Levenshtein-based Search

The “Levenshtein-based Search” filter rule (package attribute_levenshtein) creates a full-text index over selected attributes and enables a similarity-based full-text search with autocomplete. The search is based on the Levenshtein distance algorithm, which also finds typos and similar-sounding terms.

A prerequisite is the installation of the Levenshtein attribute, which builds the search index in its own table. The included template mm_filteritem_levenshtein.html5 contains the necessary JavaScript logic for autocomplete.

See also

Detailed documentation on the Levenshtein attribute: Levenshtein

Installation

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

composer require metamodels/attribute_levenshtein

Settings when Creating the Filter Rule

Setting	Description
Type	Selection of the filter rule type — here: “Levenshtein-based Search”.
Enabled	Enables or disables this filter rule.
Comment	Free text field for describing the purpose of this filter rule.
Attribute	The Levenshtein attribute that provides the search index.

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_levenshtein (contains JavaScript for autocomplete).
Placeholder	Placeholder text in the search input field.
CSS ID/class	Sets a CSS ID or class on the widget element.
Enable autocomplete	Enables the JavaScript-based autocomplete while typing. Default: active.
Minimum characters for autocomplete	Number of characters at which autocomplete is triggered. Default: 3.
Auto-submit	The search form is automatically submitted when an autocomplete suggestion is selected.

Matching Attributes

The “Levenshtein-based Search” filter rule works exclusively with the special Levenshtein attribute:

• Levenshtein

The Levenshtein attribute can in turn index multiple other attributes (text, long text, alias, etc.).