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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​


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npm install @onflow/fcl
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npm install flow-catalog

or


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yarn add @onflow/fcl
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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.


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import { getAddressMaps, scripts } from "flow-catalog";
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import * as fcl from "@onflow/fcl"
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const main = async () => {
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const addressMap = await getAddressMaps();
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console.log(await scripts.getSupportedGeneratedTransactions(addressMap));
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};
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main();

2. Provide a Catalog collection identifier to generate code


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const getTemplatedTransactionCode = async function() {
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const catalogAddressMap = await getAddressMaps()
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const result = await cadence.scripts.genTx({
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/*
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'CollectionInitialization' is one of the available transactions from step 1.
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'Flunks' is the collection identifier in this case
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'Flow' is a fungible token identifier (if applicable to the transaction being used)
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*/
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args: ['CollectionInitialization', 'Flunks', 'flow'],
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addressMap: catalogAddressMap
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})
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return result
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}

3. Use the generated code in a transaction


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const txId = await fcl.mutate({
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cadence: await getTemplatedTransactionCode()[0],
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limit: 9999,
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args: (arg: any, t: any) => []
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});
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const transaction = await fcl.tx(txId).onceSealed()
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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.