fieldId
The DOM id of a field's control, for code that has no field at hand.
Builds the DOM id that fieldParts gives the control of a field, for code that has no
field at hand — an error summary above the form that links to each invalid field, for example.
The id is the form's id, a hyphen, and the field's path with every run of dots and brackets
replaced by __. Fields of two different forms therefore never share an id, and the id can be
used in a CSS selector without escaping.
Parameters
| Name | Description |
|---|---|
formId | The id of the form, as TanStack Form reports it in form.formId. |
path | The path of the field, such as email, address.zip or contacts[0].name. |
Returns
The id of the field's control, such as signup-address__zip.
Remarks
The replacement cannot be reversed: a field literally named a__b gets the same id as the
path a.b.
Example
<a href={`#${fieldId(form.formId, 'address.zip')}`}>Postal code</a>