Running balance alongside transactions

[fmorency]

As a user, I need the capability to display a running balance column alongside my transaction records. This feature would help me easily track the evolving balance of my account as I make transactions, allowing for a quick and accurate assessment of my financial standing.

Relates #143

[stanleyjones]

I've spent the morning looking into this issue and coming up with a few ways we could do it. Currently, Alberto does something like this:

1. Fetch the 11 latest account events
2. Fetch each transaction from its event
3. Show the first 10 transactions
4. If there are more than 10 transactions, show a "next" button
5. Repeat when the user clicks the button, each time fetching 1 more than necessary to show

We have a few options:

• (A) Fetch all the account events and transactions from the beginning and calculate a running balance from 0
• (B) Fetch all the account events but delay fetching the transaction until it needs to be shown
• (C) Fetch the current balance at the beginning and reverse transactions to get a running balance toward 0
• (D) Calculate running balance to the back-end (probably events) and only display them in the front-end

Am I missing any ideas?

cc @fmorency @jgryffindor

[stanleyjones]

• (E) Fetch events and transactions async (not dependent on user interaction) and cache them somewhere more persistent than browser memory, e.g IndexedDB

[fmorency]

@stanleyjones Check out #146, it contains things that will be useful for this task, i.e., useAllTransactionsList. You should be able to implement (A) or (B) with it.

We can look into (D) and (E) if/when we need to scale.

The only edge-case is the treasury which needs to start from the genesis balance and not 0.

[fmorency]

@stanleyjones You're also welcome to comment/improve on that PR!