conversation-action-log-water.js

const ARG_WATER_VOLUME = 'water_volume';

//...
class Conversation {
  
  //...
  
  actionLogWater() {
      //Get argument extracted by Dialogflow
      let waterToLog = this.dialogflowApp.getArgument(ARG_WATER_VOLUME);
      //Save logged water into Firebase Realtime Database
      this.waterLog.saveLoggedWater(this._getCurrentUserId(), waterToLog);
      //Load sum of logged water for current user and reply user 
      //with how much water he or she logged so far. 
      //End the conversation.
      return this.waterLog.getLoggedWaterForUser(this._getCurrentUserId())
          .then(loggedWater => {
              this.dialogflowApp.tell(
                  util.format(Str.WATER_LOGGED_NOW,
                      waterToLog.amount,
                      waterToLog.unit,
                      loggedWater
                  )
              );
          });
  }
}