Dirty Tracking & Reset

Dirty tracking

dirty lives on FieldApi, so any field in the form tree can report whether its value differs from its slice of the baseline:

form.dirty;

form.field("address").dirty;

form.field("address").field("line1").dirty;

It's a deep-equality check against the baseline. An edit undone (e.g. typed, then typed back) makes dirty false again. A group's dirty needs no separate aggregation: its value already unions every descendant's, so one check against its baseline slice covers everything underneath.

The baseline is set once, at construction, and only moves via reset()/resetField() — not on every render, even with a fresh initialValue object each time (as a re-rendering React hook would pass). This keeps it stable no matter how often updateOptions runs underneath.

Resetting the whole form

// Discard edits, back to the original initial value.
form.reset();

// Resets the form to a new baseline after a successful submission.
const saved = await save(form.value);
form.reset(saved);

reset(value) restores value (defaulting to the current baseline) and clears touched throughout the tree. The value cascades to every registered field, so validation re-runs against it instead of leaving stale errors. Passing an explicit value also moves the dirty baseline to it.

Resetting a single field

resetField, on FormApi, is the same idea scoped to one field:

// Discard edits to just this one field.
form.resetField("email");

// After successfully saving just this field.
const saved = await saveEmail(form.field("email").value);
form.resetField("email", saved);

It moves that field's slice of the baseline (defaulting to its current value, a no-op) the same way reset does for the whole tree — siblings and the rest of the baseline stay untouched. If the field is currently registered (mounted), resetField also restores its value and clears its touched. If not, only the baseline moves — it never registers a field just to reset it, so a conditionally-rendered field you haven't mounted yet stays unregistered but starts clean whenever it does.

What's next

• FormApi — full reference on JSR