Form Autofill Heuristics

Form Autofill Heuristics module is for detecting the field type based on autocomplete attribute, the regular expressions and the customized logic in each parser.

Debugging

The pref extensions.formautofill.heuristics.enabled is “true” in default. Set it to “false” could be useful to verify the result of autocomplete attribute.

Dependent APIs

element.getAutocompleteInfo() provides the parsed result of autocomplete attribute which includes the field name and section information defined in autofill spec

Regular Expressions

This section is about how the regular expression is applied during parsing fields. All regular expressions are in HeuristicsRegexp.sys.mjs.

Parser Implementations

The parsers are for detecting the field type more accurately based on the near context of a field. Each parser uses FieldScanner to traverse the interested fields with the result from the regular expressions and adjust each field type when it matches to a grammar.

_parsePhoneFields
- related type: tel, tel-*
_parseStreetAddressFields
- related type: street-address`, `address-line[1-3]
_parseAddressFields
- related type: address-level[1-2]
_parseCreditCardExpiryFields
- related type: cc-exp, cc-exp-month, cc-exp-year
_parseCreditCardNameFields
- related type: cc-name, given-name, additional-name, family-name
_parseCreditCardNumberFields
- related type: cc-number