Option

Options are instructions to translators on how a particular definition should be regarded. Any translator can make use of any option. Options can take a list of string arguments much like the options and arguments to a program. If none are specified, the option is considered to be a Boolean value that is true if specified.

Options appear in with { } metadata blocks, not inside a definition's body. The syntax is option is option_name with optional string arguments:

entity Order is {
  ???
} with {
  option is event-sourced
  option is technology("Akka")
}

Every vital definition in RIDDL allows a technology option that takes any number of string arguments. These can specify the technologies intended for the implementation. This idea was adapted from a similar idea in Simon Brown's C4 Model For Software Architecture.

Other options are specific to the kind of vital definition. Non-vital definitions do not allow options.

Known Options By Definition¶

Definition	Supported Options
Adaptor	`css`, `faicon`, `kind`, `technology`
Application	`css`, `faicon`, `kind`, `technology`
Connector	`kind`, `persistent`, `technology`
Context	`css`, `faicon`, `gateway`, `kind`, `namespace`, `package`, `service`, `technology`, `wrapper`
Domain	`css`, `external`, `faicon`, `kind`, `namespace`, `package`, `technology`
Entity	`aggregate`, `available`, `consistent`, `css`, `event-sourced`, `faicon`, `finite-state-machine`, `kind`, `message-queue`, `technology`, `transient`, `value`
Epic	`css`, `faicon`, `kind`, `sync`, `technology`
Projector	`css`, `faicon`, `kind`, `technology`
Repository	`css`, `faicon`, `kind`, `technology`
Saga	`css`, `faicon`, `kind`, `parallel`, `sequential`, `technology`
Streamlet	`css`, `kind`, `technology`

Common Options¶

These options are available on most definitions:

technology — Names the implementation technologies, adapted from Simon Brown's C4 Model. Takes string arguments: option is technology("Kafka")
kind — A semantic categorization of the definition. Takes a string argument: option is kind("device")
css — A CSS class name for visual rendering
faicon — A Font Awesome icon name for visual rendering

Notable Definition-Specific Options¶

Entity: event-sourced, value, aggregate, transient, consistent, available, finite-state-machine, message-queue
Context: gateway, service, wrapper
Domain: external
Connector: persistent
Saga: parallel, sequential
Epic: sync

Occurs In¶

Metadata blocks (with { }) on any vital definition.

Contains¶

Option values which are simple identifiers with an optional set of string arguments.