Tutorial: Indexables

Indexables

In ElasticPress 3.0, we’ve introduced the concept of Indexables. In the past, ElasticPress integrated with WordPress’ WP_Query API, which enabled redirection of WP_Query queries through Elasticsearch instead of MySQL. Indexables takes this a step further, enabling indexing, search, and queries on any queryable object in WordPress.

As of 3.0, ElasticPress ships with the following built-in Indexables: Posts, Terms, and Users. The Posts Indexable roughly corresponds to the previous WP_Query integration, and the Users Indexable adds support for WP_User_Query in ElasticPress. The Terms Indexable adds support for WP_Term_Query. Future versions of ElasticPress will include additional WordPress APIs (such as WP_Comment_Query), and you can also create your own custom Indexables by extending the Indexable class.

Post Indexable

ElasticPress integrates with WP_Query if the ep_integrate parameter is passed (see below) to the query object. If the search feature is activated (which it is by default), all queries with the s parameter will be integrated with as well. ElasticPress converts WP_Query arguments to Elasticsearch readable queries. Supported WP_Query parameters are listed and explained below. ElasticPress also adds some extra WP_Query arguments for extra functionality.

Supported WP_Query Parameters

  • ep_integrate (bool)

    Allows you to run queries through Elasticsearch instead of MySQL. This parameter is the meat of the plugin. For example:

    Get 20 of the latest posts

    new WP_Query( array(
        'ep_integrate'   => true,
        'post_type'      => 'post',
        'posts_per_page' => 20,
    ) );
    

    Get all posts with a specific category slug

    new WP_Query( array(
        'ep_integrate'   => true,
        'post_type'      => 'post',
        'posts_per_page' => -1,
        'tax_query' => array(
            array(
                'taxonomy' => 'category',
                'terms'    => array( 'term-slug' ),
                'field'    => 'slug',
            ),
        ),
    ) );
    

    Setting ep_integrate to false will override the s parameter if provided.

  • s (string)

    Search keyword. By default used to search against post_title, post_content, and post_excerpt. (Requires search feature)

  • posts_per_page (int)

    Number of posts to show per page. Use -1 to show all posts (the offset parameter is ignored with a -1 value). Set the paged parameter to paginate based on posts_per_page.

  • tax_query (array)

    Filter posts by terms in taxonomies. Takes an array of form:

    new WP_Query( array(
        's'         => 'search phrase',
        'tax_query' => array(
            array(
                'taxonomy' => 'taxonomy-name',
                'field'    => 'slug',
                'terms'    => array( 'term-slug-1', 'term-slug-2', ... ),
            ),
        ),
    ) );
    

    tax_query accepts an array of arrays where each inner array only supports taxonomy (string), field (string), operator (string), and terms (string|array) parameters. field must be set to slug, name, or term_id. The default value for field is term_id. terms must be a string or an array of term slug(s), name(s), or id(s). operator defaults to in and also supports not in and and.

    The outer array supports the relation parameter. Acceptable values are and and or. The default is and.

  • The following shorthand parameters can be used for querying posts by specific dates:

    • year (int) - 4 digit year (e.g. 2011).
    • month or monthnum (int) - Month number (from 1 to 12).
    • week (int) - Week of the year (from 0 to 53).
    • day (int) - Day of the month (from 1 to 31).
    • dayofyear (int) - Day of the month (from 1 to 365 or 366 for leap year).
    • hour (int) - Hour (from 0 to 23).
    • minute (int) - Minute (from 0 to 59).
    • second (int) - Second (0 to 59).
    • dayofweek (int|array) - Weekday number, when week starts at Sunday (1 to 7).
    • dayofweek_iso (int|array) - Weekday number, when week starts at Monday (1 to 7).

    This is a simple example which will return posts which are created on January 1st of 2012 from all sites:

    new WP_Query( array(
        's' => 'search phrase',
        'sites' => 'all',
        'year'  => 2012,
        'monthnum' => 1,
        'day'   => 1,
    ) );
    
  • date_query (array)

    date_query accepts an array of keys and values (array|string|int) to find posts created on specific dates/times as well as an array of arrays with keys and values (array|string|int|boolean) containing the following parameters after, before, inclusive, compare, column, and relation. column is used to query specific columns from the wp_posts table. This will return posts which are created after January 1st 2012 and January 3rd 2012 8AM GMT:

    new WP_Query( array(
        's' => 'search phrase',
        'date_query' => array(
            array(
                'column' => 'post_date',
                'after' => 'January 1st 2012',
            ),
            array(
                'column' => 'post_date_gmt',
                'after'  => 'January 3rd 2012 8AM',
            ),
        ),
    ) );
    

    Currently only the AND value is supported for the relation parameter.

    inclusive is used on after/before options to determine whether exact value should be matched or not. If inclusive is used and you pass in sting without specific time, it will be converted to 00:00:00 on that date. In this case, even if inclusive was set to true, the date would not be included in the query. If you want to include that specific date, you need to pass the time as well. (e.g. 'before' => '2012-01-03 23:59:59')

    The example will return all posts which are created on January 5th 2012 after 10:00PM and 11:00PM inclusively, because the time is specified:

    new WP_Query( array(
        's' => 'search phrase',
        'date_query' => array(
            array(
                'column' => 'post_date',
                'before' => 'January 5th 2012 11:00PM',
            ),
            array(
                'column' => 'post_date',
                'after'  => 'January 5th 2012 10:00PM',
            ),
            'inclusive' => true,
        ),
    ) );
    

    compare supports the following options:

    • = - Posts will be returned that are created on a specified date.
    • != - Posts will be returned that are not created on a specified date.
    • > - Posts will be returned that are created after a specified date.
    • >= - Posts will be returned that are created on a specified date or after.
    • < - Posts will be returned that are created before a specified date.
    • <= - Posts will be returned that are created on a specified date or before that.
    • BETWEEN - Posts will be returned that are created between a specified range.
    • NOT BETWEEN - Posts will be returned that are created not in a specified range.
    • IN - Posts will be returned that are created on any of the specified dates.
    • NOT IN - Posts will be returned that are not created on any of the specified dates.

    compare can be combined with shorthand parameters as well as with after and before. This example will return all posts which are created during Monday to Friday, between 9AM to 5PM:

    new WP_Query( array(
        's' => 'search phrase',
        'date_query' => array(
            array(
                'hour'      => 9,
                'compare'   => '>=',
            ),
            array(
                'hour'      => 17,
                'compare'   => '<=',
            ),
            array(
                'dayofweek' => array( 2, 6 ),
                'compare'   => 'BETWEEN',
            ),
        ),
    ) );
    
  • meta_query (array)

    Filter posts by post meta conditions. Meta arrays and objects are serialized due to limitations of Elasticsearch. Takes an array of form:

    new WP_Query( array(
        's'          => 'search phrase',
        'meta_query' => array(
            array(
                'key'   => 'key_name',
                'value' => 'meta value',
                'compare' => '=',
            ),
        ),
    ) );
    

    meta_query accepts an array of arrays where each inner array only supports key (string), type (string), value (string|array|int), and compare (string) parameters. compare supports the following:

    • = - Posts will be returned that have a post meta key corresponding to key and a value that equals the value passed to value.
    • != - Posts will be returned that have a post meta key corresponding to key and a value that does NOT equal the value passed to value.
    • > - Posts will be returned that have a post meta key corresponding to key and a value that is greater than the value passed to value.
    • >= - Posts will be returned that have a post meta key corresponding to key and a value that is greater than or equal to the value passed to value.
    • < - Posts will be returned that have a post meta key corresponding to key and a value that is less than the value passed to value.
    • <= - Posts will be returned that have a post meta key corresponding to key and a value that is less than or equal to the value passed to value.
    • EXISTS - Posts will be returned that have a post meta key corresponding to key.
    • NOT EXISTS - Posts will be returned that do not have a post meta key corresponding to key.
    • BETWEEN - Must pass an array to value such that the array[0] is the lower bound and array[1] is the upper bound. Posts will be returned that have a post meta key corresponding to key and a value that is greater than array[0] and less than array[1].
    • NOT BETWEEN - Must pass an array to value such that the array[0] is the lower bound and array[1] is the upper bound. Posts will be returned that have a post meta key corresponding to key and a value that is greater than array[0] and less than array[1].

    The outer array also supports a relation (string) parameter. By default relation is set to AND:

    new WP_Query( array(
        's'          => 'search phrase',
        'meta_query' => array(
            array(
                'key'   => 'key_name',
                'value' => 'meta value',
                'compare' => '=',
            ),
            array(
                'key'   => 'key_name2',
                'value' => 'meta value',
                'compare' => '!=',
            ),
            'relation' => 'AND',
        ),
    ) );
    

    Possible values for relation are OR and AND. If relation is set to AND, all inner queries must be true for a post to be returned. If relation is set to OR, only one of the inner meta queries must be true for the post to be returned.

    type supports the following values: 'NUMERIC', 'BINARY', 'CHAR', 'DATE', 'DATETIME', 'DECIMAL', 'SIGNED', 'TIME', and 'UNSIGNED'. By default WordPress casts meta values to these types in MySQL so some of these don't make sense in the context of Elasticsearch. ElasticPress does no "runtime" casting but instead compares the value to a different type compiled during indexing

    • NUMERIC - Compares query value to integer version of stored meta value.
    • SIGNED - Compares query value to integer version of stored meta value.
    • UNSIGNED - Compares query value to integer version of stored meta value.
    • BINARY - Compares query value to raw, unanalyzed version of stored meta value. For actual attachment searches, check out this.
    • CHAR - Compares query value to raw, unanalyzed version of stored meta value.
    • DECIMAL - Compares query value to float version of stored meta value.
    • DATE - Compares query value to date version of stored meta value. Query value must be formatted like 2015-11-14
    • DATETIME - Compares query value to date/time version of stored meta value. Query value must be formatted like 2012-01-02 05:00:00 or yyyy:mm:dd hh:mm:ss.
    • TIME - Compares query value to time version of stored meta value. Query value must be formatted like 17:00:00 or hh:mm:ss.

    If no type is specified, ElasticPress will just deduce the type from the comparator used. type is very rarely needed to be used.

  • meta_key (string)

    Allows you to query meta with the defined key. Requires meta_value or meta_value_num be used as well.

  • meta_value (string)

    This value will be queried against the key defined in meta_key.

  • meta_value_num (string)

    This value will be queried against the key defined in meta_key.

  • post_type (string/array)

    Filter posts by post type. any will search all public post types. WP_Query defaults to either post or any if no post_type is provided depending on the context of the query. This is confusing. ElasticPress will ALWAYS default to any if no post_type is provided. If you want to search for post posts, you MUST specify post as the post_type.

  • post__in (array)

    Specify post IDs to retrieve.

  • post__not_in (array)

    Specify post IDs to exclude.

  • offset (int)

    Number of posts to skip in ascending order.

  • paged (int)

    Page number of posts to be used with posts_per_page.

  • author (int)

    Show posts associated with certain author ID.

  • author_name (string)

    Show posts associated with certain author. Uses post_author.display_name.

  • orderby (string)

    Order results by field name instead of relevance. Supports: title, modified, meta_value, meta_value_num, type, name, date, and relevance; anything else will be interpretted as a document path i.e. meta.my_key.long or meta.my_key.raw. You can sort by multiple fields as well i.e. title meta.my_key.raw

  • order (string)

    Which direction to order results in. Accepts ASC and DESC. Default is DESC.

  • post_parent (int)

    Show posts that have the specified post parent.

The following are special parameters that are only supported by ElasticPress.

  • search_fields (array)

    If not specified, defaults to array( 'post_title', 'post_excerpt', 'post_content' ).

    • post_title (string)

      Applies current search to post titles.

    • post_content (string)

      Applies current search to post content.

    • post_excerpt (string)

      Applies current search to post excerpts.

    • taxonomies (string => array/string)

      Applies the current search to terms within a taxonomy or taxonomies. The following will fuzzy search across post_title, post_excerpt, post_content, and terms within taxonomies category and post_tag:

      new WP_Query( array(
          's'             => 'term search phrase',
          'search_fields' => array(
              'post_title',
              'post_content',
              'post_excerpt',
              'taxonomies' => array( 'category', 'post_tag' ),
          ),
      ) );
      
    • meta (string => array/string)

      Applies the current search to post meta. The following will fuzzy search across post_title, post_excerpt, post_content, and post meta keys meta_key_1 and meta_key_2:

      new WP_Query( array(
          's'             => 'meta search phrase',
          'search_fields' => array(
              'post_title',
              'post_content',
              'post_excerpt',
              'meta' => array( 'meta_key_1', 'meta_key_2' ),
          ),
      ) );
      
    • author_name (string)

      Applies the current search to author login names. The following will fuzzy search across post_title, post_excerpt, post_content and author user_login:

      new WP_Query( array(
          's'             => 'username',
          'search_fields' => array(
              'post_title',
              'post_content',
              'post_excerpt',
              'author_name',
          ),
      ) );
      
  • aggs (array)

    Add aggregation results to your search result. For example:

    new WP_Query( array(
        's'    => 'search phrase',
        'aggs' => array(
            'name'       => 'name-of-aggregation', // (can be whatever you'd like)
            'use-filter' => true // (*bool*) used if you'd like to apply the other filters (i.e. post type, tax_query, author), to the aggregation
            'aggs'       => array(
                'name'  => 'name-of-sub-aggregation',
                'terms' => array(
                    'field' => 'terms.name-of-taxonomy.name-of-term',
                ),
            ),
        ),
    ) );
    
  • cache_results (boolean)

    This is a built-in WordPress parameter that caches retrieved posts for later use. It also forces meta and terms to be pulled and cached for each cached post. It is extremely important to understand when you use this parameter with ElasticPress that terms and meta will be pulled from MySQL not Elasticsearch during caching. For this reason, cache_results defaults to false.

  • sites (int/string/array)

    This parameter only applies in a multi-site environment. It lets you search for posts on specific sites or across the network.

    By default, sites defaults to current which searches the current site on the network:

    new WP_Query( array(
        's'     => 'search phrase',
        'sites' => 'current',
    ) );
    

    You can search on all sites across the network:

    new WP_Query( array(
        's'     => 'search phrase',
        'sites' => 'all',
    ) );
    

    You can also specify specific sites by id on the network:

    new WP_Query( array(
        's'     => 'search phrase',
        'sites' => 3,
    ) );
    

    You can even specify a group of specific sites on the network:

    new WP_Query( array(
        's'     => 'search phrase',
        'sites' => array( 2, 3 ),
    ) );
    

    Note: Nesting cross-site WP_Query loops can result in unexpected behavior.

User Indexable

The User Indexable is only enabled if the User feature is activated. ElasticPress integrates with WP_User_Query if the ep_integrate or s ( search) parameter passed (see below) to the query object. ElasticPress converts WP_User_Query arguments to Elasticsearch readable queries. Supported WP_User_Query parameters are listed and explained below.

Supported WP_User_Query Parameters

  • number (int)

    The maximum returned number of results.

  • blog_id (int)

    The blog id on a multisite environment. Defaults to the current blog id.

  • role (string|array)

    An array or a comma-separated list of role names that users must match to be included in results. Note that this is an inclusive list: users must match each role. Default empty.

  • meta_key (string)

    Allows you to query meta with the defined key. Requires meta_value or meta_value_num be used as well.

  • meta_value (string)

    This value will be queried against the key defined in meta_key.

  • meta_compare (string)

    Operator to test the 'meta_value'. Possible values are '=', '!=', '>', '>=', '<', '<=', 'LIKE', 'NOT LIKE', 'IN', 'NOT IN', 'BETWEEN', 'NOT BETWEEN', 'EXISTS', and 'NOT EXISTS' ; 'REGEXP', 'NOT REGEXP' and 'RLIKE' were added in WordPress 3.7. Default value is '='.

  • meta_query (array)

    Filter users by user meta conditions. Meta arrays and objects are serialized due to limitations of Elasticsearch. Takes an array of form:

    new WP_User_Query( array(
        's'          => 'search phrase',
        'meta_query' => array(
            array(
                'key'   => 'key_name',
                'value' => 'meta value',
                'compare' => '=',
            ),
        ),
    ) );
    
  • fields (string|array)

    Which fields to return. Defaults to all.

  • nicename (string|array)

    Filter users by user_nicename field.

  • nicename__not_in (string|array)

    Filter users to remove those who match on the user_nicename field.

  • nicename__in (string|array)

    Filter users to include only those who match on the user_nicename field.

  • login

    Filter users by user_login field.

  • login__in

    Filter users to remove those who match on the user_login field.

  • login__not_in

    Filter users to include only those who match on the user_login field.

  • offset (int)

    Offset the returned results (needed in pagination).

  • include (array)

    List of user IDs to be included.

  • exclude

    List of user IDs to be excluded.

  • search

    Searches for possible string matches on columns. NB: Use of the * wildcard before and/or after the string is not currently supported in ElasticPress.

  • search_fields

    Specify fields to be searched.

  • search_columns

    Specify columns in the user database table to be searched. NB: this is merged into search_fields before being sent to Elasticsearch with search_fields overwriting search_columns.