JQL_retention.js

/* globals params */
/* Retention.jql
 *
 * A JQL query that gets retention data over a time period.
 *
 * Params:
 *
 *  - fromDate: new Date
 *  - toDate: new Date
 *  - startEvents: [ jql.types.Event ]
 *
 *    A series of events which together are the entrance condition. A
 *    user must complete ALL of these events to be counted as a member
 *    of the group we are measureing retention for. In other words,
 *    they must do EventA AND EventB.
 *
 *  - retentionEvents: [ jql.types.Event ]
 *
 *    A set of events of which any can count sa the retention condition.
 *    A user must complete ANY of these events to be counted
 *    as retained on a given interval. In other words, they must do
 *    EventA OR EventB.
 *
 *  - retentionInterval: Number (milliseconds)
 *
 *    The interval within which a user must complete an action to be
 *    counted as retained. For instance, a retention interval of
 *    1 day (8640000) means a user must complete one of the retentionEvents
 *    in a 1 day interval to be counted as retained.
 *
 *  - retentionBuckets: [ Number ]
 *
 *    The number of intervals after the fromDate on which to measure retention.
 *    For instance, if you have an interval of 1 day and retention buckets of
 *    [0, 1, 7, 14, 30], this will return the retention for D0, D1, D7, D14,
 *    and D30.
 */

import RetentionState from '../helpers/RetentionState'
import * as DateHelper from '../helpers/DateHelper'

function main () {
  // Normalize from and to date to follow standard Mixpanel
  // date format without hours (i.e. 2016-04-26)
  params.fromDate = DateHelper.formatDate(params.fromDate)
  params.toDate = DateHelper.formatDate(params.toDate)

  return Events({
    from_date: params.fromDate,
    to_date: params.toDate,
    event_selectors: params.startEvents.concat(params.retentionEvents)
  })
  // Build retention dictionaries for all users that had
  // events during the time frame
  .groupByUser(function (state, events) {
    state = RetentionState.fromObject(state, params)
    state.consume(events)
    state.ensureAllBucketsHaveStatus()
    return state.toObject()
  })
  // Filter out users who never completed the Start series
  // of retention events
  .filter(function (item) { return item.value.startEpoch })
  // Group users by when they completed the Start series
  // of retention events
  .groupBy([function (item) { return item.value.startEpoch }], function (accums, items) {
    var res = {}
    var i = 0
    var j = 0
    var index = 0
    for (i = 0; i < params.retentionBuckets.length; i++) {
      index = params.retentionBuckets[i].toString()
      res[index] = {}
      res[index].converted = 0
      res[index].total = 0
      for (j = 0; j < items.length; j++) {
        if (items[j].value.retention[index] === RetentionState.STATUS.PRESENT) {
          res[index].converted++
          res[index].total++
        } else if (items[j].value.retention[index] === RetentionState.STATUS.ABSENT) {
          res[index].total++
        }
      }
      for (j = 0; j < accums.length; j++) {
        res[index].converted += accums[j][index].converted
        res[index].total += accums[j][index].total
      }
    }
    return res
  })
  .reduce(function (accums, items) {
    var data = {}
    var item, index
    for (var i = 0; i < accums.length; i++) {
      for (var key in accums[i]) {
        data[key] = accums[i][key]
      }
    }
    for (i = 0; i < items.length; i++) {
      for (var j = 0; j < params.retentionBuckets.length; j++) {
        index = params.retentionBuckets[j]
        if (!data[index]) {
          data[index] = {}
        }
        item = items[i].value[params.retentionBuckets[j]]
        if (item.total > 0) {
          data[index][DateHelper.formatDate(new Date(items[i].key[0]))] = parseFloat((item.converted / item.total * 100).toFixed(2))
        }
      }
    }
    return data
  })
}

export default main