contract-ts

Donation Contract

The smart contract exposes methods to handle donating $NEAR to a beneficiary.

@call
donate() {
  // Get who is calling the method and how much $NEAR they attached
  let donor = near.predecessorAccountId(); 
  let donationAmount: bigint = near.attachedDeposit() as bigint;

  let donatedSoFar = this.donations.get(donor) === null? BigInt(0) : BigInt(this.donations.get(donor) as string)
  let toTransfer = donationAmount;

  // This is the user's first donation, lets register it, which increases storage
  if(donatedSoFar == BigInt(0)) {
    assert(donationAmount > STORAGE_COST, `Attach at least ${STORAGE_COST} yoctoNEAR`);

    // Subtract the storage cost to the amount to transfer
    toTransfer -= STORAGE_COST
  }

  // Persist in storage the amount donated so far
  donatedSoFar += donationAmount
  this.donations.set(donor, donatedSoFar.toString())

  // Send the money to the beneficiary
  const promise = near.promiseBatchCreate(this.beneficiary)
  near.promiseBatchActionTransfer(promise, toTransfer)

  // Return the total amount donated so far
  return donatedSoFar.toString()
}

Quickstart

1. Make sure you have installed node.js >= 16.
2. Install the NEAR CLI

1. Build and Deploy the Contract

You can automatically compile and deploy the contract in the NEAR testnet by running:

npm run deploy

Once finished, check the neardev/dev-account file to find the address in which the contract was deployed:

cat ./neardev/dev-account
# e.g. dev-1659899566943-21539992274727

The contract will be automatically initialized with a default beneficiary.

To initialize the contract yourself do:

# Use near-cli to initialize contract (optional)
near call <dev-account> init '{"beneficiary":"<account>"}' --accountId <dev-account>

2. Get Beneficiary

beneficiary is a read-only method (view method) that returns the beneficiary of the donations.

View methods can be called for free by anyone, even people without a NEAR account!

near view <dev-account> beneficiary

3. Get Number of Donations

donate forwards any attached money to the beneficiary while keeping track of it.

donate is a payable method for which can only be invoked using a NEAR account. The account needs to attach money and pay GAS for the transaction.

# Use near-cli to donate 1 NEAR
near call <dev-account> donate --amount 1 --accountId <account>

Tip: If you would like to donate using your own account, first login into NEAR using:

# Use near-cli to login your NEAR account
near login

and then use the logged account to sign the transaction: --accountId <your-account>.