Created
November 14, 2022 01:19
-
-
Save nhancv/bf3e07e272824d5802ec4dc5909e2ce6 to your computer and use it in GitHub Desktop.
Example web3 - Metamask
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
| <!-- Localhost start: http-server --> | |
| <html> | |
| <link | |
| rel="icon" | |
| type="image/x-icon" | |
| href="https://www.mozilla.org/media/img/favicons/firefox/browser/favicon.f093404c0135.ico" | |
| /> | |
| <script src="https://cdn.jsdelivr.net/npm/web3@latest/dist/web3.min.js"></script> | |
| <script> | |
| const setupWeb3 = async () => { | |
| // Switch to BSC Testnet | |
| const web3 = new Web3(window.ethereum); | |
| // Request switch to Binance Smart Chain Testnet | |
| try { | |
| // check if the chain to connect to is installed | |
| await window.ethereum.request({ | |
| method: "wallet_switchEthereumChain", | |
| params: [{ chainId: "0x61" }], // chainId must be in hexadecimal numbers | |
| }); | |
| } catch (error) { | |
| // This error code indicates that the chain has not been added to MetaMask | |
| // if it is not, then install it into the user MetaMask | |
| if (error.code === 4902) { | |
| try { | |
| await window.ethereum.request({ | |
| method: "wallet_addEthereumChain", | |
| params: [ | |
| { | |
| chainId: "0x61", | |
| rpcUrl: "https://data-seed-prebsc-1-s1.binance.org:8545/", | |
| }, | |
| ], | |
| }); | |
| } catch (addError) { | |
| console.error(addError); | |
| } | |
| } | |
| console.error(error); | |
| } | |
| // Create Presenter Contract Instance | |
| const contractAddress = "0x0dE8FCAE8421fc79B29adE9ffF97854a424Cad09"; | |
| const contractAbi = | |
| '[{"anonymous":false,"inputs":[{"indexed":true,"internalType":"address","name":"owner","type":"address"},{"indexed":true,"internalType":"address","name":"spender","type":"address"},{"indexed":false,"internalType":"uint256","name":"value","type":"uint256"}],"name":"Approval","type":"event"},{"anonymous":false,"inputs":[{"indexed":true,"internalType":"address","name":"from","type":"address"},{"indexed":true,"internalType":"address","name":"to","type":"address"},{"indexed":false,"internalType":"uint256","name":"value","type":"uint256"}],"name":"Transfer","type":"event"},{"inputs":[],"name":"name","outputs":[{"internalType":"string","name":"","type":"string"}],"stateMutability":"view","type":"function"},{"inputs":[],"name":"symbol","outputs":[{"internalType":"string","name":"","type":"string"}],"stateMutability":"view","type":"function"},{"inputs":[],"name":"decimals","outputs":[{"internalType":"uint8","name":"","type":"uint8"}],"stateMutability":"view","type":"function"},{"inputs":[],"name":"totalSupply","outputs":[{"internalType":"uint256","name":"","type":"uint256"}],"stateMutability":"view","type":"function"},{"inputs":[{"internalType":"address","name":"account","type":"address"}],"name":"balanceOf","outputs":[{"internalType":"uint256","name":"","type":"uint256"}],"stateMutability":"view","type":"function"},{"inputs":[{"internalType":"address","name":"recipient","type":"address"},{"internalType":"uint256","name":"amount","type":"uint256"}],"name":"transfer","outputs":[{"internalType":"bool","name":"","type":"bool"}],"stateMutability":"nonpayable","type":"function"},{"inputs":[{"internalType":"address","name":"owner","type":"address"},{"internalType":"address","name":"spender","type":"address"}],"name":"allowance","outputs":[{"internalType":"uint256","name":"","type":"uint256"}],"stateMutability":"view","type":"function"},{"inputs":[{"internalType":"address","name":"spender","type":"address"},{"internalType":"uint256","name":"amount","type":"uint256"}],"name":"approve","outputs":[{"internalType":"bool","name":"","type":"bool"}],"stateMutability":"nonpayable","type":"function"},{"inputs":[{"internalType":"address","name":"sender","type":"address"},{"internalType":"address","name":"recipient","type":"address"},{"internalType":"uint256","name":"amount","type":"uint256"}],"name":"transferFrom","outputs":[{"internalType":"bool","name":"","type":"bool"}],"stateMutability":"nonpayable","type":"function"},{"inputs":[{"internalType":"address","name":"spender","type":"address"},{"internalType":"uint256","name":"addedValue","type":"uint256"}],"name":"increaseAllowance","outputs":[{"internalType":"bool","name":"","type":"bool"}],"stateMutability":"nonpayable","type":"function"},{"inputs":[{"internalType":"address","name":"spender","type":"address"},{"internalType":"uint256","name":"subtractedValue","type":"uint256"}],"name":"decreaseAllowance","outputs":[{"internalType":"bool","name":"","type":"bool"}],"stateMutability":"nonpayable","type":"function"}]'; | |
| const instanceContract = new web3.eth.Contract( | |
| JSON.parse(contractAbi), | |
| contractAddress | |
| ); | |
| // Extract data | |
| const mockUser = "0x0000000000000000000000000000000000000000"; | |
| const balanceInfo = await instanceContract.methods | |
| .balanceOf(mockUser) | |
| .call(); | |
| console.log({ balanceInfo: web3.utils.fromWei(balanceInfo) }); | |
| }; | |
| setupWeb3(); | |
| </script> | |
| </html> |
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment