Question types overview

Forms-Engine ships twelve question types. Each owns four things: what it renders in the embed, its configuration options in the editor, the shape its answer is stored in, and the rule operators conditions may use against it.

Type	Renders	Stored answer	Rule operators
Text box	single/multi-line text input	string	equals, not equals
Radio	radio group	string (option label)	equals, not equals
Checkboxes	checkbox group	array of option labels	contains, does not contain
Dropdown	searchable select	string (option label)	equals, not equals
Date	text input + popup calendar	`"YYYY-MM-DD"` string	equals, not equals, before, after
Number	numeric input, optional %/currency adornment	JSON number	equals, not equals, greater than, less than
Email	email input	string	equals, not equals
Phone	phone input	string	equals, not equals
Toggle	two-button yes/no control	boolean	equals, not equals
Address	multi-field address with geocoding autocomplete	flat object of sub-fields	equals, not equals (per sub-field)
File upload	drag-and-drop dropzone	array of file references	—
Display text	sanitized rich text, no input	— (never stored)	—

Three cross-cutting facts worth knowing before the per-type pages:

Answers are typed. 0 is a real number answer and false a real toggle answer — “answered” never means “truthy”. An empty text box or an empty checkbox selection stores nothing at all (the key is removed, never an empty string or empty array).
Choice answers store the option label, so responses read naturally in Mongo and CSV without a lookup table. Option ids exist in the definition for future-proofing, not in the stored data.
Unknown types degrade gracefully. A definition containing a type the embed doesn’t know (e.g. from a newer server) renders a neutral placeholder, never blocks navigation, and reports itself via fe-error — old embeds don’t break when new types ship.

Question types are also the extension point: adding one requires only new registry modules (core semantics, renderer template, editor panel, backend validator) with zero changes to navigation, persistence, or the rule engine. The worked example lives in the repo at docs/adding-a-question-type.md.