com.r3corda.core.contracts / ContractState

ContractState

interface ContractState

A contract state (or just "state") contains opaque data used by a contract program. It can be thought of as a disk file that the program can use to persist data across transactions. States are immutable: once created they are never updated, instead, any changes must generate a new successor state. States can be updated (consumed) only once: the notary is responsible for ensuring there is no "double spending" by only signing a transaction if the input states are all free.



Properties

contract abstract val contract: Contract

An instance of the contract class that will verify this state.

encumbrance open val encumbrance: Int?

All contract states may be encumbered by up to one other state.

participants abstract val participants: List<PublicKey>

A participant is any party that is able to consume this state in a valid transaction.

Extension Functions

hash fun ContractState.hash(): SecureHash

Returns the SHA-256 hash of the serialised contents of this state (not cached)

with notary infix fun <T : ContractState> T.with notary(newNotary: Party): TransactionState<T>

Wraps the ContractState in a TransactionState object

withNotary infix fun <T : ContractState> T.withNotary(newNotary: Party): TransactionState<T>

Inheritors

DummyState data class DummyState : ContractState

Dummy state for use in testing. Not part of any contract, not even the DummyContract.

LinearState interface LinearState : ContractState

A state that evolves by superseding itself, all of which share the common "linearId".

MultiOwnerState data class MultiOwnerState : ContractState, State

Alternative state with multiple owners. This exists primarily to provide a dummy state with multiple participants, and could in theory be merged with SingleOwnerState by putting the additional participants in a different field, however this is a good example of a contract with multiple states.

OwnableState interface OwnableState : ContractState

A contract state that can have a single owner.

QueryableState interface QueryableState : ContractState

A contract state that may be mapped to database schemas configured for this node to support querying for, or filtering of, states.

SchedulableState interface SchedulableState : ContractState
State interface State : ContractState