Dynamically Loading Antelope Smart Contracts

What is the Contract Kit?

The Contract Kit is a set of tools designed to help developers interact with smart contracts on Antelope-based blockchains. It allows instantiation of Contract objects in frontend applications to assist with interactions against specific smart contracts. Its primary area of focus is around the easy create actions and the ability to read data from the contract.

Adding the Contract Kit

In order to utilize the Contract Kit in a web application, the package simply needs to be added to the project using your preferred package manager:

yarn add @wharfkit/contract

or

npm install @wharfkit/contract

The additional dependencies that the Contract Kit requires will automatically be installed.

The ContractKit Factory Class

The ContractKit class offered by the Contract Kit package is a factory method that’s capable of dynamically loading and producing Contract objects. Each Contract object represents an instance of a specific smart contract on the blockchain. With this object, an application can access data from the contract’s tables, create actions to use with the Session Kit, and utilize other methods to help the application interact with the smart contract.

If dynamically loading contracts, an instance of the ContractKit must first be established within the application. The only argument required to create an instance will be an APIClient that allows the kit to communicate with the blockchain.

import { ContractKit } from "@wharfkit/contract"

const contractKit = new ContractKit({
  client: new APIClient("https://jungle4.greymass.com"),
})

The ContractKit variable is now a ready-to-use instance of the kit, and can be used to dynamically load contracts into the application.

Loading a Contract

With the kit established, the application can now create an instance of a Contract using the load method of the ContractKit. In this example, the code will load the eosio.token contract from the Jungle 4 blockchain.

const contract = await contractKit.load("eosio.token")

The account name where the contract is deployed needs to be passed as a parameter to the call. The result of this call will be a Contract object that is ready to use within the host application.

More…

With an instance of a Contract now loaded, the application can make use of it to either:

• Create actions for use in transact
• Load data from the contract tables

Stay tuned as more guides, documentation and example codebases are added, or ask questions in the Github discussion board for WharfKit!