Textregex profilefield plugin allows to have a short text input field with regex validation. Enabling to ensure a valid format of the field data.
A Perl-compatible regular expression is used to validate the user input. Regex can be defined during the creation of the profile field itself. Because the regex definition might be challenging, we recommend using this plugin only if you can restrict the new field definitions to expert users. The plugin performs a regex validation on the server side when saving the field. Please add a detailed description for the field that explains the rules in a human-readable form, as most of the users will not understand the regex and, therefore, will be unable to correct their input unless you have a good description. For multi-language sites, currently, the only way to provide a translated description is to use a multilang filter on the site and provide a description in all used languages in the description field.
Once the field is defined, users can use it like a normal text field. Enter data and store it. If the entered value does not match the regex, input will not be accepted, and the user will receive a standard notification, including the regex. Field data validation is performed on both the server and client sides.
This plugin cannot be used as a custom field, e.g. for course custom fields. If you want to add regex validated fields to a course, please use https://github.com/benyovszky/moodle-customfield_textregex plugin instead.