FacetWP Relevanssi Integration Addon

A search box that doesn't find what the visitor types

You have a filtered listing and, even so, some visitors ignore the facets and type exactly what they are looking for. Relevanssi tackles that problem because it keeps its own search index in the database, and this add-on lets FacetWP's search facet use it.

Be clear from the start that it replaces neither of the two plugins: you need FacetWP and Relevanssi (the free version or Relevanssi Premium; Relevanssi Light is not supported). The add-on is only the bridge between them.

Walkthrough with FacetWP Relevanssi Integration Addon: from the default search to a facet with its own index

Step 1, activate the add-on. Relevanssi hooks into WordPress core search, so the integration is not optional: without the add-on, search facets and the site's results page don't work properly.

Step 2, choose the engine in each facet. Once activated, every Search facet shows a new option, "Relevanssi", inside its "Search engine" setting. You have to select it facet by facet: otherwise it won't return results. If for some reason you prefer the "WP Default" engine, the only way is to disable Relevanssi on the page where that facet sits.

Step 3, decide what happens with the /?s= page. If the site's results page has facets, the above is enough. If it has none, it won't show results, and the fix is to disable FacetWP on that page.

Step 4, test. FacetWP asks Relevanssi for the IDs of the posts to show, so if something looks odd, start with Relevanssi's settings. Its "Admin search" feature (in the Dashboard) lets you see the results with the current configuration. And if a particular word returns nothing, check the stopwords list under Settings > Relevanssi > Stopwords: these are words removed from the index that never return anything.

Three questions before setting it up

Does it work with Relevanssi Light?

No. The integration covers free Relevanssi and Relevanssi Premium, but not Light.

Can I leave the facet on WordPress's default engine?

Only by disabling Relevanssi on the page where the facet is. While Relevanssi is active there, the facet must use the "Relevanssi" engine.

My results page has no facets, what do I do?

It won't show results with the add-on active. Disable FacetWP on that page so it works again.

A 500-result cap and a database that grows

For performance reasons, with "Throttle searches" enabled (Settings > Relevanssi > Searching, and it is on by default), Relevanssi returns at most 500 results, and the search facet inherits that limit. You can turn it off, but if your listing template query handles many posts, performance may suffer. You can also lower the cap with a filter on pre_option_relevanssi_throttle_limit in your child theme's functions.php (the default value is 500). Relevanssi recommends not going below 200, because low values make results less relevant, and the filter only works if "Throttle searches" stays enabled.

Another limit is space: Relevanssi can need hundreds of MB. As a reasonable estimate, multiply the size of your wp_posts table by three. On hosting with little room for database tables, or on a site with tens of thousands of posts and tight resources, it can cause problems.

When FacetWP Relevanssi Integration Addon returns zero results because of a hidden shortcode

Relevanssi's "Create custom search result snippets" option builds excerpts from the content of posts. If any of the pages in the results contains a Listing Builder shortcode, or a block, module, widget or element with a FacetWP listing template, those extra queries can interfere and cause an unexpected "no results".

Worse still: if that query retrieves the same page it is on, an infinite loop can occur that may exhaust memory and leave the page, the site or even the server unresponsive. If your results don't show or pages hang, look for that kind of content among the results and exclude it from search in Relevanssi's settings.