Rust Smart Contracts Development Diary (10-2): Sputnik DAO Factory Contract Analysis

This article will provide an in-depth interpretation of the design and implementation of the Sputnik DAO platform factory model (sputnikdao-factory).

1. Sputnik-DAO Factory Contract

Sputnik-DAO adopts a creation-based factory design pattern to achieve the unified creation and management of the decentralized autonomous organization (DAO) on the platform.

The source code repository for the corresponding contract is located at:

2. Introduction to DAPP Module Functions

The DAPP page of the Sputnik DAO platform displays the created DAO instance object (Sputnikdaov2 contract ). As of March 2022, the most active DAO on the platform is news.sputnik-dao.near, with 3051 proposals either voting or completed.

All DAO instance contracts created on the Sputnik DAO platform are uniformly deployed under its sub-accounts by the sputnik-dao.near account ( and the sputnikdao-factory contract ), for example:

• pcp.sputnik-dao.near
• test-dao-bro.sputnik-dao.near
• blaqkstereo.sputnik-dao.near

Organizations can publicly call the create() method of the sputnikdao-factory smart contract in the NEAR mainnet to create new DAO instances.

3. Interpretation of sputnikdao-factory Contract Code

3.1 Create DAO

The contract status of sputnikdao-factory mainly consists of two parts:

rust pub struct SputnikDAOFactory { factory_manager: FactoryManager, daos: UnorderedSet, }

• factory_manager: Provides methods to create/delete/update DAO instances.
• daos: records the NEAR account address of the created DAO instance

create() method definition:

rust #[payable] pub fn create(&mut self, name: AccountId, args: Base64VecU8) { let account_id: AccountId = format!('{}.{}', name, env::current_account_id()) .parse() .unwrap(); let callback_args = serde_json::to_vec(\u0026json!({ 'account_id': account_id, 'attached_deposit': U128(env::attached_deposit()), 'predecessor_account_id': env::predecessor_account_id() })) .expect('Failed to serialize'); self.factory_manager.create_contract( self.get_default_code_hash(), account_id, 'new', &args.0, 'on_create', &callback_args, ); }

The specific implementation of factory_manager.create_contract:

rust pub fn create_contract( &self, code_hash: Base58CryptoHash, account_id: AccountId, new_method: &str, args: [u8], callback_method: &str, callback_args: &[u8], ) { // Load contract code // Create Promise // Create Account // Transfer // Deploy contract
// Call the initialization function // Set Callback }

on_create callback function:

rust #[private] pub fn on_create( &mut self, account_id: AccountId, attached_deposit: U128, predecessor_account_id: AccountId, bool { if near_sdk::is_promise_success)( { self.daos.insert)\u0026account_id(; true } else { Promise::new)predecessor_account_id(.transfer)attached_deposit.0(; false } }

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) 3.2 Update DAO

update###( method:

rust pub fn update)&self, account_id: AccountId, code_hash: Base58CryptoHash( { let caller_id = env::predecessor_account_id)(; assert!) caller_id == self.get_owner(( || caller_id == account_id, 'Must be updated by the factory owner or the DAO itself' ); assert!) self.daos.contains(&account_id(, 'Must be contract created by factory' ); self.factory_manager .update_contract)account_id, code_hash, 'update'(; }

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4. Sputnik-DAO Factory Contract Security Analysis

Mainly ensure security from the following aspects:

• Permission control: the view method does not modify state variables
• The privileged function can only be executed by the owner.
• Reasonable error handling mechanism

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