An upgradable wrapper around the Polymesh Runtime API.

This allows contracts to use a stable API that can be updated to support each major Polymesh release.

The ./upgrade_tracker contract is an optional feature for easier upgrades. It allows multiple contracts to use upgradable APIs without having to have "admin" support in each contract.

Build the wrapped API contract.

Install cargo-contract. cargo install cargo-contract --force

Build the contract: cargo +nightly contract build --release

Contract file needed for upload ./target/ink/polymesh_ink.contract.

Example contract that uses the Polymesh Ink! API

Cargo.toml: ```toml [package] name = "example_contract" version = "1.0.0" authors = [""] edition = "2021" publish = false

[dependencies] inkprimitives = { version = "3.0", default-features = false } inkprelude = { version = "3.0", default-features = false } inkmetadata = { version = "3.0", default-features = false, features = ["derive"], optional = true } inkenv = { version = "3.0", default-features = false } inkstorage = { version = "3.0", default-features = false } inklang = { version = "3.0", default-features = false } inklangcodegen = { version = "3.0", default-features = false }

scale = { package = "parity-scale-codec", version = "3", default-features = false, features = ["derive"] } scale-info = { version = "2", default-features = false, features = ["derive"], optional = true }

polymesh-ink = { version = "0.5.3", path = "../../", default-features = false, features = ["as-library", "tracker", "always-delegate"] }

[lib] name = "example_contract" path = "lib.rs" crate-type = ["cdylib"]

[features] default = ["std"] std = [ "inkprimitives/std", "inkmetadata/std", "inkenv/std", "inkstorage/std", "ink_lang/std", "scale/std", "scale-info/std", "polymesh-ink/std", ] ink-as-dependency = [] ```

lib.rs: ``rust //! Example contract for upgradablepolymesh-ink` API.

![cfgattr(not(feature = "std"), nostd)]

extern crate alloc;

use ink_lang as ink;

use polymesh_ink::*;

[ink::contract(env = PolymeshEnvironment)]

pub mod example_contract { use crate::*; use alloc::vec::Vec;

/// Exchange contract using the Polymesh Ink! API.
#[ink(storage)]
pub struct ExampleContract {
    /// Upgradable Polymesh Ink API.
    api: PolymeshInk,
}

/// The contract error types.
#[derive(Debug, scale::Encode, scale::Decode)]
#[cfg_attr(feature = "std", derive(scale_info::TypeInfo))]
pub enum Error {
    /// PolymeshInk errors.
    PolymeshInk(PolymeshError),
    /// Upgrade error.
    UpgradeError(UpgradeError)
}

impl From<PolymeshError> for Error {
    fn from(err: PolymeshError) -> Self {
        Self::PolymeshInk(err)
    }
}

impl From<UpgradeError> for Error {
    fn from(err: UpgradeError) -> Self {
        Self::UpgradeError(err)
    }
}

/// The contract result type.
pub type Result<T> = core::result::Result<T, Error>;

impl ExampleContract {
    /// Instantiate this contract with an address of the `logic` contract.
    ///
    /// Sets the privileged account to the caller. Only this account may
    /// later changed the `forward_to` address.
    #[ink(constructor)]
    pub fn new(tracker: UpgradeTrackerRef) -> Self {
        Self {
            api: PolymeshInk::new_tracker(tracker),
        }
    }

    /// Update the `polymesh-ink` API using the tracker.
    ///
    /// Anyone can pay the gas fees to do the update using the tracker.
    #[ink(message)]
    pub fn update_polymesh_ink(&mut self) -> Result<()> {
        self.api.check_for_upgrade()?;
        Ok(())
    }

            // Simple example of using the Polymesh Ink! API.
    #[ink(message)]
    pub fn create_asset(&mut self, name: Vec<u8>, ticker: Ticker, amount: Balance) -> Result<()> {
        self.api
            .asset_create_and_issue(AssetName(name), ticker, AssetType::EquityCommon, true, Some(amount))?;
        Ok(())
    }
}

} ```

Setup.

1. (Optional) Build and deploy the upgrade tracker contract ./upgrade_tracker/.
2. Build and upload (don't deploy) the wrapped API contract ./target/ink/polymesh_ink.contract.
3. Build and deploy an example contract from ./examples/. Use the code hash from step #2 and the tracker contract address from step #1 if used.

Usable

The update_polymesh_ink or update_code_hash calls can be used to update the code hash for the Polymesh Ink! API.