Web3 Dubai MetaMask Workshop | DevsDay.ru

IT-блоги Web3 Dubai MetaMask Workshop

dev.to 17 ноября 2022 г. Eric Bishard


Web3 Dubai MetaMask Workshop (Follow Along)

Workshop GitHub Repo

Prerequisites:

  • NodeJS & NPM
  • Code Editor
  • Git & GitHub account
  • MetaMask Extension Installed
  • Knowledge of JavaScript, TypeScript and React (is a plus)
  • Eagerness to learn NextJS, Solidity smart contracts, Truffle and Ganache
npm i truffle ganache -g

Getting Started

Welcome to the Web3 Dubai Metamask Workshop, to get started, please clone the workshop repo on your machine and checkout the start branch:

git clone https://github.com/metamask/web3-dubai-mm-workshop && 
cd web3-dubai-mm-workshop && 
git checkout start && npm i

With our repo cloned and our dependencies installed we should take minute to discuss our choices for the decisions and architecture of this web3 project.

  • A mono repo using Turbo
    • Incremental bundler/build system optimized for mono repos, JS & TS
  • Seperating our blockchain and web projects
  • React & NextJS
  • Truffle & Ganache

At this point, we have a pretty solid framework to build Web3 applications with, is it a bit opinionated, yes, is it different? I would say that if you are a web2 developer just getting started with Web3 these tools should feel familliar, we are using ReactJS, JS & TS and we have at the least dropped you off at the doorstep of a pretty solid way to build a fullstack web3 application all in one repo.

Run Our NextJS Project

Let's really quickly just ensure that our frontend NextJS project is running in dev mode. In a new terminal window:

cd apps/web && npm run dev

If everything is working you should see text that says "Let's get started". For now we can exit out of next dev and know that our NextJS frontend is ready when we need it.

If that is working fine we can back up out of that directory because the next time we run the NextJS app it will be from the root with our turbo scripts.

cd ../..

Reviewing our Blockchain App

Rather than spend hours creating our Smart contract for our NFT Tickets, we have provided that for you in this start branch and together we will go over it for the sake of time.

Review in workshop each file:

  • ETHTickets.sol
  • HexStrings.sol
  • 1_initial_migration.js

Building and Running our Project

Let's first get our local blockchain environment up and running, we have several npm scripts setup to help us build and run our project locally.

let's build our contracts and generate types that we can use in our NextJS app.

From the root for the project run:

npm run build

For running a local instance of Truffle and Ganache to generate accounts, private keys for use in testing our Web3 app let's open a seperate terminal and run:

npm run local

This will give us some private keys and we can take one of those private keys and import into our MetaMask using the following network information:

  • Network Name: Localhost 9545
  • New RPC URL: http://localhost:9545
  • Chain ID: 1337
  • Currency Symbol: ETH
  • Block explorer URL: we can leave this blank

For our Frontent we can open one more terminal window and run:

npm run dev

Important
We need to pay attention to the output of this command and anytime we rerun this command we will need to get the contract address and copy it into the apps/web/lib/config file.

All of the work from here will be done in our apps/web directory, I should not that all of the dependencies we will be relying on have already been installed:

If needed we can go over those dependencies in the workshop if anyone has any questions, from here we will (together) build the frontend out piece by piece and build everything required to not only connect users via MetaMask to our app, but also do that in a way that is scalable so that if the app were to expand to multiple pages and routes, we would have a solid way to use the wallet state and connection ot the blockchain through that wallet on any page in our dApp.

Connecting Users to MetaMask

We will first need to create a directory in apps/web/components/styledComponents and this is where I will give you some basic styling for our navigation and some general styling we could use throughout our application.

Create: navigation.js with the following code:

import styled from 'styled-components';

export const NavigationView = styled.div`
  padding: 1em;
  border-bottom: 1px solid #FFF;
  background-color: #265C8E;
  color: #FFF;
`;

export const Logo = styled.div`
  display: block;
  display: inline-block;
  line-height: 36px;
  height: 36px;
`

export const Balance = styled.div`
  display: inline-block;
  margin-left: 1em;
`

export const RightNav = styled.div`
  margin-left: auto;
  line-height: 36px;
  height: 36px;
  width: ${props => (props.widthPixel += "px") || "100%"};
`

Create: general.js with the following code:

import styled from 'styled-components';

export const FlexContainer = styled.div`
  display: flex;
  align-self: flex-end;
  flex-direction: row;
  min-width: calc(100vw -2em);
  gap: ${props => props.gap || 0}em;
  row-gap: ${props => props.gap || 0}em;
`;

export const FlexItem = styled.div`
  width: ${props => props.widthPercent || 50}%;
`;

export const Button = styled.button`
  border-radius: 4px;
  border: none;
  background-color: #103164;
  color: #FFF;
  font-size: ${props => props.textSize || 16}px;
  text-transform: uppercase;
  padding: 1em 0.75em;
  display: inline-block;
  margin: 0 1em 0 0;
  cursor: pointer;
  cursor: hand;
  user-select: none;
  &:hover {
    background-color: #244982;
  }
  &:disabled {
    background-color: #244982;
    color: #7697C8;
    cursor: not-allowed;
  }
`

We first need to add a Navigation component and styles, in the apps/web/components directory create a page called Navigation.tsx and add the following code:

import Link from "next/link";

import { Button, FlexContainer, FlexItem, } from "./styledComponents/general";
import { NavigationView, Balance, RightNav, Logo } from "./styledComponents/navigation";
import { SiEthereum } from 'react-icons/si';

export default function Navigation() {

  return (
    <NavigationView>
      <FlexContainer>
        <FlexItem widthPercent={50}>
          <Logo>
            <SiEthereum /> ETH Atlantis
          </Logo>
        </FlexItem>
        <FlexItem widthPercent={50}>
          <RightNav widthPixel={300}>
            <span>MM CONNECT BUTTON</span>
          </RightNav>
        </FlexItem>
      </FlexContainer>
    </NavigationView>
  );
}

With the Styles and basic navigation skeleton in place we need to update our pages/index.tsx inside of our web app.

Update pages/index.tsx and replace the <div>Lets get started</div> with a link to the Navigation component:

import type { NextPage } from "next";
import Head from 'next/head';

import Navigation from '../components/Navigation'

const Mint: NextPage = () => {

  return (
    <div className="mint-tickets">
      <Head>
        <title>ETH Atlantis 2022</title>
        <meta property="og:title" content="The largest underwater Ethereum event in history" key="title" />
      </Head>

      <Navigation />
    </div>
  );
};

export default Mint;

We should see our navigation in the top right corner. We need to replace that text that says "MM CONNECT BUTTON". But first we need to set up two React hooks to listen and provide context for our connected user. Create a new directory in th web app under apps/web/hooks and add the two files and we will go over them:

Add a file named useListen.tsx with the follwoing code:

import { useMetaMask } from "./useMetaMask";

export const useListen = () => {
  const { dispatch } = useMetaMask();

  return () => {
    window.ethereum.on("accountsChanged", async (newAccounts: string[]) => {
      if (newAccounts.length > 0) {
        // uppon receiving a new wallet, we'll request again the balance to synchronize the UI.
        const newBalance = await window.ethereum!.request({
          method: "eth_getBalance",
          params: [newAccounts[0], "latest"],
        });

        dispatch({
          type: "connect",
          wallet: newAccounts[0],
          balance: newBalance,
        });
      } else {
        // if the length is 0, then the user has disconnected from the wallet UI
        dispatch({ type: "disconnect" });
      }
    });
  };
};

Add a file named useMetaMask.tsx with the follwoing code:

import React, { type PropsWithChildren } from "react";

type ConnectAction = { type: "connect"; wallet: string; balance: string };
type DisconnectAction = { type: "disconnect" };
type PageLoadedAction = {
  type: "pageLoaded";
  isMetaMaskInstalled: boolean;
  wallet: string | null;
  balance: string | null;
};
type LoadingAction = { type: "loading" };
type IdleAction = { type: "idle" };

type Action =
  | ConnectAction
  | DisconnectAction
  | PageLoadedAction
  | LoadingAction
  | IdleAction;

type Dispatch = (action: Action) => void;

type Status = "loading" | "idle" | "pageNotLoaded";

type State = {
  wallet: string | null;
  isMetaMaskInstalled: boolean;
  status: Status;
  balance: string | null;
};

const initialState: State = {
  wallet: null,
  isMetaMaskInstalled: false,
  status: "loading",
  balance: null,
} as const;

function metamaskReducer(state: State, action: Action): State {
  switch (action.type) {
    case "connect": {
      const { wallet, balance } = action;
      const newState = { ...state, wallet, balance, status: "idle" } as State;
      const info = JSON.stringify(newState);
      window.localStorage.setItem("metamaskState", info);

      return newState;
    }
    case "disconnect": {
      window.localStorage.removeItem("metamaskState");
      if (typeof window.ethereum !== undefined) {
        window.ethereum.removeAllListeners(["accountsChanged"]);
      }
      return { ...state, wallet: null, balance: null };
    }
    case "pageLoaded": {
      const { isMetaMaskInstalled, balance, wallet } = action;
      return { ...state, isMetaMaskInstalled, status: "idle", wallet, balance };
    }
    case "loading": {
      return { ...state, status: "loading" };
    }
    case "idle": {
      return { ...state, status: "idle" };
    }

    default: {
      throw new Error("Unhandled action type");
    }
  }
}

const MetaMaskContext = React.createContext<
  { state: State; dispatch: Dispatch } | undefined
>(undefined);

function MetaMaskProvider({ children }: PropsWithChildren) {
  const [state, dispatch] = React.useReducer(metamaskReducer, initialState);
  const value = { state, dispatch };

  return (
    <MetaMaskContext.Provider value={value}>
      {children}
    </MetaMaskContext.Provider>
  );
}

function useMetaMask() {
  const context = React.useContext(MetaMaskContext);
  if (context === undefined) {
    throw new Error("useMetaMask must be used within a MetaMaskProvider");
  }
  return context;
}

export { MetaMaskProvider, useMetaMask };

These files respectively listen for changes in the users connection to Metamask and set up a context provider for sharing the wallet state to the components in our app and we can go over each one in the workshop to give more explanation.

With those files in place we wire up our connect, disconnect and display some basic balance information from our connected user.

Let's go back to our Naviagtion component and update it to import these hooks and get everything working:

In the Navigation.tsx file update to the following code:

import Link from "next/link";
import { useListen } from "../hooks/useListen";
import { useMetaMask } from "../hooks/useMetaMask";

import { Button, FlexContainer, FlexItem, } from "./styledComponents/general";
import { NavigationView, Balance, RightNav, Logo } from "./styledComponents/navigation";
import { SiEthereum } from 'react-icons/si';

export default function Navigation() {
  const {
    dispatch,
    state: { status, isMetaMaskInstalled, wallet, balance },
  } = useMetaMask();
  const listen = useListen();

  const showInstallMetaMask =
    status !== "pageNotLoaded" && !isMetaMaskInstalled;
  const showConnectButton =
    status !== "pageNotLoaded" && isMetaMaskInstalled && !wallet;

  const isConnected = status !== "pageNotLoaded" && typeof wallet === "string";

  const handleConnect = async () => {
    dispatch({ type: "loading" });
    const accounts = await window.ethereum.request({
      method: "eth_requestAccounts",
    });

    if (accounts.length > 0) {
      const balance = await window.ethereum!.request({
        method: "eth_getBalance",
        params: [accounts[0], "latest"],
      });
      dispatch({ type: "connect", wallet: accounts[0], balance });

      // we can register an event listener for changes to the users wallet
      listen();
    }
  };

  const handleDisconnect = () => {
    dispatch({ type: "disconnect" });
  };

  const formatAddress = (addr: string) => {
    return `${addr.substr(0, 6)}...${addr.substr(-4)}`
  }

  return (
    <NavigationView>
      <FlexContainer>
        <FlexItem widthPercent={50}>
          <Logo>
            <SiEthereum /> ETH Atlantis
          </Logo>
        </FlexItem>
        <FlexItem widthPercent={50}>
          <RightNav widthPixel={300}>
            {showConnectButton && (
              <Button textSize={10} onClick={handleConnect}>
                {status === "loading" ? "loading..." : "Connect Wallet"}
              </Button>
            )}
            {showInstallMetaMask && (
              <Link href="https://metamask.io/" target="_blank">
                Install MetaMask
              </Link>
            )}
            {wallet && balance && (
              <>
                {isConnected && <Button textSize={10} onClick={handleDisconnect}>Disconnect</Button>}
                <a
                  className="text_link tooltip-bottom"
                  href={`https://etherscan.io/address/${wallet}`} target="_blank"
                  data-tooltip="Open in Etherscan"
                >
                  {formatAddress(wallet)}
                </a>
                <Balance>
                  {(parseInt(balance) / 1000000000000000000).toFixed(2)}{" "}ETH
                </Balance>
              </>
            )}
          </RightNav>
        </FlexItem>
      </FlexContainer>
    </NavigationView>
  );
}

We will go over our changes in the workshop and cover what all of this achieves for us.

At this point we are getting an error because we ave not wrapped the app with a provider, let's go to the apps/web/pages/_app.tsx file and add our MetaMask provider.

In _app.tsx update the code to the following:

import 'normalize.css'
import '../styles/globals.scss'

import type { AppProps } from "next/app";
import { Layout } from "../components/Layout";
import { MetaMaskProvider } from "../hooks/useMetaMask";

function MyApp({ Component, pageProps }: AppProps) {
  return (
    <MetaMaskProvider>
      <Layout>
        <Component {...pageProps} />
      </Layout>
    </MetaMaskProvider>
  );
}

export default MyApp;

We need to make two more changes, one to our apps/web/components/Layout.tsx as this code will determine isMetaMaskInstalled if the ethereum provider exists or is undefined and dispatch the proper actions to our context's reducers.

In the Layout.tsx file update the code to the following:

import { PropsWithChildren, useEffect } from "react";
import { useListen } from "../hooks/useListen";
import { useMetaMask } from "../hooks/useMetaMask";
import { instantiateSdk } from "../lib/MetaMaskSdk";

export const Layout: React.FC<PropsWithChildren> = ({ children }) => {
  const { dispatch } = useMetaMask();
  const listen = useListen();

  useEffect(() => {
    if (typeof window !== undefined) {
      // start by checking if window.ethereum is present, indicating a wallet extension
      const ethereumProviderInjected = typeof window.ethereum !== "undefined";
      // this could be other wallets so we can verify if we are dealing with metamask
      // using the boolean constructor to be explecit and not let this be used as a falsy value (optional)
      const isMetaMaskInstalled =
        ethereumProviderInjected && Boolean(window.ethereum.isMetaMask);

      const local = window.localStorage.getItem("metamaskState");

      // user was previously connected, start listening to MM
      if (local) {
        listen();
      }

      // local could be null if not present in LocalStorage
      const { wallet, balance } = local
        ? JSON.parse(local)
        : // backup if local storage is empty
          { wallet: null, balance: null };

      instantiateSdk();
      dispatch({ type: "pageLoaded", isMetaMaskInstalled, wallet, balance });
    }
  }, []);

  return (
    <div className="app-container">
      {children}
    </div>
  );
};

Finally, we need to add a new file to the apps/web/lib directory called MetaMaskSdk.ts.

Once you have created that file, please add the following code:

import MetaMaskSDK from "@metamask/sdk";

export const instantiateSdk = () => {
  if (typeof window === undefined) {
    return null;
  }

  new MetaMaskSDK();
};

With all of this in place our connect, display and disconnect functionality should work. Let's run our app and try it out. We should now get the option to install if we don't have the MetaMask extension, connect if we do, display balance if we are connected as well as disconnect if we wish.

Add Tickets and Minting

Since our app is based mainly around showing the type of tickets available and giving the user the ability to mint those tickets, we will be adding components directly to the apps/web/pages/index.ts page.

We will first add an array of objects that represent the types of tickets we want to allow users to mint along with their type (GA & VIP), Event Name, Price in ETH using both the actual and hex version of this price. Why both, we want to display the value as well we need the hex value to send to our contract.

On the index.tx page. lets import the ethers (a library for interacting with Ethereum) import just above the Navigation import:

import { ethers } from "ethers";

import Tickets from "../components/tickets/Tickets";
import Navigation from '../components/Navigation';

Next, just under the Mint component declaration add the following code (at line number 8):

  // Get ETH as small number ("0.01" => "10000000000000000")
  const bigNumberify = (amt: string) => ethers.utils.parseEther(amt);

  const ethGa = "0.01";
  const ethVip = "0.02";
  const ethGaHex = bigNumberify(ethGa)._hex;
  const ethVipHex = bigNumberify(ethVip)._hex;
  const tickets = [
    {
      type: "ga",
      event: "ETH Atlantis",
      description: "General Admission Ticket",
      price: ethGa,
      priceHexValue: ethGaHex, // '0x2386f26fc10000' *eserialize.com
    },
    {
      type: "vip",
      event: "ETH Atlantis",
      description: "VIP Ticket",
      price: ethVip,
      priceHexValue: ethVipHex, // '0x470de4df820000' *eserialize.com
    },
  ];

Finally, we will add the actual <TIcket/> component and pass this tickets array to it, just underneath the <Navigation/> component add the following code and until we get that page working we can just comment it out:

      <Tickets tickets={tickets} />

Now we will create a directory named tickets inside apps/web/components and add a file named Tickets.tsx with the following code:

import { useState } from "react";

import { SiEthereum } from 'react-icons/si';

import { Button, FlexContainer, FlexItem, } from "../styledComponents/general";
import { TicketsView, TicketType, TicketTypeText, StyledAlert } from "../styledComponents/tickets";

interface Ticket {
  type: string;
  event: string;
  description: string;
  price: string;
  priceHexValue: string;
}
interface TicketsProps {
  tickets: Ticket[];
}

const TicketTypes: React.FC<Ticket> = ({
  type, event, description, price, priceHexValue,
}) => {

  const [isMinting, setIsMinting] = useState(false);
  const [error, setError] = useState(false);
  const [errorMessage, setErrorMessage] = useState("");

  return (
    <FlexItem>
      <TicketType>
        <TicketTypeText>{description}</TicketTypeText>
        <p>{event}</p>
        <Button disabled={isMinting}>
          <SiEthereum /> {isMinting ? 'Minting...' : 'Mint'} Ticket
        </Button>
        {
          error && (
            <StyledAlert onClick={() => setError(false)}>
              <span>
                <strong>Error:</strong> {errorMessage}
              </span>
            </StyledAlert>
          )
        }
      </TicketType>
    </FlexItem>
  );
};

const Tickets = ({ tickets }: TicketsProps) => {
  return (
    <TicketsView>
      <h1>Ticket Types</h1>
      <FlexContainer gap={1}>
        {tickets.map((ticket) => (
          <TicketTypes key={ticket.type} {...ticket} />
        ))}
      </FlexContainer>
    </TicketsView>
  );
};

export default Tickets;

With this in place we need to add the styled components for the Tickets page which I have already created and will help to render our page with some style.

In the apps/web/components/styledComponents directory create a page called tickets.js and add the following code:

import styled from 'styled-components';

export const TicketsView = styled.div`
  padding: 1em;
`;

export const TicketType = styled.div`
  border-radius: 10px;
  height: 220px;
  padding: 0.01em 1em;
  background-color: #4A7CB1;
  color: #BDCFE2;
  user-select: none;
  -webkit-box-shadow: 3px 7px 33px -14px rgba(17,63,112,1);
  -moz-box-shadow: 3px 7px 33px -14px rgba(17,63,112,1);
  box-shadow: 3px 7px 33px -14px rgba(17,63,112,1);
`;

export const TicketTypeText = styled.h2`
  background-color: #f3ec78;
  background-image: linear-gradient(45deg, #C5ECFF, #8BD8FF);
  background-size: 90%;
  -webkit-background-clip: text;
  -moz-background-clip: text;
  -webkit-text-fill-color: transparent; 
  -moz-text-fill-color: transparent;
`

export const StyledAlert = styled.div`
  border-radius: 5px;
  padding: 0.5em;
  font-size: 10px;
  height: 40px;
  width: 100%;
  word-break: break-word;
  margin: 0.5em 0;
  background-color: #244982;
  strong {
    color: #E2761B;
  }
`

With all of this in place we should see our ticket types show up with minting buttons (that do not work yet) on the page if we navigate to our app on localhost:3000.

Adding Minting Functionality to TicketCategoryDetail Component

With our ticket types in place, we are ready to sell out our event to ETH Atlantis. We need to add some additional code to our Tickets.tsx page which will allow us to interact with our smart contract. If for any reasons you have killed your npm run local or npm run dev processes in the terminal now is a time to get those running and ensure your config.ts file has the right contract address added.

When we are done with this next section we should be able to call our contract's mintNFT function and get some initial feedback indicating our minting process is working in our dApp.

In the Tickets.tsx page, we need to add a few more imports directly above the existing imports we have already added:

import { useState } from "react";
import { useRouter } from "next/router";
import { useMetaMask } from "../../hooks/useMetaMask";
import { ETHTickets__factory } from "blockchain";
import { ethers } from "ethers";
import { config } from "../../lib/config";

import { SiEthereum } from 'react-icons/si';

import { Button, FlexContainer, FlexItem, } from "../styledComponents/general";
import { TicketsView, TicketType, TicketTypeText, StyledAlert } from "../styledComponents/tickets";

These imports will give us access to our connected wallet state, the NextJS router so the we can force a page refresh (only after a successful mint), access to our smart contract through the ETHTickets__factory created by our build which utilizes typechain, the ethers library to get provider and signer for interacting with the blockchain via our contracts methods and the config file that knows the contract address.

Starting on line 28 of the Tickets.tsx file inside our TicketsType component, we need to destructure our wallet state returned by a call to useMetaMask() hook as well define a router with a call to the NextJS useRouter() hook, update that code with the following:

  const { state: { wallet }, } = useMetaMask();
  const router = useRouter();
  const [isMinting, setIsMinting] = useState(false);
  const [error, setError] = useState(false);
  const [errorMessage, setErrorMessage] = useState("");

Directly below the code just added we need to add a function called mintTicket(), add the following code just above the return statement in the TicketsType component:

const mintTicket = async () => {
    setIsMinting(true);

    const provider = new ethers.providers.Web3Provider(window.ethereum);
    // In ethers.js, providers allow you to query data from the blockchain. 
    // They represent the way you connect to the blockchain. 
    // With them you can only call view methods on contracts and get data from those contract.
    // Signers are authenticated providers conected to the current address in MetaMask.
    const signer = provider.getSigner();

    const factory = new ETHTickets__factory(signer);
    const nftTickets = factory.attach(config.contractAddress);

    nftTickets
      .mintNFT({
        from: wallet!,
        value: priceHexValue,
      })
      .then(async (tx: any) => {
        console.log('minting accepted')
        await tx.wait(1);
        console.log(`Minting complete, mined: ${tx}`);
        setIsMinting(false);
        router.reload()
      })
      .catch((error: any) => {
        console.log(error);
        setError(true);
        setErrorMessage(error?.message);
        setIsMinting(false);
      })
  };

We will discuss the function we just added in the workshop.

Finally, we will update the button inside the TicketsType component's JSX and add a call to the mintTicket() function:

        <Button disabled={isMinting} onClick={mintTicket}>

Our mintTicket() function has a few strategically placed console.log() statements so that we can tell if our minting button is working. At this point, if we are connected to the dApp with a MetaMask wallet that has some ETH in it, we can test those buttons out. Ensure you have your developer tools in your browser open to the console so we can see those logs once we mint. (comment out the router.reload() statement to ensure we can see the console messages and uncomment once we are sure it is working).

We should see:

minting accepted
Tickets.tsx?cd6d:55 Minting complete, mined: 0x......

With the minting now working we are ready to make our last set of changes to display the connected wallet's minted NFTs.

Add TicketsOwned Component to Minting Page

First we need to add the styles we will need to display our minted NFTs in a grid at the bottom of the page. Create a new file in the apps/web/components/styledComponents directory named ticketsOwned.js and add the following code:

import styled from "styled-components";

export const Grid = styled.div`
  display: grid;
  grid-template-columns: repeat(${props => props.columns || 2}, ${props => props.columnWidth}px);
  grid-template-rows: repeat(${props => props.itemWidth || "300"}px);
`;

export const SvgItem = styled.div`
  width: 300px;
  padding: ${props => props.pad || 0}px;
`;

In the apps/web/pages/index.tsx file we need to add one final component named <TicketsOwned />.

Create a file named TicketsOwned.tsx inside the apps/web/components directory. Since we have already reviewed code that gets our signer, provider, wallet state, etc. and since we have to repeat some of that same code on this page, we are just going to add all the code needed to display our minted NFT ticket SVGs in one shot and then talk about everything we have added.

In TicketsOwned.tsx, add the following code:

import { useState, useEffect } from "react";
import { ethers } from "ethers";
import Image from "next/image";

import { ETHTickets__factory } from "blockchain";
import { config } from "../../lib/config";
import { useMetaMask } from "../../hooks/useMetaMask";

import { Grid, SvgItem } from "../styledComponents/ticketsOwned";

type NftData = {
  name: string,
  description: string,
  attributes: { trait_type: any, value: any }[],
  owner: string,
  image: string
};

type TicketFormated = {
  tokenId: string
  svgImage: string
  ticketType:
  { trait_type: any, value: any }
};

const TicketsOwned = () => {
  const [ticketCollection, setTicketCollection] = useState<TicketFormated[]>([]);
  const { state: { wallet: address }, } = useMetaMask();

  useEffect(() => {
    if (typeof window !== "undefined" && address !== null) {
      const provider = new ethers.providers.Web3Provider(window.ethereum);
      const signer = provider.getSigner();

      const factory = new ETHTickets__factory(signer);
      const nftTickets = factory.attach(config.contractAddress);

      const ticketsRetrieved: TicketFormated[] = [];

      nftTickets.walletOfOwner(address).then((ownedTickets) => {
        const promises = ownedTickets.map(async (t) => {
          const currentTokenId = t.toString();
          const currentTicket = await nftTickets.tokenURI(currentTokenId);

          const base64ToString = window.atob(
            currentTicket.replace("data:application/json;base64,", "")
          );
          const nftData: NftData = JSON.parse(base64ToString);

          ticketsRetrieved.push({
            tokenId: currentTokenId,
            svgImage: nftData.image,
            ticketType: nftData.attributes.find(
              (t) => t.trait_type === "Ticket Type"
            ),
          } as TicketFormated);
        });
        Promise.all(promises).then(() => setTicketCollection(ticketsRetrieved));
      });
    }
  }, [address]);

  let listOfTickets = ticketCollection.map((ticket) => (
    <SvgItem pad={4} key={`ticket${ticket.tokenId}`}>
      <Image
        width={300}
        height={300}
        src={ticket.svgImage}
        alt={`Ticket# ${ticket.tokenId}`}
      />
    </SvgItem>
  ));

  return (
    <>
      <hr />
      <Grid columns={3} itemWidth={300} columnWidth={308}>{listOfTickets}</Grid>
    </>
  );
};

export default TicketsOwned;

At this point, each time you mint a new ticket, you should see them displayed as SVG at the bottom of the screen in a grid format. These are the exact NFTs your users will be minting and we are getting the SVG images directly from the deployed smart contract using the generateNftSvgByTokenId() method in our contract which takes a tokenId and builds the SVG just like the version it saves onchain to the ethereum blockchain.

This concludes the instructional portion of the workshop, we would love you to continue working on this project and adding your own features, iterating on the UI, adding better error handling, create tests and even deploy to a testnet. The MetaMask DevRel team can be contaced on Twitter Eric Bishard at @httpJunkie and Guillaume Bibeau at @GuiBibeau if you have questions or comments regarding the code or workshop!

Источник: dev.to

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