Raxol.Architecture.EventSourcing.Event (Raxol v2.0.1)

Event structure for event sourcing implementation in Raxol.

Events represent facts about what has happened in the system. They are immutable and form the single source of truth for all state changes.

Event Design Principles

Past Tense: Events represent things that have already happened
Immutable: Once created, events cannot be changed
Rich Information: Events should contain all relevant data
Causality: Events should track what caused them
Versioned: Events should support schema evolution

Usage

defmodule TerminalCreatedEvent do
  use Raxol.Architecture.EventSourcing.Event

  defstruct [
    :terminal_id,
    :user_id,
    :width,
    :height,
    :created_at,
    :metadata
  ]

  @type t :: %__MODULE__{
    terminal_id: String.t(),
    user_id: String.t(),
    width: pos_integer(),
    height: pos_integer(),
    created_at: integer(),
    metadata: map()
  }
end

Summary

Types

event_data()

event_metadata()

t()

Functions

correlate_events(parent_event, child_event)

Creates event correlation chain.

correlated?(event1, event2)

Checks if events are correlated.

create_envelope(event_data, stream_name, opts \\ [])

Creates an event envelope with all required metadata.

event_type?(arg1, expected_type)

Checks if an event is of a specific type.

extract_data(event)

Extracts the event data from an envelope.

from_json(json)

Deserializes an event from JSON.

from_map(map)

Creates an event from a map.

get_causation_id(event)

Gets the causation ID from an event.

get_correlation_chain(events, correlation_id)

Gets all events in a correlation chain.

get_correlation_id(event)

Gets the correlation ID from an event.

get_event_type(arg1)

Gets the event type from an envelope or event data.

is_event_type?(event, expected_type) deprecated

migrate_event(event, migration_fn)

Creates an event migration for schema evolution.

to_json(event)

Serializes an event to JSON.

to_map(event)

Converts an event to a map for storage.

validate_envelope(event)

Validates event envelope structure.