Flow Cadence Utilities API Reference

Imports

extractImports(code)

Arguments

Name	Type	Description
code	string	Cadence template code

Returns

Type	Description
object	contract name as key and import address as value

Usage

_20

import { extractImports } from '@onflow/flow-cadut';

_20

_20

const code = `

_20

import Message from 0x01

_20

import Utilities from 0x02

_20

_20

pub fun main(){

_20

Utilities.log(Message.hello)

_20

}

_20

`;

_20

const imports = extractImports(code);

_20

_20

console.log(imports);

_20

/*

_20

* Line above shall show the following:

_20

* {

_20

* "Message": "0x01",

_20

* "Utilities": "0x02"

_20

* }

_20

* */

missingImports(code, addressMap)

Given Cadence code template and addressMap, returns an array of missing contract imports

Arguments

Name	Type	Description
code	string	Cadence template code
addressMap	AddressMap	addressMap for provided template

Returns

Type	Description
array	array strings, representing names of missing contract imports

Usage

_13

import { missingImports } from '@onflow/flow-cadut';

_13

_13

const code = `

_13

import Message from 0x01

_13

import Utilities from 0x02

_13

_13

pub fun main(){

_13

Utilities.log(Message.hello)

_13

}

_13

`;

_13

_13

const missing = missingImports(code, {});

_13

console.log({ missing });

report(list, prefix)

Reports missing imports via console.error with format:

_10

[prefix] Missing Imports for contracts: [ Contract_1, Contract_2 ]

Arguments

Name	Type	Optional	Description
list	array		list of missing contract imports
prefix	string	✅	Default: ""

Usage

_10

import { missingImports, report } from '@onflow/flow-cadut';

_10

const code = `

_10

import Message from 0x01

_10

_10

pub fun main(){}

_10

`;

_10

const list = missingImports(code, {});

_10

report(list);

reportMissingImports(code, addressMap, prefix)

Checks and reports missing contracts by matching code and addressMap in format:

_10

[prefix] Missing Imports for contracts: [ Contract_1, Contract_2 ]

Arguments

Name	Type	Optional	Description
code	string		Cadence template code to check
addressMap	AddressMap	✅	addressMap for imported contracts. Default: {}
prefix	string	✅	message prefix. Default: ""

Usage

_10

import { missingImports, report } from '@onflow/flow-cadut';

_10

_10

const code = `

_10

import Message from 0x01

_10

_10

pub fun main(){}

_10

`;

_10

_10

reportMissingImports(code);

replaceImportAddresses(code, addressMap)

Replaces import statements in provided Cadence templates with corresponding values from addressMap

Arguments

Name	Type	Description
code	string	Cadence template code
addressMap	AddressMap	AddressMap to use map contract names to addresses

Returns

Type	Description
string	Updated template with replaced addresses

Usage

_12

import { replaceImportAddresses } from '@onflow/flow-cadut';

_12

_12

const code = `

_12

import Messages from 0x01

_12

_12

pub fun main(){}

_12

`;

_12

const addressMap = {

_12

Message: '0xf8d6e0586b0a20c7',

_12

};

_12

const replaced = replaceImportAddresses(code, addressMap);

_12

console.log({ replaced });

Arguments

mapArgument(type, value)

Converts provided value to sdk argument.

📣 Best usage of this method is with combination of query/mutate methods from Javascript SDK.

Arguments

Name	Type	Description
type	string	Cadence type represented as string
value	any	correspondent value to use for conversion

Returns

Type	Description
Argument	sdk argument

Usage

_22

import { query, config } from '@onflow/fcl';

_22

import { mapArgument } from '@onflow/flow-cadut';

_22

_22

(async () => {

_22

config().put('accessNode.api', 'https://rest-testnet.onflow.org');

_22

_22

const cadence = `

_22

pub fun main(message: String): String{

_22

return message

_22

}

_22

`;

_22

_22

// Script expects a single argument of type "String"

_22

const message = mapArgument('String', 'Hello from Cadence!');

_22

_22

// "args" shall return array of arguments.

_22

// We will pass "message" value into it

_22

const args = () => [message];

_22

_22

const result = await query({ cadence, args });

_22

console.log(result);

_22

})();

mapArguments(schema, values)

Converts provided values to sdk arguments.

📣 Best usage of this method is with combination of query/mutate methods from Javascript SDK.

Arguments

Name	Type	Description
schema	array[string]	Array of Cadence types represented as string
values	array[any]	array of correspondent values to use for conversion

Returns

Type	Description
array[Argument]	array of sdk arguments

Usage

_23

import { query, config } from '@onflow/fcl';

_23

import { mapArgument } from '@onflow/flow-cadut';

_23

_23

(async () => {

_23

config().put('accessNode.api', 'https://rest-testnet.onflow.org');

_23

_23

const cadence = `

_23

pub fun main(message: String, amount: Int): Int{

_23

log(message)

_23

return amount

_23

}

_23

`;

_23

_23

// Script expects multiple arguments - "String" and "Int"

_23

const schema = ['String', 'Int'];

_23

// These are the values we will convert to arguments

_23

const values = ['Hello from Cadence', 1337];

_23

// mapArguments will return an array, no extra steps are required

_23

const args = () => mapArguments(schema, values);

_23

_23

const result = await query({ cadence, args });

_23

console.log(result);

_23

})();

mapValuesToCode(code, values)

This method will extract argument types from provided Cadence code and then converts values to corresponding types, preparing them to be passed into sdk.send

📣 Best usage of this method is with combination of query/mutate methods from Javascript SDK.

Arguments

Name	Type	Description
code	string	Cadence template code
values	array	array of values to process

Returns

Type	Description
array	array of sdk arguments

Throws

This method will throw an error if user would fail to provide required amount of arguments

_23

import { query, config } from '@onflow/fcl';

_23

import { mapValuesToCode } from '@onflow/flow-cadut';

_23

_23

(async () => {

_23

config().put('accessNode.api', 'https://rest-testnet.onflow.org');

_23

_23

const cadence = `

_23

pub fun main(metadata: {String:String}, key: String):String {

_23

return metadata[key]!

_23

}

_23

`;

_23

_23

const result = await query({

_23

cadence,

_23

args: () =>

_23

mapValuesToCode(cadence, [

_23

{ language: 'Cadence', languageRating: 'Cadence is Awesome 🤟' },

_23

'languageRating',

_23

]),

_23

});

_23

_23

console.log(result);

_23

})();

Parser

getTemplateInfo(code)

Parses the code and returns TemplateInfo

Arguments

Name	Type	Description
code	string	Cadence template code to process

Usage

_17

import { getTemplateInfo } from '@onflow/flow-cadut';

_17

_17

const script = `

_17

pub fun main(message:String):String{

_17

return 42

_17

}

_17

`;

_17

const info = getTemplateInfo(script);

_17

_17

/*

_17

* "info" will contain an object:

_17

* {

_17

* type: "script",

_17

* args: [ 'message:String' ]

_17

* }

_17

*/

_17

console.log({ info });

extractSigners(code)

Parses the code and returns array of SignerPair

Arguments

Name	Type	Description
code	string	Cadence template code to process

Returns

Type	Description
SignerPair	String representation of signer pair

Usage

_10

import { extractSigners } from '@onflow/flow-cadut';

_10

_10

const script = `

_10

pub fun main(){

_10

log("nothing to see here :)")

_10

}

_10

`;

_10

const signers = extractSigners(script);

_10

console.log({ signers });

extractScriptArguments(code)

Parses the code and returns array of ArgumentPair

Arguments

Name	Type	Description
code	string	Cadence template code to process

Returns

Type	Description
ArgumentPair	String representation of argument pair

Usage

_10

import { extractScriptArguments } from '@onflow/flow-cadut';

_10

_10

const script = `

_10

pub fun main(message: String, metadata: {String:String}){

_10

log(message)

_10

}

_10

`;

_10

const args = extractScriptArguments(script);

_10

console.log({ args });

extractTransactionArguments(code)

Parses the code and returns array of ArgumentPair

Arguments

Name	Type	Description
code	string	Cadence template code to process

Returns

Type	Description
ArgumentPair	String representation of argument pair

Usage

_11

import { extractTransactionArguments } from '@onflow/flow-cadut';

_11

_11

const tx = `

_11

transaction(message: String, metadata: {String:String}){

_11

prepare(signer:AuthAccount){

_11

_11

}

_11

}

_11

`;

_11

const args = extractTransactionArguments(tx);

_11

console.log({ args });

extractContractName(code)

Parses the code and returns contract name

Arguments

Name	Type	Description
code	string	Cadence template code to process

Returns

Type	Description
string	name of the contract defined in template code

Usage

_10

import { extractContractName } from '@onflow/flow-cadut';

_10

_10

const contract = `

_10

pub contract HelloWorld{

_10

init(){}

_10

}

_10

`;

_10

const name = extractContractName(contract);

_10

console.log({ name });

splitArgs(pair)

Splits ArgumentPair into array of two items

Arguments

Name	Type	Description
pair	ArgumentPair	argument pair in form of a string

Returns

Type	Description
array	first item is a name, second - string representation of type

Usage

_10

import { splitArgs } from '@onflow/flow-cadut';

_10

const simplePair = 'message:String';

_10

const metaPair = 'metadata: {String:String}';

_10

_10

const simple = splitArgs(simplePair);

_10

const meta = splitArgs(metaPair);

_10

_10

console.log({ simple, meta });

argType(pair)

Splits ArgumentPair and returns type of the argument

Arguments

Name	Type	Description
`pair	ArgumentPair	argument pair in form of a string

Returns

Type	Description
string	string representation of argument type

Usage

_10

import { argType } from '@onflow/flow-cadut';

_10

_10

const simplePair = 'message:String';

_10

const metaPair = 'metadata: {String:String}';

_10

_10

const simple = argType(simplePair);

_10

const meta = argType(metaPair);

_10

_10

console.log({ simple, meta });

getArrayType(type)

Extracts item type from array type

Arguments

Name	Type	Description
type	string	string representation of Array type

Returns

Type	Description
string	string representation of item type

Usage

_10

import { getArrayType } from '@onflow/flow-cadut';

_10

_10

const simpleType = getArrayType('[String]');

_10

const complexType = getArrayType('[{String: String}]');

_10

_10

console.log({ simpleType, complexType });

getDictionaryTypes(type)

Extracts key and value types from Dictionary type

Arguments

Name	Type	Description
type	string	string representation of Dictionary type

Returns

Type	Description
array	array of strings - first item for the key type, second for the value type

Usage

_10

import { getDictionaryTypes } from '@onflow/flow-cadut';

_10

_10

const type = '{String: UFix64}';

_10

const types = getDictionaryTypes(type);

_10

const [keyType, valueType] = types;

_10

_10

console.log({ keyType, valueType });

Generator

processFolder(input, output, options)

Recursively goes through input folder and generates code for found contracts, transactions and scripts. Write files under output path.

Arguments

Name	Type	Optional	Description
input	string		path to the input folder
output	string		path to output folder
options	object	✅	additional options. Default: {}

Options

Name	Type	Optional	Description
dependency	string	✅	interactions dependency. Default: flow-cadut

Usage

_10

import path from 'path';

_10

import { processFolder } from '@onflow/flow-cadut';

_10

_10

(async () => {

_10

const input = path.resolve('./cadence');

_10

const output = path.resolve('./src/generated/localRegistry');

_10

_10

await processFolder(input, output);

_10

console.log('✅ Done!');

_10

})();

processGitRepo(url, output, branch, options)

Fetches GitHub repository from provided url and branch. Then generates code for found contracts, transactions and scripts. Write files under output path.

Arguments

Name	Type	Optional	Description
url	string		url to GitHub repo
output	string		path to output folder
branch	string	✅	branch to use. Default: main
options	object	✅	additional options. Default: {}

Options

Name	Type	Optional	Description
dependency	string	✅	interactions dependency. Default: flow-cadut

Usage

_10

import path from 'path';

_10

import { processGitRepo } from '@onflow/flow-cadut';

_10

_10

(async () => {

_10

const url = path.resolve('https://github.com/onflow/flow-core-contracts');

_10

const output = path.resolve('./src/generated/localRegistry');

_10

_10

await processGitRepo(url, output);

_10

console.log('✅ Done!');

_10

})();

Interactions

setEnvironment(network, options)

Sets flow.network config value

Arguments

Name	Type	Optional	Description
network	string	✅	network to use. Default: emulator
options	object	✅	extra options to adjust config

Network Variants

Variants	Description
emulator	Emulator instance running locally at http://localhost:8080
testnet	Testnet access node at https://access-testnet.onflow.org
mainnet	Mainnet access node at https://access.mainnet.onflow.org

Options

Name	Type	Optional	Description
options.port	number	✅	port for emulator. Default: 8080
options.endpoint	string	✅	Access API endpoint.

⚠️ Attention: endpoint will override port and provided network. Don't mix endpoint from different network - it might lead to unexpected result.

Usage

_10

import { setEnvironment } from '@onflow/flow-cadut';

_10

_10

(async () => {

_10

await setEnvironment('testnet');

_10

})();

getEnvironment()

Returns a set of deployed contracts for current environment

Returns

Type	Description
object	AddressMap for known contracts deployed in current environment

Usage

_10

import { setEnvironment, getEnvironment } from '@onflow/flow-cadut';

_10

_10

(async () => {

_10

await setEnvironment('mainnet');

_10

const addressMap = await getEnvironment();

_10

console.log({ addressMap });

_10

})();

hexContract(code)

Prepares Cadence template code to pass into deployment transaction. Syntax sugar for Buffer.from(code, "utf8").toString("hex");

Arguments

Name	Type	Description
code	string	Cadence template code

Returns

Type	Description
string	hex representation of template code

Usage

_10

import { hexContract } from '@onflow/flow-cadut';

_10

_10

const code = `

_10

pub contract HelloWorld{

_10

init(){}

_10

}

_10

`;

_10

const hexed = hexContract(code);

executeScript(args)

Sends script to the network

Arguments

Name	Type	Description
args	ScriptArguments	script arguments

Returns

Type	Description
ScriptResult	Result of script execution.

ScriptArguments

Name	Type	Optional	Description
code	string		Cadence code to execute
args	arrayInteractionArgument	✅	Optional if script does not expect arguments. Default: []
addressMap	AddressMap	✅	address map to use for import replacement. Default: {}
limit	number	✅	gas limit. Default: 100

ScriptResult

Script result is represented as a tuple [result, error]

Name	Type	Description
result	any	result of script execution. Type of this value depends on script return value
error	error	Caught error. This will be null if script executed successfully

Usage

_12

import { executeScript } from '@onflow/flow-cadut';

_12

_12

(async () => {

_12

const code = `

_12

pub fun main():Int{

_12

return 42

_12

}

_12

`;

_12

_12

const [result, err] = executeScript({ code });

_12

console.log({ result });

_12

})();

Alias

This method is also available under alias query

sendTransaction

Sends script to the network

Arguments

Name	Type	Optional	Description
args	TransactionArguments		transaction arguments
waitForExecution	boolean	✅	wait for transaction execution or not

If waitForExecution flag is set to true, method will not return result until fcl.tx(hash).onceExecuted() is resolved

Returns

Type	Description
TransactionResult	Result of script execution.

TransactionArguments

Name	Type	Optional	Description
code	string		Cadence code to execute
payer	AuthorizationFunction		The authorization function that returns a valid AuthorizationObject for the payer role.
signers	[AuthorizationFunction]	✅	an array of AuthorizationObject representing transaction authorizers. Default: same as payer
proposer	AuthorizationFunction	✅	The authorization function that returns a valid AuthorizationObject for the proposer role. Default: same as payer
args	[Any]	✅	Optional if transactions does not expect arguments. Default: []
addressMap	AddressMap	✅	address map to use for import replacement. Default: {}
limit	number	✅	gas limit. Default: 100

When being used in the browser, you can pass built-in fcl.authz function to produce the authorization (signatures) for the current user. When calling this method from Node.js, you will need to supply your own custom authorization functions.

TransactionResult

Transaction result is represented as a tuple [result, error]

Name	Type	Description
ResponseObject	any	result of transaction execution. Type of this value depends on script return value
error	error	Caught error. This will be null if script executed successfully

Usage

_23

import { authenticate, currentUser, authz, config } from '@onflow/fcl';

_23

import { sendTransaction } from '@onflow/flow-cadut';

_23

_23

config()

_23

.put('accessNode.api', 'https://rest-testnet.onflow.org') // Configure FCL's Access Node

_23

.put('challenge.handshake', 'https://fcl-discovery.onflow.org/testnet/authn') // Configure FCL's Wallet Discovery mechanism

_23

.put('0xProfile', '0xba1132bc08f82fe2'); // Will let us use `0xProfile` in our Cadence

_23

_23

(async () => {

_23

currentUser().subscribe(async (user) => {

_23

const code = `

_23

transaction {

_23

prepare(currentUser: AuthAccount) {

_23

log("hello")

_23

}

_23

}`;

_23

_23

const [result] = await sendTransaction({ code, payer: authz });

_23

console.log({ result });

_23

});

_23

_23

authenticate();

_23

})();

Alias

This method is also available under alias mutate