Intermediate

How to send token using ether.js

In This Tutorial You’ll Learn How To

• Import ethers.js

• Transfer token

• Set gas price according to the network traffic situation

To-Get-Started

To get started, we must first import the ethers.js library into our javascript Include ethers.js(5.0)

Installing

/home/ricmoo> npm install --save ethers

ES6 in the Browser

<script type="module">
  import { ethers } from "https://cdn.ethers.io/lib/ethers-5.0.esm.min.js"
  // Your code here...
</script>

ES3(UMD) in the Browser

<script
  src="https://cdn.ethers.io/lib/ethers-5.0.umd.min.js"
  type="application/javascript"
></script>

Parameters

1. contract_address: Token contract address (contract address is needed when the token you want to transfer is not ether)

2. send_token_amount: The amount you want to send to the receiver

3. to_address: The receiver’s address

4. send_account: The sender’s address

5. private_key: Private key of the sender to sign the transaction and actually transfer the tokens

NOTICE

signTransaction(tx) is removed because sendTransaction() does it internally.

SENDING PROCEDURES

1. Connect to network (testnet)

Set Provider (Infura)

Connect to Ropsten testnet

window.ethersProvider = new ethers.providers.InfuraProvider("ropsten")

2. Create wallet

let wallet = new ethers.Wallet(private_key)

3. Connect Wallet to net

let walletSigner = wallet.connect(window.ethersProvider)2

4. Get current gas price

window.ethersProvider.getGasPrice() // gasPrice2

const tx = {
  from: send_account,
  to: to_address,
  value: ethers.utils.parseEther(send_token_amount),
  nonce: window.ethersProvider.getTransactionCount(send_account, "latest"),
  gasLimit: ethers.utils.hexlify(gas_limit), // 100000
  gasPrice: gas_price,
}

walletSigner.sendTransaction(tx).then((transaction) => {
  console.dir(transaction)
  alert("Send finished!")
})

HOW TO USE IT

let private_key =
  "41559d28e936dc92104ff30691519693fc753ffbee6251a611b9aa1878f12a4d"
let send_token_amount = "1"
let to_address = "0x4c10D2734Fb76D3236E522509181CC3Ba8DE0e80"
let send_address = "0xda27a282B5B6c5229699891CfA6b900A716539E6"
let gas_limit = "0x100000"
let wallet = new ethers.Wallet(private_key)
let walletSigner = wallet.connect(window.ethersProvider)
let contract_address = ""
window.ethersProvider = new ethers.providers.InfuraProvider("ropsten")

send_token(
  contract_address,
  send_token_amount,
  to_address,
  send_address,
  private_key
)

Success!

SEND_TOKEN()

function send_token(
  contract_address,
  send_token_amount,
  to_address,
  send_account,
  private_key
) {
  let wallet = new ethers.Wallet(private_key)
  let walletSigner = wallet.connect(window.ethersProvider)

  window.ethersProvider.getGasPrice().then((currentGasPrice) => {
    let gas_price = ethers.utils.hexlify(parseInt(currentGasPrice))
    console.log(`gas_price: ${gas_price}`)

    if (contract_address) {
      // general token send
      let contract = new ethers.Contract(
        contract_address,
        send_abi,
        walletSigner
      )

      // How many tokens?
      let numberOfTokens = ethers.utils.parseUnits(send_token_amount, 18)
      console.log(`numberOfTokens: ${numberOfTokens}`)

      // Send tokens
      contract.transfer(to_address, numberOfTokens).then((transferResult) => {
        console.dir(transferResult)
        alert("sent token")
      })
    } // ether send
    else {
      const tx = {
        from: send_account,
        to: to_address,
        value: ethers.utils.parseEther(send_token_amount),
        nonce: window.ethersProvider.getTransactionCount(
          send_account,
          "latest"
        ),
        gasLimit: ethers.utils.hexlify(gas_limit), // 100000
        gasPrice: gas_price,
      }
      console.dir(tx)
      try {
        walletSigner.sendTransaction(tx).then((transaction) => {
          console.dir(transaction)
          alert("Send finished!")
        })
      } catch (error) {
        alert("failed to send!!")
      }
    }
  })
}