Loupe

The “Loupe” filter rule (package filter_loupe, from MM 2.4) creates a full-text index over selected attributes in a dedicated SQLite database and enables powerful full-text search with fuzzy search (similarity search). The implementation is based on the PHP library Loupe.

In contrast to the Levenshtein search, Loupe uses a standalone SQLite database for the index and offers extended configuration options for fuzzy distance and ranking.

See also

Detailed documentation on Loupe: Loupe-based Full-Text Search

Installation

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

composer require metamodels/filter_loupe

Settings when Creating the Filter Rule

Setting	Description
Type	Selection of the filter rule type — here: “Loupe”.
Enabled	Enables or disables this filter rule.
Comment	Free text field for describing the purpose of this filter rule.
Attributes to index	Selection of attributes (checkboxWizard) to be included in the Loupe search index. Required field.
Fuzzy distance	MCW table that defines the allowed Levenshtein distance (fuzzy distance, 0–10) for different word lengths (minimum characters). Default: word length 5 → distance 1; word length 9 → distance 2.
Equalize ranking	If this option is active, all matches are ranked equally regardless of their relevance (no relevance ranking).
Use formatted values	If this option is active, the formatted output values of the attributes are indexed (instead of raw values from the database).

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 search input field.
Hide label at filter widget	Suppresses the output of the label.
Template	Template for the widget output. Default: mm_filteritem_default.
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 “Loupe” filter rule can index the following attribute types:

• Text

• Long text

• Alias

• Combined values

• Token

• Translated text

• Translated long text

Special Functions

Rebuild index

In the filter rule list, an additional operation icon (Loupe icon) appears for Loupe filter rules to manually rebuild the SQLite search index. The index is also automatically updated when indexed items are changed.

SQLite database

The Loupe index is stored in a standalone SQLite file (not in the main Contao database). This enables fast full-text searches even with large amounts of data.