scopes.md

Scopes & Late Binding

Scopes allow late-binding of values to step/job-scoped components at execution time.

Scope Classes

Class	Namespace
AbstractScope	Lemric\BatchProcessing\Scope
JobScope	Lemric\BatchProcessing\Scope
StepScope	Lemric\BatchProcessing\Scope

Scope Containers

A scoped container resolves and caches scoped beans for the lifetime of a single execution:

Class	Namespace
ScopedContainerInterface	Lemric\BatchProcessing\Scope\Container
InMemoryScopedContainer	Lemric\BatchProcessing\Scope\Container

Expression Resolution

Late-binding expressions reference job parameters or execution context values:

Class	Namespace
LateBindingExpressionResolverInterface	Lemric\BatchProcessing\Scope\Expression
SimpleLateBindingExpressionResolver	Lemric\BatchProcessing\Scope\Expression

The simple resolver supports placeholders that reference parameters / context values; refer to the class for the exact syntax supported in your version.

Attributes

Attribute	Purpose
Lemric\BatchProcessing\Attribute\JobScope	Marks a class as JobScope
Lemric\BatchProcessing\Attribute\StepScope	Marks a class as StepScope
Lemric\BatchProcessing\Attribute\Listener\*	Listener attribute markers

use Lemric\BatchProcessing\Attribute\StepScope;

#[StepScope]
final class PartitionAwareReader implements ItemReaderInterface
{
    public function __construct(
        private readonly int $minValue,
        private readonly int $maxValue,
    ) {}

    public function read(): mixed { /* ... */ }
}

Scope Lifecycle

1. Activation — when a Job/Step starts, its scope is activated and a fresh ScopedContainer is bound.
2. Resolution — scoped beans are resolved (or rebuilt) on first access from inside the active scope.
3. Deactivation — when the Job/Step ends, the scope is deactivated and resolved beans are released.

Accessing a scoped bean outside its active scope throws Lemric\BatchProcessing\Exception\ScopeNotActiveException.

Reset Listener

Lemric\BatchProcessing\Listener\ScopeResetListener clears the scoped container between runs to avoid leaking state across executions.

Next Steps

• Symfony Bridge
• Partition & Parallel Processing