Cadence Generation

Using the NFT Catalog, you can generate common scripts and transactions to be run against the Flow Blockchain to support your application.

How-to generate scripts and transactions

From JavaScript

Installation

npm install @onflow/fcl

npm install flow-catalog

or

yarn add @onflow/fcl

yarn add flow-catalog

Usage

1. Retrieve a list of transactions available for code generation: NOTE: In order to properly bootstrap the method, you will need to run and await on the getAddressMaps() method, passing it into all of the methods as shown below.

import { getAddressMaps, scripts } from "flow-catalog";

import * as fcl from "@onflow/fcl"

const main = async () => {

const addressMap = await getAddressMaps();

console.log(await scripts.getSupportedGeneratedTransactions(addressMap));

};

main();

2. Provide a Catalog collection identifier to generate code

const getTemplatedTransactionCode = async function() {

const catalogAddressMap = await getAddressMaps()

const result = await cadence.scripts.genTx({

/*

'CollectionInitialization' is one of the available transactions from step 1.

'Flunks' is the collection identifier in this case

'Flow' is a fungible token identifier (if applicable to the transaction being used)

*/

args: ['CollectionInitialization', 'Flunks', 'flow'],

addressMap: catalogAddressMap

})

return result

}

3. Use the generated code in a transaction

const txId = await fcl.mutate({

cadence: await getTemplatedTransactionCode()[0],

limit: 9999,

args: (arg: any, t: any) => []

});

const transaction = await fcl.tx(txId).onceSealed()

return transaction

From non-javascript environments

Cadence scripts and transactions can be generated directly on-chain via scripts. You will need to be able to run cadence scripts to continue.

1. Retrieve a list of transactions available for code generation

Run the following script to retrieve available code generation methods: https://github.com/dapperlabs/nft-catalog/blob/main/cadence/scripts/get_supported_generated_transactions.cdc

2. Provide a catalog collection identifier to generate code

You may use the following script to generate code: https://github.com/dapperlabs/nft-catalog/blob/main/cadence/scripts/gen_tx.cdc

For example, from the CLI this may be run like the following: flow -n mainnet scripts execute ./get_tx.cdc CollectionInitialization Flunks flow

In the above example, CollectionInitialization is one of the supported transactions returned from step 1, Flunks is the name of an entry on the catalog (https://www.flow-nft-catalog.com/catalog/mainnet/Flunks), and flow is a fungible token identifier.