Indices Settings

Introduction

Algolia allows you to configure your indices to improve the relevancy of your search results.

Each index comes with its own customizable settings and a complete list of the settings parameters can be found here.

This plugin automatically configures each index with some sensible default settings, that being said, you can of course customize the settings by using some filters.

Settings Anatomy

Before telling you about the default settings per content type and how to customize them, let's have a quick overview of a few parameters.

attributesToIndex: Refers to the attributes that the search will be based on. By default we will generally list here all the text attributes that the user would like to search in. Unless we wrap our attribute name in unordered(), word match position matters, meaning that if a word is found earlier in the indexed attribute, it will be considered a better match.

customRanking Internally, the Algolia Search engine uses a Tie breaking algorithm, which means that at every step of the search process, it will keep only the most relevant results by applying consequently every available ranking algorithm. There are a lot of ranking strategies provided out of the box, like typo, geo, etc. If the search engine has more results to offer than expected, we consider as best practice to provide the engine with some custom metrics to take the best decisions. In this plugin we provide some sensible defaults so that your search results are as accurate as possible. Feel free to add your custom business metrics.

attributesForDistinct For the post content type we actually store multiple records for the same item. Why we do that is explained in the index schema. Even though we have multiple records for a unique post, we only want to display one post as part of the result. For this we use the Algolia attributeForDistinct & distinct feature which is kind of similar to the SQL DISTINCT feature. By using this feature, the search engine will only return the most relevant record for a given query.

attributesForFaceting Algolia allows to prepare your records for faceting. Faceting is the feature allowing you for example to list all posts of a category. Even though we do not yet provide out of the box usage of faceting in the plugin, we tried to already push some sensible default values for the attributesForFaceting.

Searchable Posts Index Settings

Default searchable posts settings:

<?php
$settings = array(
    'attributesToIndex' => array(
        'unordered(post_title)',
        'unordered(content)',
    ),
    'customRanking' => array(
        'desc(is_sticky)',
        'desc(post_date)',
    ),
    'attributeForDistinct'  => 'post_id',
    'distinct'              => true,
    'attributesForFaceting' => array(
        'taxonomy_post_tag',
        'taxonomy_category',
        'post_author.display_name',
        'post_type_label',
    ),
    'attributesToSnippet' => array(
        'post_title:30',
        'content:30',
    ),
    'snippetEllipsisText' => '…',
);

Posts Index Settings

Default posts settings:

<?php
$settings = array(
    'attributesToIndex' => array(
        'unordered(post_title)',
        'unordered(content)',
    ),
    'customRanking' => array(
        'desc(is_sticky)',
        'desc(post_date)',
    ),
    'attributeForDistinct'  => 'post_id',
    'distinct'              => true,
    'attributesForFaceting' => array(
        'taxonomy_post_tag',
        'taxonomy_category',
        'post_author.display_name',
    ),
    'attributesToSnippet' => array(
        'post_title:30',
        'content:30',
    ),
    'snippetEllipsisText' => '…',
);

Terms Index Settings

Default terms settings:

<?php
$settings = array(
    'attributesToIndex' => array(
        'unordered(name)',
        'unordered(description)',
    ),
    'customRanking' => array(
        'desc(posts_count)',
    ),
);

Users Index Settings

Default users settings:

<?php
$settings = array(
    'attributesToIndex' => array(
        'unordered(display_name)',
    ),
    'customRanking' => array(
        'desc(posts_count)',
    ),
);

Custom Index Settings

You can customize the settings pushed to Algolia for every content type. To do so simply use the available filters:

Custom Index Settings Example

Let's say you have some custom metric named visits_count and you would like to add a custom ranking rule on that one:

<?php

function custom_posts_index_settings( array $settings ) {
    $custom_ranking = $settings['customRanking'];
    array_unshift( $custom_ranking, 'desc(visits_count)' );
    $settings['customRanking'] = $custom_ranking;

    return $settings;
}
add_filter( 'algolia_posts_index_settings', 'custom_posts_index_settings' );

Every post type having it's own index in Algolia, we can also determine custom settings per post type like:

<?php

// Customize settings for pages only.
function custom_pages_index_settings( array $settings ) {
    /* Your adjustments */

    return $settings;
}
add_filter( 'algolia_posts_page_index_settings', 'custom_pages_index_settings' );

// OR customize for posts only.
function custom_posts_index_settings( array $settings ) {
    /* Your adjustments */

    return $settings;
}
add_filter( 'algolia_posts_post_index_settings', 'custom_posts_index_settings' );

Register custom facet

Let's say you want to register a custom attribute as a facet number_bedroom in Algolia:

<?php

function custom_posts_index_settings( array $settings ) {
    $settings['attributesForFaceting'][] = 'number_bedroom';

    return $settings;
}
add_filter( 'algolia_posts_index_settings', 'custom_posts_index_settings' );