Variable Reference

How the variable namespaces fit together — from registry defaults, through theme overrides, to the values a form renders at runtime. For the values themselves see Runtime Variables; for the helper functions see Code Helpers.

Namespaces

Namespace	Source	Writable	Persistence
$.self.*	Auth session (user profile)	No	Backend-managed
$.form.*	Current form metadata	No	Loaded form record
$.state.*	$state() in scripts	Yes — scripts only	In-memory only (cleared on refresh)
$.variable.*	Registry + active theme override	No	Backend (registry + theme.custom/custom_dark)
$.image.*	Image-type registry variables	No	Backend (registry + theme.images/images_dark)
$.fn.*()	Script-type registry variables	Callable	Backend registry only

Compatibility matrix

Which namespaces resolve in which context. $.fn() entries marked ⚠ are allowed but read-only — the function returns a value and the caller decides whether to $set or $state it.

Context	$.self	$.form	$.state	$.variable	$.image	{{ expr }}	$.fn()
Field default values	✓	✓	✓	✓	✓	—	—
Field labels / placeholders	✓	✓	✓	✓	✓	—	—
Option labels	✓	✓	✓	✓	✓	—	—
Text Display header / body	✓	✓	✓	✓	✓	✓	⚠
On Load / onChange scripts	✓	✓	✓	✓	✓	—	⚠
Button action scripts	✓	✓	✓	✓	✓	—	⚠
Visibility scripts	✓	✓	✓	✓	✓	—	⚠
Visual visibility rules (compare)	✓	✓	✓	✓	✓	—	—
Visual validation rules (compare)	✓	✓	✓	—	—	—	—

Runtime caveats

• $.path is for direct value lookup. {{ }} is required for helper calls or computation. Do not use a bare $get() in text.
• Inside {{ }}: $.self, $.form, $.state, $.variable, $.image, $.fn, $get, $sum, $option, Math, etc. are available. {{ }} expressions are read-only.
• {{ }} expressions are read-only — no $set, $state writes, or $grid. Use On Load scripts for write operations.
• {{ }} expressions only work in Text Display header and body — not in field labels, defaults, or option labels.
• $.form is form metadata. $.state is in-memory only and cleared on page refresh. Use $.variable for persistent values.
• $.fn registry functions are read-only in every caller context. Return a value and let the caller decide whether to $set or $state it.
• $.fn functions with no return are treated as void. Use the usage hints fn:returnable or fn:void to make intent visible in the registry UI.
• Text-type variables only resolve $.variable.* tokens at registry level. $.self, $.form, and $.state resolve later, at form render time.
• Theme runtime can resolve custom/custom_dark for data variables. The Data Variables override tab manages the default/light bucket; dark-specific values still resolve when present on the active theme.
• $.image variables support light/dark overrides via theme.images and theme.images_dark. Registry defaults apply when no theme override exists.

Data-variable types

Registry data variables are typed. The type controls how the stored value is parsed and which namespace exposes it.

Type	Namespace	Parsed to	Use case
string	$.variable	string	Config values, display text
number	$.variable	number (if finite)	Thresholds, counts, rates
boolean	$.variable	true / false	Feature flags
date	$.variable	ISO string	Reference dates
json	$.variable	object / array	Structured config
list	$.variable	string[]	Dropdown options, lookups
text	$.variable	resolved string	Composable text with $.variable.* tokens
script	$.fn	callable function	Registry-owned reusable logic
image	$.image	string (URL)	Theme-overridable image assets

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See also: Scripts overview · Runtime Variables · Examples