wool-model

A module to provide class to model Command and Event, the building blocks of Wool project Rule engine, CQRS / Event storage approach.

API Doc

Table of Contents

• Command
  • Parameters
  • Examples
• EventStatus
  • Examples
• Event
  • Parameters
  • isSuccess
  • isInvalid
  • isError
  • stringify
  • toString
  • successFromCommand
  • invalidFromCommand
  • errorFromCommand
  • parse
  • stringify

Command

A class to model Command sent to Wool

Parameters

• t Date a timestamp of the command emission
• o number an order number for command issued at the same time
• name string the name of the required command
• param object the parameters key-value

Examples

const cmd = new Command(new Date(), 0, 'walk', {to: 'library', speed: 'normal'})

EventStatus

An Enum of string, with following valid values :

• S: the event is a success
• I: the event is invalid (not validated by rule conditions)
• E: the event is an error (an unexpected error happened during event treatment)

Type: string

Examples

if (t === EventStatus.succes) {
  ...
}

Event

A class to model Event validated, executed and stored by Wool

Parameters

• t Date a timestamp of the event storage
• o number an order number for events issued at the same time
• name string the name of the command that trigger the event
• data object the data of the event (derived from command parameters)
• status EventStatus the status of the event
• message (string | Error)? for status invalid or error a message detailing the reason of being unsuccessful

isSuccess

Check if event is a EventStatus.succes

Returns boolean

isInvalid

Check if event is EventStatus.invalid

Returns boolean

isError

Check if event is an EventStatus.error

Returns boolean

stringify

A method to make and Event stringify itself

Returns string a stringified Event

toString

A string representation of an Event

Returns string a string representation of an Event

successFromCommand

A static method to create EventStatus.succes Event

Parameters

• cmd Command the original command
• data object the actual data after command execution

Returns Event an event derivative from given Command

invalidFromCommand

A static method to create EventStatus.invalid Event

Parameters

• cmd Command the original command
• message string the explanation message for invalidity of the command

Returns Event an event derivative from given Command

errorFromCommand

A static method to create EventStatus.error Event

Parameters

• cmd Command the original command
• message string the explanation message for error during the command execution

Returns Event an event derivative from given Command

parse

A static method to create Event from stringified Event

Parameters

• s string a stringified Event

Returns Event the event

stringify

A static method to stringify Event

Parameters

• e Event a genuine event

Returns string a stringified Event