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Modify state.rs

Let's modify some files.

Start in the src/state.rs file.

Change 1 - Global Configuration​

First, replace the 4 instances of the word State with Config to reflect the nature of what is being done to the contract. i.e. global configuration.

It should look like this:

use schemars::JsonSchema;
use serde::{Deserialize, Serialize};

use cosmwasm_std::Addr;
use cw_storage_plus::Item;

#[derive(Serialize, Deserialize, Clone, Debug, PartialEq, Eq, JsonSchema)]
pub struct Config {
    pub count: i32,
    pub owner: Addr,
}

pub const Config: Item<Config> = Item::new("config");

Change 2 - Poll Administrator​

Now let's enable a poll administrator with rights to delete polls.

Let's remove the count and owner variables from the struct and assign an admin to an address instead. 

pub struct Config {
    pub admin: Addr
}

Change 3 - Create a Poll struct​

Now let's create a Poll struct

This allows us to store the address of the Poll Creator, the question and the options as a a Vector (list) of pairs (tuples of length 2).

For the poll example above the options vector will look like this: [("Osmosis", 2), ("CUDOS", 1), ("Cosmos Hub", 3)]

The first element of each tuple is the option, and the second element is the count.

#[derive(Serialize, Deserialize, Clone, Debug, PartialEq, JsonSchema)]
pub struct Poll {
    pub creator: Addr,
    pub question: String,
    pub options: Vec<(String, u64)>,
}

Change 4 - Create a Ballot struct​

In order to keep track of who has already voted and what they voted for, we create another struct.

This simply stores the option voted for. 

#[derive(Serialize, Deserialize, Clone, Debug, PartialEq, JsonSchema)]
pub struct Ballot {
    pub option: String,
}

Change 5 - Use Map​

Now we have defined our structs but we need to store multiple items.

Each poll is going to need a unique identifier to act as a key for values. The Map data structure interface is provided by cw-storage-plus.

Each poll will have UUID that can be generated client side as a String key.

  1. Polls Map
use cw_storage_plus::Item;

// TO THIS

use cw_storage_plus::{Item, Map};

This allows the import of an Item and Map from cw-storage-plus. 

pub const CONFIG: Item<Config> = Item::new("config");

// A map with a String key and Poll value.
// The key will be a UUID generated clientside
// Storage parameter for Storage key is "polls"
pub const POLLS: Map<String, Poll> = Map::new("polls");
  1. Ballot Map
pub const POLLS: Map<String, Poll> = Map::new("polls");
pub const BALLOTS: Map<(Addr, String), Ballot> = Map::new("ballots");
tip

Great work! 🎉​