silverstripe-fulltextsearch/docs/en/04_advanced_configuration.md

Advanced configuration

Facets

Multiple indexes

Multiple indexes can be created and searched independently, but if you wish to override an existing index with another, you can use the $hide_ancestor config.

use SilverStripe\Assets\File;
use My\Namespace\Index\MyIndex;

class MyReplacementIndex extends MyIndex
{
    private static $hide_ancestor = MyIndex::class;

    public function init()
    {
        parent::init();

        $this->addClass(File::class);
        $this->addFulltextField('Title');
    }
}

You can also filter all indexes globally to a set of pre-defined classes if you wish to prevent any unknown indexes from being automatically included.

SilverStripe\FullTextSearch\Search\FullTextSearch:
  indexes:
    - MyReplacementIndex
    - CoreSearchIndex

Synonyms

Spell check

Boosting/Weighting

Results aren't all created equal. Matches in some fields are more important than others; for example, a page Title might be considered more relevant to the user than terms in the Content field.

To account for this, a "weighting" (or "boosting") factor can be applied to each searched field. The default value is 1.0, anything below that will decrease the relevance, anything above increases it.

To adjust the relative values, pass them in as the third argument to your addSearchTerm() call:

use My\Namespace\Index\MyIndex;
use SilverStripe\FullTextSearch\Search\Queries\SearchQuery;
use Page;

$query = SearchQuery::create()
    ->addSearchTerm(
        'fire',
        null, // don't limit the classes to search
        [
            Page::class . '_Title' => 1.5,
            Page::class . '_Content' => 1.0,
            Page::class . '_SecretParagraph' => 0.1,
        ]
    );
$results = singleton(MyIndex::class)->search($query);

This will ensure that Title is given higher priority for matches than Content, which is well above SecretParagraph.

Indexing related objects

Subsites

Adding new fields