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Conventional auction sale contract

This section provides reference information for writing a smart contract to conduct a conventional auction using Marmalade on the Kadena network. The reference information includes the capabilities, schemas, tables, functions, and constants defined for a conventional auction.

Source code: conventional-auction.pact

Capabilities

The conventional auction smart contract defines the following capabilities to manage permissions:

  • GOVERNANCE: Defines governance for the contract and is controlled by the keyset defined under the ADMIN-KS constant.
  • AUCTION_CREATED: Specifies the event emitted when the create-auction function is executed. The emitted event includes the sale-id, token-id, and escrow fields.
  • MANAGE_AUCTION: Identifies a guard to control who can create and update an auction. You must specify the sale-id and token-id parameters when you use this capability in create-auction and update-auction functions.
  • BID_PLACED: Specifies the event emitted when a bid is place. The emitted event includes the bidder?, bid-amount, and timestamp fields.
  • PLACE_BID: Ensures that the bidder signs the transaction to place the bid.
  • REFUND_CAP: Protects funds held in escrow to ensure refunds can be made, if necessary.

Schemas

The conventional auction smart contract defines two schemas.

The auctions-schema describes the following information for a conventional auction:

  • token-id
  • start-date
  • end-date
  • highest-bid
  • highest-bid-id
  • reserve-price

The bids-schema describes the following information for a conventional auction:

  • bidder
  • bidder-guard
  • bid

Tables

The conventional auction contract stores auction information in the auctions table and bid information in the bids table.

Functions

The conventional auction contract defines the following functions to manage token sales using the conventional auction format:

  • escrow-account: Returns the auction's fungible escrow account name.
  • escrow-guard: Returns the account guard of the escrow account.
  • enforce-fungible-transfer: Requires that policy-manager.FUNGIBLE_TRANSFER_CALL capability is in scope.
  • enforce-quote-update: Enforces a quote update when required for sale contracts. This function is called by the policy-manager.enforce-buy function to validate that only the winning bidder processes the marmalade.buy call, the escrow payment, and the marketplace fee.
  • enforce-withdrawal: Enforces a withdrawal when required for sale contracts. This function is called by the policy-manager.enforce-withdraw function to validate that the auction has expired, or that the bid has already been placed.
  • create-bid-id: Generates a unique bid identifier by hashing the sale-id, bidder, and block-time fields.
  • create-auction: Allows sellers to create a conventional auction for their token after providing auction information.
  • update-auction: Allows sellers to update auction information before the auction start time.
  • retrieve-auction: Retrieves auction information from the auctions table.
  • retrieve-bid: Retrieves bid information from the bids table.
  • place-bid: Transfers the bid amount in a fungible currency from the bidder account to an escrow account and records the bids in the blockchain.

Constants

The conventional auction contract defines the following constant:

  • ADMIN-KS: Sets the marmalade-sale.marmalade-contract-admin for the GOVERNANCE capability.