TransactionQueue

Class to manage procedural transaction queues

Type parameters

▪ ProcedureReturnType

▪ ReturnType

▪ TransactionArgs: unknown[][]

Hierarchy

• TransactionQueue

Index

Constructors

• constructor

Properties

• error

• status

• transactions

Methods

• getMinFees

• onProcessedByMiddleware

• onStatusChange

• onTransactionStatusChange

• run

Constructors

constructor

+ new TransactionQueue(args: object, context: Context): TransactionQueue

Defined in src/base/TransactionQueue.ts:91

Create a transaction queue

Parameters:

▪ args: object

Name	Type	Description
procedureResult	MaybePostTransactionValue‹ProcedureReturnType›	value that will be returned by the queue after it is run. It can be a [[PostTransactionValue]]
transactions	PolymeshTransactionArray‹TransactionArgs›	list of transactions to be run in this queue
transformer?	undefined | function	function that transforms the procedure's return value before returning it after the queue is run

▪ context: Context

Returns: TransactionQueue

Properties

Optional error

• error? : PolymeshError

Defined in src/base/TransactionQueue.ts:59

optional error information

---

status

• status: TransactionQueueStatus = TransactionQueueStatus.Idle

Defined in src/base/TransactionQueue.ts:54

status of the queue

---

transactions

• transactions: PolymeshTransactionArray‹TransactionArgs›

Defined in src/base/TransactionQueue.ts:49

transactions that will be run in the queue

Methods

getMinFees

▸ getMinFees(): Promise‹FeesBreakdown›

Defined in src/base/TransactionQueue.ts:189

Retrieves a lower bound of the fees required to execute this transaction queue. Transaction fees can be higher at execution time for three reasons:

• One or more transaction arguments depend on the result of another transaction in the queue. This means fees can't be calculated for said transaction until previous transactions in the queue have run

• Protocol or gas fees may vary between when this value is fetched and when the transaction is actually executed because of a governance vote

Transaction fees are broken down between those that have to be paid by the current Account and those that will be paid by third parties. In most cases, the entirety of the fees will be paid by either the current Account or a single third party Account

Returns: Promise‹FeesBreakdown›

---

onProcessedByMiddleware

▸ onProcessedByMiddleware(listener: function): function

Defined in src/base/TransactionQueue.ts:319

Subscribe to the results of this queue being processed by the harvester (and as such, available to the middleware)

note this event will be fired even if the queue fails

throws if the middleware wasn't enabled when instantiating the SDK client

Parameters:

▪ listener: function

callback function that will be called whenever the middleware is updated with the latest data. If there is an error (timeout or middleware offline) it will be passed to this callback

▸ (err?: PolymeshError): void

Parameters:

Name	Type
err?	PolymeshError

Returns: function

unsubscribe function

▸ (): void

---

onStatusChange

▸ onStatusChange(listener: function): function

Defined in src/base/TransactionQueue.ts:282

Subscribe to status changes on the Transaction Queue

Parameters:

▪ listener: function

callback function that will be called whenever the Transaction Queue's status changes

▸ (transactionQueue: this, err?: PolymeshError): void

Parameters:

Name	Type
transactionQueue	this
err?	PolymeshError

Returns: function

unsubscribe function

▸ (): void

---

onTransactionStatusChange

▸ onTransactionStatusChange‹TxArgs, Values›(listener: function): function

Defined in src/base/TransactionQueue.ts:299

Subscribe to status changes on individual transactions

Type parameters:

▪ TxArgs: unknown[]

▪ Values: unknown[]

Parameters:

▪ listener: function

callback function that will be called whenever the individual transaction's status changes

▸ (transaction: PolymeshTransactionBase‹TxArgs, Values›, transactionQueue: this): void

Parameters:

Name	Type
transaction	PolymeshTransactionBase‹TxArgs, Values›
transactionQueue	this

Returns: function

unsubscribe function

▸ (): void

---

run

▸ run(): Promise‹ReturnType›

Defined in src/base/TransactionQueue.ts:136

Run the transactions in the queue in sequential order. If a transaction fails or the user refuses to sign it, one of two things can happen:

1. If transaction.isCritical === true, the entire queue fails and the corresponding error is stored in this.error as well as thrown

2. Otherwise, the queue continues executing and the error is stored in transaction.error

Returns: Promise‹ReturnType›