Input
An Input is the abstract notion of some information provided to an application by its user. To make this more tangible, inputs could be implemented as any of the following: * the submission of a typical HTML form a user could fill in, * the tap of a button on a mobile device, * the selection of items from a list on a native application, * a voice response providing information via any IVR system, * a thought interpreted by a neural link, * a physical movement interpreted by a motion-detection device, * a retinal scan, * picking items from lists of information by looking and blinking * or any other system by which a human may provide information to a machine
The nature of the implementation for an input is up to the UI Designer. RIDDL's concept of it is based on the net result: the data type received by the application.
An input is a named component of an application that receives data of a specific type from a user of the application. Each input can define data types and declares a command message as the data received by the application's input.
Syntax¶
An input is written as an alias, an identifier, an acquisition verb, and the type it takes in:
form Signup accepts type SignupDetails
button Checkout activates type Boolean
picklist Country selects type CountryCode
Aliases: input, form, text, button, picklist, selector, item
Acquisition verbs: acquires, reads, takes, accepts, admits,
enters, provides, selects, chooses, picks, initiates, submits,
triggers, activates, starts
The verbs selects, chooses, picks, enters and provides were added in
RIDDL 2.0; the rest are unchanged.
Selection verbs expect a choice type
An input using a selection verb — selects, chooses or picks —
whose type is not a choice among options draws a StyleWarning. A
selection widget should take an
Enumeration or Alternation; a String or an
Integer is almost certainly not what was meant.
This is never an Error: a predefined type is treated as resolved-but-not-a- choice, and a genuinely unresolved reference is skipped so the warning does not pile onto the real error.
Reading an Input¶
A handler reads an input's value with the get from value
expression:
on command Register {
let details = get from input Signup
tell command CreateAccount(details) to entity Account
}
Design References¶
An input may carry a figma reference linking it to the frame that depicts it.