Swift SDK
ICON supports SDK for 3rd party or user services development. You can integrate ICON SDK for your project and utilize the ICONās functionality. This document provides you with information about API specification.
class ICONService
ICONService is a class which provides APIs to communicate with ICON nodes. It enables you to easily use ICON JSON-RPC APIs (opens in a new tab) (version 3). All methods of IconService returns a Request<T, ICError> instance.
Query Execution
Request are executed as synchronized and asynchronized.
Synchronized execution
To execute the request synchronously, you need to run execute() function of Request.
public func execute() -> Result<T, ICError>Returns
Result<T, ICError>
Example
// Synchronized request execution
let response = iconService.getLastBlock().execute()
switch response {
case .success(let block):
print(block)
case .failure(let error):
print(error.errorDescription)
}Asynchronized execution
To execute the request asynchronously, you need to run async() function of Request.
public func async(_ completion: @escaping (Result<T, ICError>) -> Void)Returns
async() is a closure. Passing Result<T, ICError>.
Example
// Asynchronized request execution
iconService.getLastBlock().async { (result) in
switch result {
case .success(let block):
print(block)
case .failure(let error):
print(err.errorDescription)
}
}Transaction Execution
Transaction class is used to make a transaction instance. There are 3 types of Transaction class.
| Class | Description |
|---|---|
| Transaction | A class for Transaction instance which is for sending ICX. |
| CallTransaction | A class for CallTransaction instance which is for SCORE function call. CallTransaction extends Transaction class. |
| MessageTransaction | A class for MessageTransaction instance which is for transfer message. Extends Transaction class. |
Request is executed as Synchronized or Asynchronized like a querying request.
Example
// Synchronized request
let response = iconService.sendTransaction(signedTransaction: signed).execute()
switch response {
case .success(let result): // result == String
print(result)
case .error(let error):
print(error)
}
// Asynchronized request
let request = iconService.sendTransaction(signedTransaction: signed)
request.async { (result) in
switch result {
case .success(let result): // result == String
print(result)
case .failure(let error):
print(error)
}
}Initialize
init(provider: String, nid: String)Parameters
| Parameter | Type | Description |
|---|---|---|
| provider | String | ICON node url. |
| nid | String | Network ID. |
For more details of node URL and network id, see ICON Network document.
Example
// ICON Mainnet
let iconService = ICONService(provider: "https://ctz.solidwallet.io/api/v3", nid: "0x1")func getLastBlock
Get the last block information.
func getLastBlock() -> Request<Response.Block>Parameters
None
Returns
Request - Request instance for icx_getLastBlock JSON-RPC API request. If the execution is successful, returns Result<Response.Block, ICError>.
Example
// Returns last block
let response = iconService.getLastBlock().execute()
switch response {
case .success(let result): // result == Response.Block
print(result)
case .error(let error):
print(error)
}func getBlock
Get the block information.
// Get block information by height.
func getBlock(height: UInt64) -> Request<Response.Block>
// Get block information by hash.
func getBlock(hash: String) -> Request<Response.Block>Parameters
| Parameter | Type | Description |
|---|---|---|
| height | UInt64 | Height value of block |
| hash | String | Hash value of block |
Returns
Request - Request instance for icx_getBlockByHeight | icx_getBlockByHash. If the execution is successful, returns Result<Response.Block, ICError>.
Example
// Returns block information by block height
let heightBlock = iconService.getBlock(height: 10532).execute()
// Returns block information by block hash
let hashBlock = iconService.getBlock(hash: "0xdb310dd653b2573fd673ccc7489477a0b697333f77b3cb34a940db67b994fd95").execute()
switch heightBlock {
case .success(let block): // result == Response.Block
print(block)
case .error(let error):
print(error)
}func call
Calls an external function of SCORE API.
func call<T>(_ call: Call<T>) -> Request<T>Parameters
| Parameter | Type | Description |
|---|---|---|
| call | Call | an instance of Call class. |
Returns
Request<T> - Request instance for icx_call JSON-RPC request. If the execution is successful, returns Result<T, ICError>.
Example
In Call generic value, input the type of function call. The generic value should follow Codable protocol.
For example, the type of SCORE function call is String, input String like this.
// Create Call instance
let call = Call<String>(from: wallet.address, to: "cxf9148db4f8ec78823a50cb06c4fed83660af38d0", method: "tokenOwner", params: nil)
let request: Request<String> = iconService.call(call)
let response: Result<String, ICError> = request.execute()
switch response {
case .success(let owner):
print(owner) // hx70b591822468415e86fb9ba1354214902ea76196
case .failure(let error):
print(error)
}If SCORE call result is hex String, you can choice return types String or BigUInt.
Using Call<String>, return an original hex String value.
Using Call<BigUInt> return converted BigUInt value.
let ownerAddress: String = "hx07abc7a5b8a4941fc0b6930c88b462995acf929b"
let scoreAddress: String = "cxf9148db4f8ec78823a50cb06c4fed83660af38d0"
// Using `String`. Return hex String.
let call = Call<String>(from: ownerAddress, to: scoreAddress, method: "balanceOf", params: ["_owner": ownerAddress])
let request: Request<String> = iconService.call(call)
let response: Result<String, ICError> = request.execute()
switch response {
case .success(let balance):
print("balance: \(balance)") // "balance: 0x11e468ef422cc60031ef"
case .failure(let error):
print(error)
}
// Using `BigUInt`. Return BigUInt.
let call = Call<BigUInt>(from: ownerAddress, to: scoreAddress, method: "balanceOf", params: ["_owner": ownerAddress])
let request: Request<BigUInt> = iconService.call(call)
let response: Result<BigUInt, ICError> = request.execute()
switch response {
case .success(let balance):
print("balance: \(balance)") // "balance: 84493649192649192649199"
case .failure(let error):
print(error)
}func getBalance
Get the balance of the address.
func getBalance(address: String) -> Request<BigUInt>Parameters
| Parameter | Type | Description |
|---|---|---|
| address | String | An EOA Address |
Returns
Request - Request instance for icx_getBalance JSON-RPC API request. If the execution is successful, returns Result<BigUInt, ICError>.
Example
// Returns the balance of specific address
let response = iconService.getBalance(address: "hx9d8a8376e7db9f00478feb9a46f44f0d051aab57").execute()
switch response {
case .success(let result): // result == BigUInt
print(result)
case .error(let error):
print(error)
}func getScoreAPI
Get the SCORE API list.
func getScoreAPI(scoreAddress: String) -> Request<[Response.ScoreAPI]>Parameters
| Parameter | Type | Description |
|---|---|---|
| scoreAddress | String | A SCORE address |
Returns
Request - Request instance for icx_getScoreApi JSON-RPC API request. If the execution is successful, returns Result<[Response.ScoreAPI], ICError>.
Example
// Returns the SCORE API list
let response = iconService.getScoreAPI(scoreAddress: "cx0000000000000000000000000000000000000001").execute()
switch response {
case .success(let result): // result == [Response.ScoreAPI]
print(result)
case .error(let error):
print(error)
}func getTotalSupply
get the total number of issued coins.
func getTotalSupply() -> Request<BigUInt>Parameters
None
Returns
Request - Request instance for icx_getTotalSupply JSON-RPC API request. If the execution is successful, returns Result<BigUInt, ICError>.
Example
// Returns total value of issued coins
let response = iconService.getTotalSupply().execute()
switch response {
case .success(let result): // result == BigUInt
print(result)
case .error(let error):
print(error)
}func getTransaction
Get the transaction information.
func getTransaction(hash: String) -> Request<Response.TransactionByHashResult>Parameters
| Parameter | Type | Description |
|---|---|---|
| hash | String | Hash value of transaction |
Returns
Request - Request instnace for icx_getTransactionByHash JSON-RPC API request. If the execution is successful, returns Result<Response.TransactionByHashResult, ICError>.
Example
// Returns transaction information
let response = iconService.getTransaction(hash: "0xb903239f8543d04b5dc1ba6579132b143087c68db1b2168786408fcbce568238").execute()
switch response {
case .success(let result): // result == Response.TransactionByHashResult
print(result)
case .error(let error):
print(error)
}func getTransactionResult
Get the transaction result information.
func getTransactionResult(hash: String) -> Request<Response.TransactionResult>Parameters
| Parameter | Type | Description |
|---|---|---|
| hash | String | A transaction hash. |
Returns
Request - Request instance for icx_getTransactionResult JSON-RPC API request. If the execution is successful, returns Result<Response.TransactionResult, ICError>.
Example
// Returns transaction result information
let response = iconService.getTransactionResult(hash: "0xb903239f8543d04b5dc1ba6579132b143087c68db1b2168786408fcbce568238").execute()
switch response {
case .success(let result): // result == Response.TransactionResult
print(result)
case .error(let error):
print(error)
}func sendTransaction
Send a transaction that changes the state of address. Request is executed as Synchronized or Asynchronized like a querying request.
func sendTransaction(signedTransaction: SignedTransaction) -> Request<String>Parameters
| Parameter | Type | Description |
|---|---|---|
| signedTransaction | SignedTransaction | an instance of SignedTransaction class. |
Returns
Request - Request instance for icx_sendTransaction JSON-RPC request. If the execution is successful, returns Result<String, ICError>.
Example
// Synchronized request
let response = iconService.sendTransaction(signedTransaction: signed).execute()
switch response {
case .success(let result): // result == String
print(result)
case .error(let error):
print(error)
}
// Asynchronized request
let request = iconService.sendTransaction(signedTransaction: signed)
request.async { (result) in
switch result {
case .success(let result): // result == String
print(result)
case .failure(let error):
print(error)
}
}class Wallet
class WalletA class which provides EOA functions. It enables you to create, transform to Keystore or load wallet from Keystore.
Initialize
init(privateKey: PrivateKey?)Parameters
| Parameter | Type | Description |
|---|---|---|
| privateKey | PrivateKey | If privateKey is null, it generates new private key while initializing. |
Returns
Wallet - Wallet instance.
Example
// Create new wallet
let wallet = Wallet(prviateKey: nil) // will generate private key
// Imports from exist private key
let privateKey = PrivateKey(hexData: privateKeyData)
let wallet = Wallet(privateKey: privateKey)// Loading wallets and storing the Keystore
// Save wallet keystore.
let wallet = Wallet(privateKey: nil)
do {
try wallet.generateKeystore(password: "YOUR_WALLET_PASSWORD")
try wallet.save(filepath: "YOUR_STORAGE_PATH")
} catch {
// handle errors
}
// Load a wallet from the keystore.
do {
let jsonData: Data = try Data(contentsOf: "YOUR_KEYSTORE_PATH")
let decoder = JSONDecoder()
let keystore = try decoder.decoder(Keystore.self, from: jsonData)
let wallet = Wallet(keystore: keystore, password: "YOUR_WALLET_PASSWORD")
} catch {
// handle errors
}func getSignature
Generate signature string by signing transaction data.
func getSignature(data: Data) throws -> StringParameter
| Parameter | Type | Description |
|---|---|---|
| data | Data | the serialized transaction data. |
Returns
String - A signature string.(Base64 encoded)
Example
let wallet = Wallet(privateKey: nil)
do {
let signature = try wallet.getSignature(data: toBeSigned)
print("signature - \(signature)")
} catch {
// handle error
}Properties
| Property | Type | Description |
|---|---|---|
| address | String | Return wallet's address (read-only) |
class Transaction
class TransactionTransaction is a class representing a transaction data used for sending ICX.
Initialize
// Create empty transaction object
init()
// Create transaction with data
convenience init(from: String, to: String, stepLimit: BigUInt, nid: String, value: BigUInt, nonce: String, dataType: String? = nil, data: Any? = nil)Parameters
| Parameter | Description |
|---|---|
| from | An EOA address that creates the transaction. |
| to | An EOA address to receive coins or SCORE address to execute the transaction. |
| stepLimit | Amounts of Step limit. |
| nid | A network ID. |
| value | Sending the amount of ICX in loop unit. |
| nonce | An arbitrary number used to prevent transaction hash collision. |
func from
Setter for from property.
func from(_ from: String) -> SelfParameters
| Parameter | Type | Description |
|---|---|---|
| from | String | An EOA address that creates the transaction. |
Returns
Returns Transaction itself.
Example
// Set from property
let transaction = Transaction()
.from("hx9043346dbaa72bca42ecec6b6e22845a4047426d")func to
Setter for to property.
func to(_ to: String) -> SelfParamters
| Paramter | Type | Description |
|---|---|---|
| to | String | An EOA or SCORE address. |
Returns
Returns Transaction itself.
Example
let transaction = Transaction()
.to("hx2e26d96bd7f1f46aac030725d1e302cf91420458")func stepLimit
Setter for setpLimit property.
func stepLimit(_ limit: BigUInt) -> SelfParameters
| Parameter | Type | Description |
|---|---|---|
| limit | BigUInt | Amounts of Step limit |
Returns
Returns Transaction itself.
Example
let transaction = Transaction()
.stepLimit(BigUInt(1000000))func nid
Setter for nid property.
func nid(_ nid: String) -> SelfParameters
| Parameter | Type | Description |
|---|---|---|
| nid | String | A network ID. (Mainnet = "0x1", Testnet = "0x2", etc) |
Returns
Returns Transaction itself.
Example
let transaction = Transaction()
.nid("0x1")func value
Setter for value property.
func value(_ value: BigUInt) -> SelfParameters
| Parameter | Type | Description |
|---|---|---|
| value | BigUInt | Sending amount of ICX in loop unit. (1 ICX = 1018 loop) |
Returns
Returns Transaction itself.
Example
let transaction = Transaction()
.value(BigUInt(15000000))func nonce
Setter for nonce property.
func nonce(_ nonce: String) -> SelfParameters
| Parameter | Type | Description |
|---|---|---|
| nonce | String | A nonce value. |
Returns
Returns Transaction itself.
Example
let transaction = Transaction()
.nonce("0x1")// Creating transaction instance for Sending ICX.
let transaction = Transaction()
.from("hx9043346dbaa72bca42ecec6b6e22845a4047426d")
.to("hx2e26d96bd7f1f46aac030725d1e302cf91420458")
.value(BigUInt(15000000))
.stepLimit(BigUInt(1000000))
.nid("0x1")
.nonce("0x1")class CallTransaction
class CallTransaction: TransactionCallTransaction class is used for invoking a state-transition function of SCORE. It extends Transaction class, so instance parameters and methods of the class are mostly identical to Transaction class, except for the following:
Parameters
| Parameters | Description |
|---|---|
| method | The method name of SCORE API. |
| params | The input params for method. |
For details of extended parameters and methods, see Transaction section.
func method
Transaction for invoking a state-transition function of SCORE.
Transaction parameter dataType will be fixed with call
func method(_ method: String) -> SelfParameters
| Parameter | Type | Description |
|---|---|---|
| method | String | the method name of SCORE API. |
Returns
Returns CallTransaction itself.
params
The input parameters of the SCORE method that will be executed by call function.
func params(_ params: [String: Any]) -> SelfParameter
| Parameter | Type | Description |
|---|---|---|
| params | Dictionary<String: Any> | Input parameters for call method. |
Returns
Returns CallTransaction itself.
Example
// Creating transaction instance for SCORE function call
let call = CallTransaction()
.from(wallet.address)
.to("cx000...001")
.stepLimit(BigUInt(1000000))
.nid(self.iconService.nid)
.nonce("0x1")
.method("transfer")
.params(["_to": to, "_value": "0x1234"])class MessageTransaction
class MessageTransaction: TransactionMessageTransaction class is used for sending message data. It extends Transaction class, so instance parameters and methods of the class are mostly identical to Transaction class, except for the following:
Parameters
| Parameters | Description |
|---|---|
| message | A message to send. |
For details of extended parameters and methods, see Transaction section.
func message
Send messages.
Transaction parameter dataType will be fixed with message.
func message(_ message: String) -> SelfParameters
| Parameter | Type | Description |
|---|---|---|
| message | String | A message String. |
Returns
Returns MessageTransaction itself.
Example
// Creating transaction instance for transfering message.
let messageTransaction = MessageTransaction()
.from("hx9043346dbaa72bca42ecec6b6e22845a4047426d")
.to("hx2e26d96bd7f1f46aac030725d1e302cf91420458")
.value(BigUInt(15000000))
.stepLimit(BigUInt(1000000))
.nonce("0x1")
.nid("0x1")
.message("Hello, ICON!")class SignedTransaction
SignedTransaction is a class to make a signed transaction.
Initialize
init(transaction: Transaction, privateKey: PrivateKey)Parameters
| Parameter | Type | Description |
|---|---|---|
| transaction | Transaction | A transaction that will be signed. |
| privateKey | PrivateKey | A privateKey. |
Example
let signed = try SignedTransaction(transaction: transaction, privateKey: yourPrivateKey)ICError
There are 5 types of errors.
- emptyKeystore - Keystore is empty.
- invalid
- missing(parameter: JSONParameterKey) - Missing JSON parameter.
- malformedKeystore - Keystore data malformed.
- wrongPassword - Wrong password.
- fail
- sign - Failed to sign.
- parsing - Failed to parse.
- decrypt - Failed to decrypt.
- convert - Failed to convert to URL or data.
- error(error: Error)
- message(error: String) - JSON RPC Error Messages (opens in a new tab)
Converter Functions
ICONKit supports converter functions.
convert()
Convert ICX or gLoop to loop.
1 ICX = 109 gLoop = 1018 loop
Paramters
| Parameters | Type | Description |
|---|---|---|
| unit | Unit | The unit of value( .icx, .gLoop, .loop ). Default value is .icx. |
Returns
BigUInt - The value that converted to loop.
Example
let balance: BigUInt = 100
// Convert ICX to loop.
let ICXToLoop: BigUInt = balance.convert() // 100000000000000000000
// Convert gLoop to loop
let gLoopToLoop: BigUInt = balance.convert(unit: .gLoop) // 100000000000toHexString()
Convert BigUInt value to hex String.
public func toHexString(unit: Unit = .loop) -> StringParameters
| Parameters | Type | Description |
|---|---|---|
| unit | Unit | The unit of value( .icx, .gLoop, .loop ). Default value is .loop. |
Returns
String - The value converted to a hex String.
Example
// Convert `BigUInt` value to hex `String`.
let ICXToLoop: BigUInt = 100000000000000000000
let hexString: String = ICXToLoop.toHexString() // 0x56bc75e2d63100000hexToBigUInt()
Convert hex String to BigUInt.
public func hexToBigUInt(unit: Unit = .loop) -> BigUInt?Parameters
| Parameters | Type | Description |
|---|---|---|
| unit | Unit | The unit of value( .icx, .gLoop, .loop ). Default value is .loop. |
Returns
BigUInt - The value that converted to hex String.
If the conversion is failed, return nil.
Example
// Convert hex `String` to `BigUInt`.
let hexString: String = "0x56bc75e2d63100000"
let hexBigUInt: BigUInt = hexString.hexToBigUInt()! // 100000000000000000000