Lifecycle Management

PHP Event Sourcing Projection Lifecycle and CLI

The Problem

Your projection's table schema changed, or you found a bug in a handler and the read model has wrong data. How do you set up, tear down, and rebuild projections without writing manual SQL scripts?

Ecotone provides lifecycle hooks — methods on your projection class that are called at specific moments — and CLI commands to trigger them.

Lifecycle Hooks

Initialization

Called when the projection is first set up. Use it to create tables, indexes, or any storage structure:

#[ProjectionInitialization]
public function init(): void
{
    $this->connection->executeStatement(<<<SQL
        CREATE TABLE IF NOT EXISTS ticket_list (
            ticket_id VARCHAR(36) PRIMARY KEY,
            ticket_type VARCHAR(25),
            status VARCHAR(25)
        )
    SQL);
}

By default, projections auto-initialize on the first event trigger. You don't need to run initialization manually unless you use #[ProjectionDeployment(manualKickOff: true)].

Delete

Called when the projection is permanently removed. Clean up all storage:

#[ProjectionDelete]
public function delete(): void
{
    $this->connection->executeStatement('DROP TABLE IF EXISTS ticket_list');
}

Reset

Called when the projection needs to be rebuilt from scratch. Clear the data but keep the structure:

#[ProjectionReset]
public function reset(): void
{
    $this->connection->executeStatement('DELETE FROM ticket_list');
}

After a reset, the projection's position is set back to the beginning. The next trigger will replay all events from the start.

Flush

Called after each batch of events is processed. Useful for flushing buffers or intermediate state:

#[ProjectionFlush]
public function flush(): void
{
    // Called after each batch commit
    // Useful for clearing caches, flushing buffers, etc.
}

See Execution Modes for how batching and flushing work together.

CLI Commands

Initialize a Projection

Symfony

bin/console ecotone:projection:init ticket_list
# Or initialize all projections at once:
bin/console ecotone:projection:init --all

Laravel

Lite

Delete a Projection

Calls #[ProjectionDelete] and removes all tracking state:

Symfony

bin/console ecotone:projection:delete ticket_list

Laravel

Lite

Backfill a Projection

Populates a fresh projection with historical events. See Backfill and Rebuild for details:

Symfony

bin/console ecotone:projection:backfill ticket_list

Laravel

Lite

Rebuild a Projection (Enterprise)

Resets the projection and replays all events. See Backfill and Rebuild for details:

Symfony

bin/console ecotone:projection:rebuild ticket_list

Laravel

Lite

The rebuild command is available as part of Ecotone Enterprise.

Automatic vs Manual Initialization

By default, projections auto-initialize the first time an event triggers them. This means you don't need to run any CLI command — the #[ProjectionInitialization] method is called automatically.

If you need manual control (for example, during blue-green deployments), you can disable auto-initialization:

#[ProjectionV2('ticket_list')]
#[FromAggregateStream(Ticket::class)]
#[ProjectionDeployment(manualKickOff: true)]
class TicketListProjection
{
    // Won't auto-initialize — requires explicit CLI init
}

#[ProjectionDeployment] is available as part of Ecotone Enterprise.

Reset and Trigger

To rebuild a projection manually, you can reset it (clears data and position) and then trigger it (starts processing from the beginning):

1. Reset — calls #[ProjectionReset], clears position to the beginning

2. Trigger — starts processing events from position 0, rebuilding the entire Read Model

This is useful when you've fixed a bug in a handler and need to reprocess all events to correct the data.