silverstripe-fulltext-filters

This module adds three fulltext SearchFilters to your SilverStripe project.

• FulltextBoolean - similar to the existing Fulltext filter, but uses IN BOOLEAN MODE, and transforms the search phrase to take full advantage of this. See characteristics of Boolean full-text searches here.
• FulltextRelevance - adds relevance to the select query, accepts a 'Weight' argument which is applied to the relevance score, and provides hooks to sort results by the sum of all weighted indexes within the query
• FulltextBooleanRelevance - same as FulltextRelevance but uses the FulltextBoolean filter as its base and basis for matching. Uses the Boolean mode relevance calculation (which can differ from Fulltext in Natural Language Mode)

N.b. - Full-text relevance scores are binary (1 or 0) in Boolean Mode, unless the table engine is InnoDB. By default SilverStripe enforces MyISAM for tables containing a fulltext index. Use fromholdio-silverstripe-fulltext-innodb to overcome this.

Requirements

• silverstripe-framework ^4

Recommended

• fromholdio/silverstripe-fulltext-innodb ^1.0

Installation

composer require fromholdio/silverstripe-fulltext-filters

Details & Usage

In short, use this like any other set of SearchFilters:

// Define your fulltext indexes:
private static $indexes = [
    'TitleFields' => [
        'type' => DBIndexable::TYPE_FULLTEXT,
        'columns' => [
            'Title',
            'MenuTitle'
        ]
    ],
    'ContentFields' => [
        'type' => DBIndexable::TYPE_FULLTEXT,
        'columns' => [
            'Content',
            'MetaDescription'
        ]
    ]
];

// Use in ORM filters:

// We're using BOOLEAN MODE matching
// Matches to the TitleFields index are weighted as five times more significant than ContentFields matches
// We're calculating the sum of relevance scores per matched record, and ordering the results by descending relevance score

public function getResults($value)
{
    $objects = ObjectClass::get()
        ->filterAny([
            'TitleFields:FulltextBooleanRelevance(5)' => $value,
            'ContentFields:FulltextBooleanRelevance' => $value
        ])
        ->sort('@TitleFieldsScore + @ContentFieldsScore DESC');
}

More documentation to come. Look at the source code in the meantime, or submit an issue.

Two key hooks:

• You can access the relevance value the database assigns per index and per record using ->{IndexName}Relevance
• Per the example above, these relevance values are made available within the query for sort but also available for additional where/etc, using variable names @{IndexName}Score

To Do

• Documentation 😅