Single Select

The “Single Select” filter rule (package filter_select) outputs a frontend widget through which visitors can select a single value from a selection list. Items are filtered by the selected value of an attribute. This filter rule is typically combined with the Single Select (select) attribute type to make a 1:n relation filterable in the frontend.

Alternatively, the templates mm_filteritem_radiobutton.html5 (radio buttons) and mm_filteritem_linklist.html5 (link list) are available.

Installation

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

composer require metamodels/filter_select

Settings when Creating the Filter Rule

Setting	Description
Type	Selection of the filter rule type — here: “Single Select”.
Enabled	Enables or disables this filter rule.
Comment	Free text field for describing the purpose of this filter rule.
Attribute	The attribute by whose value items should be filtered.
Label attribute	Optional attribute whose value is used as the display text for the options in the widget (e.g. a name or title attribute).

Settings for the Frontend Widget

Setting	Description
URL parameter	The key of the URL parameter for passing the filter value. Without input, the column name of the attribute is used. With auto_item, only the value — without key — is embedded in the URL.
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.
Use the label as empty option	The label is used as the first empty option (instead of an empty row).
Template	Template for the widget output. Default: mm_filteritem_default; alternatively: mm_filteritem_radiobutton or mm_filteritem_linklist.
Sorting	Sorting of the selection options in the widget (ascending or descending).
Default	Pre-selected value in the frontend widget.
Allow empty selection	Adds an empty option (“All”) to the selection list.
Only assigned values	Shows only values in the widget that are actually assigned in at least one item of the MetaModel.
Only remaining values	Shows only values for which results still exist after applying the other active filters (dynamic filter options).
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 “Single Select” filter rule is particularly suitable for:

• Single Select [select]

• Translated Single Select [select]

• Text

• Alias

• Combined Values

• Token

Special Functions

Radio buttons and link lists

Via the template selection, the widget can be output as a radio button list (mm_filteritem_radiobutton) or as a link list (mm_filteritem_linklist). Link lists are particularly suitable for SEO-optimized navigation without form submission.