modules/ROOT/pages/modules/tx-control/advancedScopes.adoc

= Advanced Scope control

There are a number of useful ways to interact with the scopes created by the Transaction Control Service

== Determining the current scope

The Transaction Control Service has methods which can be used to work out whether a scope is in effect:

* `txControl.activeScope();` - When `true` there is a scope in effect and resources can be  accessed.
The scope may, or may not, be transactional.
When false there is no current scope and `txControl.getCurrentContext();` will return `null`.
* `txControl.activeTransaction()` - When `true` there is a transactional scope in  effect and resources can be accessed transactionally.
When false there may, or may not, be a "No Transaction" scope in effect.

Note that `assert txControl.activeTransaction();` can be used to enforce the presence of a transaction.
This is equivalent to a "Mandatory" transaction in Spring or Java EE.

== Avoiding rollback

When setting up a transaction certain exception types can be marked as not triggering rollback:

 txControl.build()
     .noRollbackFor(MyCustomException.class)
     .required(() -> {
             // A MyCustomException thrown here will not trigger rollback
         });

== Nesting a transaction

Nesting a Transaction can easily be managed using `requiresNew()`

 txControl.required(() -> {
         // Do some work...

         return txControl.requiresNew(() -> {
                 // Do some more work
             });
     });

== Suspending a transaction

Suspending a Transaction can easily be managed using `notSupported()`

 txControl.required(() -> {
         // Do some work...

         return txControl.notSupported(() -> {
                 // Do some more work
             });
     });