LinearPointer - corda

corda / net.corda.core.contracts / LinearPointer

# LinearPointer

`class LinearPointer<T : LinearState> : StatePointer<T>`

LinearPointer allows a ContractState to "point" to another LinearState creating a "many-to-one" relationship between all the states containing the pointer to a particular LinearState and the LinearState being pointed to. Using the LinearPointer is useful when one state depends on the data contained within another state that evolves independently. When using LinearPointer it is worth noting:

- The node performing the resolution may not have seen any LinearStates with the specified linearId, as such the vault query in resolve will return null and resolve will throw an exception
- The node performing the resolution may not have the latest version of the LinearState and therefore will return an older version of the LinearState. As the pointed-to state will be added as a reference state to the transaction then the transaction with such a reference state cannot be committed to the ledger until the most up-to-date version of the LinearState is available. See reference states documentation on docs.corda.net for more info.

### Constructors

#### <init> | Allows this class to be evolved through backwards compatibility with version 1 of this class. `LinearPointer(pointer: UniqueIdentifier, type: Class<T>)` LinearPointer allows a ContractState to "point" to another LinearState creating a "many-to-one" relationship between all the states containing the pointer to a particular LinearState and the LinearState being pointed to. Using the LinearPointer is useful when one state depends on the data contained within another state that evolves independently. When using LinearPointer it is worth noting: `LinearPointer(pointer: UniqueIdentifier, type: Class<T>, isResolved: Boolean = true)`

### Properties

#### isResolved | Determines whether the state pointer should be resolved to a reference input when used in a transaction. `val isResolved: Boolean`
#### pointer | An identifier for the ContractState that this StatePointer points to. `val pointer: UniqueIdentifier`
#### type | Type of the state which is being pointed to. `val type: Class<T>`

### Functions

#### equals | `fun equals(other: Any?): Boolean`
#### hashCode | `fun hashCode(): Int`
#### resolve | Resolves a LinearPointer using the UniqueIdentifier contained in the pointer property. Returns a StateAndRef containing the latest version of the LinearState that the node calling resolve is aware of. `fun resolve(services: ServiceHub): StateAndRef<T>` Resolves a StatePointer to a StateAndRef from inside a LedgerTransaction. The intuition here is that all of the pointed-to states will be included in the transaction as reference states. `fun resolve(ltx: LedgerTransaction): StateAndRef<T>`