Autocomplete functionality can be enabled, disabled or configured through settings in searches.ini. Each search type defined in your basic search type drop-down can be assigned its own custom autocomplete handler. The currently available handlers and configuration details can be found in the comments above the [Autocomplete] and [Autocomplete_Types] sections of searches.ini.

Autocomplete handlers are standard VuFind® plug-ins; more details can be found on the autosuggesters plugin page.

The current default autocomplete handler uses a fairly simple Solr lookup. Here are some more sophisticated approaches which may be worth pursuing:

• The TermsComponent may be an appropriate Solr search handler to get suggestions from. But left hand truncation is still not possible with that.
• On https://lucidworks.com/post/auto-suggest-from-popular-queries-using-edgengrams/ Jay Hill outlines using EdgeNGrams to set up autocomplete against popular queries parsed from the Solr logs.
• A more modern approach worth investigating would be to use Solr's native Suggester component, which did not yet exist when VuFind®'s autocomplete logic was originally implemented.