DemetriaBehavior
Validation
A step must be valid before forward navigation or completion. Backward navigation never validates the current step.
Required and optional fields
A field is required only when required === true. An
absent flag and required: false are equivalent. Optional
empty values pass validation; optional non-empty values still follow
their type rules.
{ name: 'name', type: 'text', label: 'Name', required: true }
{ name: 'email', type: 'email', label: 'Email' } // optional
Whitespace detail: v0.1.1 considers only
'', null, and
undefined empty. A whitespace-only text value therefore
passes required validation.
Rules by field type
| Type | Empty | Non-empty rule |
|---|---|---|
| text / textarea | Passes unless required | Must be a string |
| Passes unless required | Must match the built-in basic email pattern | |
| number | Passes unless required | Must be a finite JavaScript number; numeric strings fail |
| select | Passes unless required | Must equal one declared option value |
| checkbox | false passes only when optional |
Must be boolean; required means it must be true
|
Try validation
Submit empty, then enter an invalid optional email. This form runs the compiled Demetria package code.
Complete the form to inspect its values.
Current limits
Validation messages are built in and English-only. v0.1.1 has no custom validators, asynchronous validation, cross-field rules, or server-error API. Validate again on the server for every submission; browser validation is a usability feature, not a security boundary.