Add Accounts

As mentioned in the accounts section, decentralised apps need to track the current state: number of tokens, NFTs transferred, current highest bidder in an auction, orders for a token on a dex etc. These states need to be saved in data storing units on-chain, called accounts.

As you'd have imagined already, we will have to store the state, ie, the number of votes for each candidate of the poll at a given time somewhere. To store this state, we will create and use an account. Accounts are data storing units in Solana. We will explore them more throughout this course.

Open poll.py and you will see this: accounts1

  • Firstly, replace all instaces of "FizzBuzz" from the file and replace it with "Poll"
  • Also remove everything after line 11. Your poll.py should look like this: 

# Poll
# Built with Seahorse v0.2.4
#
# On-chain, persistent Poll!

from seahorse.prelude import *

# This is your program's public key and it will update
# automatically when you build the project.
declare_id('11111111111111111111111111111111')

We will discuss what declare_id does when we discuss Programs. But essentially, the program address is declared within the declare_id. More on it in the next program.

In Seahorse, accounts are represented by classes derived from the Account base class. Let's add a Poll account to the poll.py file which will represent the poll state.


class Poll(Account):
  ethereum: u64
  solana: u64
  polygon: u64
  • The individual fields of the class represent the data which will be stored in the account.
  • In our case these fields are ethereum, solana and polygon that represent the number of votes given to these chains respectively.
  • We use the unsigned u64 data type to store votes as votes can never be negative.

Using the uX notation is not usual to Python. In Python, integers are by default unsigned of default datatype u32 for 32 bit systems, and u64 for 64 bit systems. In case of Seahorse, its necessary to define their underlying data type by using type-annotated fields with no default value. u64 for example corresponds to an unsigned integer with 64 bits.

poll.py will look like this:


from seahorse.prelude import *

declare_id('11111111111111111111111111111111')

class Poll(Account):
  ethereum: u64
  solana: u64
  polygon: u64

Now that we know that accounts will be used to store the poll state on-chain, how can one interact with them to write or modify data?

Instructions!