cra-template-near v0.0.2

Create React App NEAR Template

This template is used to create a NEAR front-end using Create React App. It comes with near-react-hooks.

Getting Started

To get started use this template with Create React App npx create-react-app --template near my-app.

Usage Tutorial

1. create a NEAR Account
2. create a new React app using cra-template-near
3. create a landing page for users to signin
4. add a form to the landing page to wrap NEAR
5. display the wrapped NEAR balance
6. add an unwrap NEAR feature to the form

1. Create a NEAR Account

Checkout the official docs to get started creating a NEAR account here.

2. Create a React Application

The cra-template-near Create React App template sets up a React application preconfigured with near-react-hooks.

To start your project type npx create-react-app --template near wrap-near-app into a terminal. This will create a new directory wrap-near-app based on cra-template-near (see Selecting a template).

3. Create a landing page

To create a landing page we'll edit src/App.js placing a signin button onto the page.

import React from "react";
import { NearSignin } from "near-react-hooks";

export default function App() {
  return (
    <NearSignin
      contractId="wrap.testnet"
      methods={["near_deposit", "near_withdraw"]}
    />
  );
}

• Line 2 - import the NearSignin button from near-react-hooks.
• Line 6-9 - render the NearSignin button onto the page

4. Wrap NEAR on form submit

Next we'll add a form to wrap NEAR.

import React, { useState } from "react";
import { NearSignin, useNearContract } from "near-react-hooks";
import { utils } from "near-api-js";

export default function App() {
  const [amount, setAmount] = useState("0");

  const contract = useNearContract("wrap.testnet", {
    changeMethods: ["near_deposit"],
  });

  const handleSubmit = (event) => {
    event.preventDefault();
    contract.near_deposit({
      args: {},
      amount: utils.format.parseNearAmount(amount),
    });
  };

  return (
    <>
      <NearSignin
        contractId="wrap.testnet"
        methods={["near_deposit", "near_withdraw"]}
      />
      <form onSubmit={handleSubmit}>
        <input
          type="number"
          value={amount}
          onChange={({ target }) => setAmount(target.value)}
        />
        <button>Wrap NEAR</button>
      </form>
    </>
  );
}

• Line 8-10 - define a NEAR smart contract interface
• Line 26-33 - form to collect the amount of NEAR to wrap from user input
• Line 14-17 - call the near_deposit method attaching amount of NEAR for wrapping

5. View wrapped balance on mount

import React, { useEffect, useState } from "react";
import { NearSignin, useNearContract, useNearWallet } from "near-react-hooks";
import { utils } from "near-api-js";

export default function App() {
  const [balance, setBalance] = useState(null);
  const [amount, setAmount] = useState("0");

  const wallet = useNearWallet();
  const accountId = wallet.getAccountId();
  const contract = useNearContract("wrap.testnet", {
    changeMethods: ["near_deposit"],
    viewMethods: ["ft_balance_of"],
  });

  useEffect(() => {
    contract
      .ft_balance_of({ account_id: accountId })
      .then((balance) => utils.format.formatNearAmount(balance))
      .then(setBalance);
  }, [contract, accountId]);

  const handleSubmit = (event) => {
    event.preventDefault();
    contract.near_deposit({
      args: {},
      amount: utils.format.parseNearAmount(amount),
    });
  };

  return (
    <>
      <NearSignin
        contractId="wrap.testnet"
        methods={["near_deposit", "near_withdraw"]}
      />
      <p>Current Wrapped Balance: {balance}</p>
      <form onSubmit={handleSubmit}>
        <input
          type="number"
          value={amount}
          onChange={({ target }) => setAmount(target.value)}
        />
        <button>Wrap NEAR</button>
      </form>
    </>
  );
}

• Line 13 - add ft_balance_of to the contract interface
• Line 16-21 - call the ft_balance_of method passing the account_id argument
• Line 19 - receive the wrapped NEAR balance and convert yoctoNEAR to NEAR.
• Line 37 - display the balance

6. Unwrap NEAR on form submit

import React, { useEffect, useState } from "react";
import { NearSignin, useNearContract, useNearWallet } from "near-react-hooks";
import { utils } from "near-api-js";

export default function App() {
  const [balance, setBalance] = useState(null);
  const [amount, setAmount] = useState("0");
  const [method, setMethod] = useState("wrap");

  const wallet = useNearWallet();
  const accountId = wallet.getAccountId();
  const contract = useNearContract("wrap.testnet", {
    changeMethods: ["near_deposit", "near_withdraw"],
    viewMethods: ["ft_balance_of"],
  });

  useEffect(() => {
    contract
      .ft_balance_of({ account_id: accountId })
      .then((balance) => utils.format.formatNearAmount(balance))
      .then(setBalance);
  }, [contract, accountId]);

  const handleSubmit = (event) => {
    event.preventDefault();
    if (method === "wrap") {
      contract.near_deposit({
        args: {},
        amount: utils.format.parseNearAmount(amount),
      });
    }

    if (method === "unwrap") {
      contract.near_withdraw({
        args: {
          amount: utils.format.parseNearAmount(amount),
        },
        amount: 1,
      });
    }
  };

  return (
    <>
      <NearSignin
        contractId="wrap.testnet"
        methods={["near_deposit", "near_withdraw"]}
      />
      <p>Current Wrapped Balance: {balance}</p>
      <form onSubmit={handleSubmit}>
        <select
          defaultValue={method}
          onChange={({ target }) => setMethod(target.value)}
        >
          <option value="wrap">Wrap NEAR</option>
          <option value="unwrap">Unwrap NEAR</option>
        </select>
        <input
          type="number"
          value={amount}
          onChange={({ target }) => setAmount(target.value)}
        />
        <button>{method} NEAR</button>
      </form>
    </>
  );
}

• Line 13 - add near_withdraw to the contract interface
• Line 24-41 - check if wrap or unwrap is selected then call either near_deposit or near_withdraw