UpgradedContract - corda

corda / net.corda.core.contracts / UpgradedContract

# UpgradedContract

`interface UpgradedContract<in OldState : ContractState, out NewState : ContractState> : Contract`

Interface which can upgrade state objects issued by a contract to a new state object issued by a different contract. The upgraded contract should specify the legacy contract class name, and provide an upgrade function that will convert legacy contract states into states defined by this contract.

In addition to the legacy contract class name, you can also specify the legacy contract constraint by implementing UpgradedContractWithLegacyConstraint instead. Otherwise, the default WhitelistedByZoneAttachmentConstraint will be used for verifying the validity of an upgrade transaction.

### Parameters

`OldState` - the old contract state (can be ContractState or other common supertype if this supports upgrading more than one state).

`NewState` - the upgraded contract state.

### Properties

#### legacyContract | Name of the contract this is an upgraded version of, used as part of verification of upgrade transactions. `abstract val legacyContract: ContractClassName`

### Functions

#### upgrade | Upgrade contract's state object to a new state object. `abstract fun upgrade(state: OldState): NewState`

### Inheritors

#### UpgradedContractWithLegacyConstraint | This interface allows specifying a custom legacy contract constraint for upgraded contracts. The default for UpgradedContract is WhitelistedByZoneAttachmentConstraint. `interface UpgradedContractWithLegacyConstraint<in OldState : ContractState, out NewState : ContractState> : UpgradedContract<OldState, NewState>`