Angular with Firebase: How to ignore a field in a query

I am curious to see if my current structure is compatible with Firebase, or if I need to make adjustments. Let's take a look at an example using the "/rooms" endpoint, which contains an array of Room objects:

export class Room {
    id: number;
    password: string;
    state: number;
    messages: Message[] = [];
}

And now let's consider the Message class:

export class Message{
    author: string;
    message: string;
    playerExcluded: string;

}

My goal is to load a room without a password (which should be feasible) and where message.playerExcluded does not equal firebase.auth().currentUser.uid (this part seems more challenging).

This setup essentially means that each user will have access to all messages except those from which they are excluded. One potential solution could involve loading fields like id and state directly from the Room object first, followed by another query to load Messages, but this approach may not be optimal.

Is it realistic to achieve this in a single query, or would it be too complicated? Any suggestions on how to go about this?

Answer №1

As per the guidelines provided by Firebase, it is recommended to flatten your data. Since you are already following this practice, your data structure seems appropriate. This approach will require performing two queries in order to retrieve messages.


In accordance with Firebase documentation:

When data is divided into separate paths through denormalization, it can be efficiently retrieved in separate calls as needed. Consider this flattened structure:

{
  // The 'chats' section contains metadata about each conversation
  // stored under a unique chat ID
  "chats": {
    "one": {
      "title": "Historical Tech Pioneers",
      "lastMessage": "ghopper: Relay malfunction found. Cause: moth.",
      "timestamp": 1459361875666
    },
    "two": { ... },
    "three": { ... }
  },

  // Members of conversations are easily accessible
  // and stored based on chat conversation ID
  "members": {
    // More details on indices like this are discussed below
    "one": {
      "ghopper": true,
      "alovelace": true,
      "eclarke": true
    },
    "two": { ... },
    "three": { ... }
  },

  // Messages are kept separate for quick iteration of other data
  // but still remain easy to paginate and query, organized by chat
  // conversation ID
  "messages": {
    "one": {
      "m1": {
        "name": "eclarke",
        "message": "The relay seems to be malfunctioning.",
        "timestamp": 1459361875337
      },
      "m2": { ... },
      "m3": { ... }
    },
    "two": { ... },
    "three": { ... }
  }
}

Further information from the documentation states:

By downloading only a small amount of data per conversation, it becomes possible to efficiently iterate through the list of rooms, quickly fetching metadata for room listing or displaying in a user interface. Messages can be fetched separately and displayed in real-time, ensuring a responsive and fast UI experience.

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