Package com.daml.ledger.javaapi.data.codegen

Class ContractTypeCompanion<Ct,Id,ContractType,Data>

java.lang.Object

com.daml.ledger.javaapi.data.codegen.ContractTypeCompanion<Ct,Id,ContractType,Data>

Type Parameters:

Ct - The specific type of Contract representing contracts from the ledger. Always a subtype of Contract<Id, Data>.

Id - The code-generated class of ContractIds specific to this template or interface. Always a subtype of ContractId<ContractType>.

ContractType - The type argument to ContractIds of this contract type. This is the same as Data for templates, but is a pure marker type for interfaces.

Data - The "payload" data model for a contract. This is the template payload for templates, and the view type for interfaces.

Direct Known Subclasses:

ContractCompanion, InterfaceCompanion

public abstract class ContractTypeCompanion<Ct,Id,ContractType,Data>
extends java.lang.Object

The commonality between ContractCompanion and InterfaceCompanion.

Field Summary

Fields

Modifier and Type	Field	Description
java.util.Map<java.lang.String,Choice<ContractType,?,?>>	choices	The provides a mapping of choice name to Choice.
Identifier	TEMPLATE_ID	The full template ID of the template or interface that defined this companion.

Method Summary

Modifier and Type	Method	Description
abstract Ct	fromCreatedEvent(CreatedEvent event)	Tries to parse a contract from an event expected to create a Ct contract.
Id	toContractId(ContractId<ContractType> parameterizedContractId)	Convert from a generic ContractId to the specific contract ID subclass generated as part of this companion's template or interface.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

TEMPLATE_ID

public final Identifier TEMPLATE_ID

The full template ID of the template or interface that defined this companion.

choices

public final java.util.Map<java.lang.String,Choice<ContractType,?,?>> choices

The provides a mapping of choice name to Choice.

 // if you statically know the name of a choice
 var c1 = Bar.COMPANION.choices.get("Transfer");
 // it is better to retrieve it directly from the generated field
 var c2 = Bar.CHOICE_Transfer;
 

Method Detail

fromCreatedEvent

public abstract Ct fromCreatedEvent(CreatedEvent event)
                             throws java.lang.IllegalArgumentException

Tries to parse a contract from an event expected to create a Ct contract. This is either the CreatedEvent.getArguments() for ContractCompanion, or one of CreatedEvent.getInterfaceViews() for an InterfaceCompanion.

Parameters:

event - the event to try to parse a contract from

Returns:

The parsed contract, with payload and metadata, if present.

Throws:

java.lang.IllegalArgumentException - when the CreatedEvent payload cannot be parsed as Data, or the CreatedEvent.getContractKey() cannot be parsed as a contract key.

toContractId

public final Id toContractId(ContractId<ContractType> parameterizedContractId)

Convert from a generic ContractId to the specific contract ID subclass generated as part of this companion's template or interface. Most applications should not need this function, but if your Daml data types include types like ContractId t where t is any type parameter, that is likely to result in code-generated types like ContractId<t> that need to be passed to this function before e.g. exercise* methods can be used.