# Blockchain functions

Name	Description	Complexity
addressFromRecipient(Address\|Alias): Address	Gets the corresponding address of the alias	5
assetBalance(Address\|Alias, ByteVector): Int	Gets account balance by token ID	10
assetInfo(ByteVector): Asset\|Unit	Gets the information about a token	15
blockInfoByHeight(Int): BlockInfo\|Unit	Gets the information about a block by the block height	5
calculateAssetId(Issue): ByteVector	Calculates ID of the token formed by the Issue structure when executing the callable function	10
calculateLeaseId(Lease): ByteVector	Calculates ID of the lease formed by the Lease structure when executing the callable function	1
scriptHash(Address\|Alias): ByteVector\|Unit	Returns BLAKE2b-256 (opens new window) hash of the script assigned to a given account	200
transactionHeightById(ByteVector): Int\|Unit	Gets the block height of a transaction	20
transferTransactionById(ByteVector): TransferTransaction\|Unit	Gets the data of a transfer transaction	60
wavesBalance(Address\|Alias): BalanceDetails	Gets account balance in WAVES	10

# addressFromRecipient(Address|Alias): Address

Gets the corresponding address of the alias.

addressFromRecipient(AddressOrAlias: Address|Alias): Address

For a description of the return value, see the Address article.

# Parameters

Parameter	Description
AddressOrAlias: Address\|Alias
Address or alias, usually tx.recipient

# Examples

let address =Address(base58'3NADPfTVhGvVvvRZuqQjhSU4trVqYHwnqjF')
addressFromRecipient(address)

# assetBalance

Gets account balance by token ID.

assetBalance(addressOrAlias: Address|Alias, assetId: ByteVector): Int

# Parameters

Parameter	Description
addressOrAlias: Address\|Alias	Address or alias of the account
assetId: ByteVector	Token ID

# assetInfo

Gets the information about a token.

assetInfo(id: ByteVector): Asset|Unit

For a description of the return value, see the Asset article.

# Parameters

Parameter	Description
`id`: ByteVector	ID of the token

# Example

let bitcoinId = base58'8LQW8f7P5d5PZM7GtZEBgaqRPGSzS3DfPuiXrURJ4AJS'
let x = match assetInfo(bitcoinId) {
    case asset:Asset =>
        asset.decimals # 8
    case _ => throw("Can't find asset")
}

# blockInfoByHeight

Gets the information about a block by the block height.

blockInfoByHeight(height: Int): BlockInfo|Unit

For a description of the return value, see the BlockInfo article.

# Parameters

Parameter	Description
`height`: Int	Block height

# Example

let x = match blockInfoByHeight(1234567) {
    case block:BlockInfo =>
        block.generator.toString() # "3P38Z9aMhGKAWnCiyMW4T3PcHcRaTAmTztH"
    case _ => throw("Can't find block")
}

# calculateAssetId

Calculates ID of the token formed by the Issue structure when executing the callable function.

calculateAssetId(issue: Issue): ByteVector

# Parameters

Parameter	Description
`issue`: Issue	Structure that sets the parameters of the token issue

# Example

{-# STDLIB_VERSION 5 #-}
{-# CONTENT_TYPE DAPP #-}
{-# SCRIPT_TYPE ACCOUNT #-}
  
@Callable(inv)
func issueAndId() = {
  let issue = Issue("CryptoRouble", "Description", 1000, 2, true)
  let id = calculateAssetId(issue)
  (
    [
      issue,
      BinaryEntry("id", id)
    ],
    unit
  )
}

# calculateLeaseId

Calculates ID of the lease formed by the Lease structure when executing the callable function.

calculateLeaseId(lease: Lease): ByteVector

# Parameters

Parameter	Description
`lease`: Lease	Structure that sets the lease parameters

# Example

{-# STDLIB_VERSION 5 #-}
{-# CONTENT_TYPE DAPP #-}
{-# SCRIPT_TYPE ACCOUNT #-}
  
@Callable(i)
func foo() = {
  let lease = Lease(Alias("merry"),100000000)
  let id = calculateLeaseId(lease)
  (
    [
      lease,
      BinaryEntry("lease", id)
    ],
    unit
  )
}

# scriptHash

Returns BLAKE2b-256 (opens new window) hash of the script assigned to a given account. Returns unit if there is no script.

The function can be used to verify that the script is exactly the same as expected.

scriptHash(addressOrAlias: Address|Alias): ByteVector|Unit

# Parameters

Parameter	Description
`addressOrAlias`: Address\|Alias	Address or alias of the account

# Example

let addr = Address(base58'3MxBZbnN8Z8sbYjjL5N3oG5C8nWq9NMeCEm')

scriptHash(addr) # Returns base58'G6ihnWN5mMedauCgNa8TDrSKWACPJKGQyYagmMQhPuja'

# transactionHeightById

Gets the block height of a transaction.

transactionHeightById(id: ByteVector): Int|Unit

# Parameters

Parameter	Description
`id`: ByteVector	ID of the transaction

# Example

let bitcoinId = base58'8LQW8f7P5d5PZM7GtZEBgaqRPGSzS3DfPuiXrURJ4AJS'
let x = match transactionHeightById(bitcoinId) {
    case h:Int => h # 257457
    case _ => throw("Can't find transaction")
}

# transferTransactionById

Gets the data of a transfer transaction.

transferTransactionById(id: ByteVector): TransferTransaction|Unit

For a description of the return value, see the TransferTransaction article.

# Parameters

Parameter	Description
`id`: ByteVector	ID of the transfer transaction

# Example

let transferId = base58'J2rcMzCWCZ1P3SFZzvz9PR2NtBjomDh57HTcqptaAJHK'
let x = match transferTransactionById(transferId) {
    case ttx:TransferTransaction =>
        ttx.amount # 3500000000
    case _ => throw("Can't find transaction")
}

# wavesBalance

Gets all types of WAVES balances. For description of balance types, see the Account Balance article.

wavesBalance(addressOrAlias: Address|Alias): BalanceDetails

For a description of the return value, see the BalanceDetails article.

# Parameters

Parameter	Description
addressOrAlias: Address\|Alias	Address or alias of the account