Register

The “Register” filter rule (package filter_register) filters items by the first letter of an attribute value. It generates a list of all existing or possible initial letters as a clickable navigation (A–Z) through which visitors can restrict the output to items starting with a specific letter.

Typical use cases: alphabetical navigation in business directories, person lists, glossaries, or other alphabetically sorted outputs.

The included template mm_filteritem_register.html5 is intended for the register-specific output.

Installation

The filter rule is installed via the Contao Manager or Composer:

composer require metamodels/filter_register

Settings when Creating the Filter Rule

Setting	Description
Type	Selection of the filter rule type — here: “Register”.
Enabled	Enables or disables this filter rule.
Comment	Free text field for describing the purpose of this filter rule.
Attribute	The text attribute by whose first letter items should be filtered (e.g. last name, company name).

Settings for the Frontend Widget

Setting	Description
URL parameter	The key of the URL parameter for the selected letter.
URL type for the parameter	Defines whether the parameter is passed as a slug (friendly URL) or as a GET parameter (from MM 2.4) — see SEO
Label	Label of the filter widget.
Hide label at filter widget	Suppresses the output of the label.
Template	Template for the widget output. Default: `mm_filteritem_register`.
Show count	Shows the number of items for each letter.
Hide empty letters	Hides letters for which no items exist.
Allow multiple filtering	Allows simultaneous filtering by multiple initial letters.
Only remaining values	Shows only letters for which results still exist after applying the other active filters.
Ignore this filter for remaining values	This filter does not return its own options as a restriction when calculating remaining values.
CSS ID/class	Sets a CSS ID or class on the widget element.

Matching Attributes

The “Register” filter rule is suitable for attributes with text values:

Special Functions

Template mm_filteritem_register

The included template renders the letter list with links. The template can be customized using the standard Contao method (template inheritance) to integrate a different layout or special characters.