_count: which counts the number of times a particular user has traversed a georegion
  3. trip_metrics: which uses trip related information such as distance, count and duration

The code corresponding to these specs is at emission/net/ext_service/push/query - we welcome contributions of other query specs that you have found useful.

Survey

The survey spec is used to specify the survey to push. The spec is similar to the one used on the phone although a fun fact is that this came first :) Again, you specify the URL of the survey and the field that the uuid is populated into. As before, the examples are at emission/net/ext_service/push/sample.specs/push