Integrate Firebase Realtime DB & fetch real data for home & detail screen.

[pocha]

Realtime DB data structure here

For our case, the data need to be like

users: {
  <id>: {
      tags: {tag_id1, tag_id2 ..}
   }
}

tags: {
  <tag_id>: {
     name: _string_
     owner: _user_id_
     shared_with: { user_id1, user_id2},
     expenses: {expense_id1, expense_id2}
  }
}

expenses: {
   <expense_id>: {
       timestamp: _number_,
       from: user_id,
       to: user_id,
       amount: _number_,
       tags: {tag_id1, tag_id2}
   }
}

Populate some data manually in Realtime DB for a user including tag + expenses & show the data in home & detail screen

For reading data from the Firebase DB, use onValue() rather using get() as explained here

[pocha]

• Home page init should

  • listen on user tags
    • onChildAdded to add new expenses on the UI
    • onChildRemoved to remove the tag from the UI
    • for each tag - listen on filtered expenses for the month & add them to create the current month aggregated sum & show on the UI

• Detail page init should

  • listen on the expenses under the tag
  • onChildAdded to add the new expense in the Expenses UI. Also update the monthly sum for the month for the UI
  • onChildRemoved to remove the expense from the UI & reduce the monthly sum.