import FungibleToken from 0xf233dcee88fe0abe import NonFungibleToken from 0x1d7e57aa55817448 import NFTStorefront from 0x4eb8a10cb9f87357 import PackNFT, AllDay from 0xe4cf4bdc1751c65d import DapperUtilityCoin from 0xead892083b3e2c6c transaction( storefrontAddress: Address, listingResourceID: UInt64, expectedPrice: UFix64 ) { let paymentVault: @FungibleToken.Vault let buyerNFTCollection: &AnyResource{NonFungibleToken.CollectionPublic} let storefront: &NFTStorefront.Storefront{NFTStorefront.StorefrontPublic} let listing: &NFTStorefront.Listing{NFTStorefront.ListingPublic} let balanceBeforeTransfer: UFix64 let mainDUCVault: &DapperUtilityCoin.Vault let nflAddress: Address prepare(nfl: AuthAccount, dapper: AuthAccount, buyer: AuthAccount) { self.nflAddress = nfl.address // Initialize the AllDay collection if the buyer does not already have one if buyer.borrow<&AllDay.Collection>(from: AllDay.CollectionStoragePath) == nil { // save it to the account buyer.save(<-AllDay.createEmptyCollection(), to: AllDay.CollectionStoragePath) // create a public capability for the collection buyer.link<&AllDay.Collection{NonFungibleToken.CollectionPublic, AllDay.MomentNFTCollectionPublic}>( AllDay.CollectionPublicPath, target: AllDay.CollectionStoragePath ) ?? panic("Could not link AllDay.Collection Pub Path"); } // Initialize the PackNFT collection if the buyer does not already have one if buyer.borrow<&PackNFT.Collection>(from: PackNFT.CollectionStoragePath) == nil { buyer.save(<-PackNFT.createEmptyCollection(), to: PackNFT.CollectionStoragePath); buyer.link<&{NonFungibleToken.CollectionPublic}>(PackNFT.CollectionPublicPath, target: PackNFT.CollectionStoragePath) ?? panic("Could not link PackNFT.Collection Pub Path"); } // Although the Storefront is available as a public capability, we want to borrow // from storage so that we can enforce the need for PackNFT to sign this transaction self.storefront = nfl .getCapability<&NFTStorefront.Storefront{NFTStorefront.StorefrontPublic}>(NFTStorefront.StorefrontPublicPath) .borrow() ?? panic("Could not borrow a reference to the storefront") self.listing = self.storefront.borrowListing(listingResourceID: listingResourceID) ?? panic("No Listing with that ID in Storefront") let salePrice = self.listing.getDetails().salePrice if expectedPrice != salePrice { panic("Sale price not expected value") } self.mainDUCVault = dapper.borrow<&DapperUtilityCoin.Vault>(from: /storage/dapperUtilityCoinVault) ?? panic("Could not borrow reference to Dapper Utility Coin vault") self.balanceBeforeTransfer = self.mainDUCVault.balance self.paymentVault <- self.mainDUCVault.withdraw(amount: salePrice) self.buyerNFTCollection = buyer .getCapability<&{NonFungibleToken.CollectionPublic}>(PackNFT.CollectionPublicPath) .borrow() ?? panic("Cannot borrow NFT collection receiver from account") } pre { self.nflAddress == 0xe4cf4bdc1751c65d && self.nflAddress == storefrontAddress: "Requires valid authorizing signature" } execute { let item <- self.listing.purchase( payment: <-self.paymentVault ) self.buyerNFTCollection.deposit(token: <-item) } post { self.mainDUCVault.balance == self.balanceBeforeTransfer: "DUC leakage" } }

CODE_ERROR

Transaction