Transaction Events

Transactional Events

BoxLang emits events during the lifecycle of a JDBC transaction which can be used to react to various transaction points in your app:

• onTransactionBegin

• onTransactionEnd

• onTransactionCommit

• onTransactionRollback

• onTransactionSetSavepoint

• onTransactionAcquire*

• onTransactionRelease*

Note that all these events (with the exception of onTransactionAcquire and onTransactionRelease) have the potential to be acting upon a no-op transaction, with a null connection parameter since no connection was ever obtained. ( Read more in Transaction Behavior for a description of how transactions work. )

With this in mind, you'll want to do null checks against the connection parameter in case no connection has yet been acquired:

function onTransactionSetSavepoint( struct data ){
    if( data.keyExists( "connection" ) && data.connection != null ){
        // we can be sure this transaction is "doing work".
    }
}

The two exceptions, as mentioned above, are onTransactionAcquire and onTransactionRelease, which only emit once a connection has been acquired, and is being released, respectively. Most of the time you'll want to listen for these events instead of their onTransactionBegin/onTransactionEnd counterparts.

onTransactionBegin

This event fires when the transaction block is first opened and before the body begins processing.

Note that in BoxLang transactions, no connection is acquired until the first JDBC query is executed. This means that the onTransactionBegin will not have any connection to operate on. Most of the time, you will want to use onTransactionAcquire in place of onTransactionBegin.

Data Key	Type	Description
transaction	Java class	Instance of the Transaction object

Example

function onTransactionBegin( struct data ){}

onTransactionEnd

This event fires when the transaction block is closed after the body has finished processing.

Consider using onTransactionRelease as an alternative to onTransactionEnd if you only want to listen for transactions that have done work.

Data Key	Type	Description
transaction	Java class	Instance of the Transaction object
connection	Java class	Instance of the java.sql.Connection object this transaction is operating upon. May be null if no JDBC queries have executed inside this transaction.

Example

function onTransactionEnd( struct data ){}

onTransactionAcquire

This event fires when the transaction first acquires a connection due to a JDBC query being executed within the body. You should prefer this over onTransactionBegin.

Data Key	Type	Description
transaction	Java class	Instance of the Transaction object
connection	Java class	Instance of the java.sql.Connection object this transaction is operating upon

Example

function onTransactionAcquire( struct data ){}

onTransactionRelease

This event fires when the transaction releases its connection. You should prefer this over onTransactionEnd.

Data Key	Type	Description
transaction	Java class	Instance of the Transaction object
connection	Java class	Instance of the java.sql.Connection object this transaction is operating upon

Example

function onTransactionRelease( struct data ){}

onTransactionCommit

This event fires when a transaction commit action occurs. Can occur multiple times (or never) within a single transaction.

Data Key	Type	Description
transaction	Java class	Instance of the Transaction object
connection	Java class	Instance of the java.sql.Connection object this transaction is operating upon

Example

function onTransactionCommit( struct data ){}

onTransactionRollback

This event fires when a transaction rollback action occurs. Can occur multiple times (or never) within a single transaction.

Data Key	Type	Description
transaction	Java class	Instance of the Transaction object
connection	Java class	Instance of the java.sql.Connection object this transaction is operating upon
savepoint	String	Savepoint name to roll back to. May be null.

Example

function onTransactionRollback( struct data ){}

onTransactionSetSavepoint

This event fires when a transaction savepoint is set.

Data Key	Type	Description
transaction	Java class	Instance of the Transaction object
connection	Java class	Instance of the java.sql.Connection object this transaction is operating upon
savepoint	String	Savepoint name to set.

Example

function onTransactionSetSavepoint( struct data ){}