elgg_solr

Speed up site search by using a dedicated Solr search index

• Search Entities
• Search tags (exact match)
• Search File contents

This plugin follows the structure of the default Elgg search plugin, can be extended using the same search plugin hooks.

Dependencies

• This plugin depends on the default elgg search plugin (bundled with Elgg)
• This plugin depends on the vroom plugin - https://github.com/jumbojett/vroom

Installation

1. Download the plugin and upload it to /mod/elgg_solr, or install with composer composer require arckinteractive/elgg_solr:~2.0

2. In Admin > Plugins, reorder the elgg_solr plugin to be positioned under search plugin, and enable it

3. Create a new Solr instance and configure it:

   • Make sure that /<instance>/conf/solrconfig.xml is set to use classic index schema: <schemaFactory class="ClassicIndexSchemaFactory"></schemaFactory>
   • Copy contents of install/schema.xml (or install/schema.solr5.xml for Solr 5+) included in the root of the plugin to /<instance>/conf/schema.xml
     • Copy contents of install/solrconfig.solr5.xml to `//conf/solrconfig.xml if using solr 5

4. Update elgg_solr plugin settings to point to the new Solr instance

5. Trigger a reindex from the plugin setting page

6. Ensure that daily cron is configured and active

Plugin hooks

search, <search_type>

search, <entity_type>

search, <entity_type>:<entity_subtype>

These hooks can be used to modify search criteria

elgg_solr:index, <entity_type>

elgg_solr:index, <entity_type>:<entity_subtype>

elgg_solr:index, annotation

These hooks can be used to customize indexed fields

elgg_solr:can_index, annotation

Allows to add annotations to index by name

elgg_solr:access, entities

Allows plugins to add additional access queries.

Indexing

Tuning indexed values

Indexed values can be customized using 'elgg_solr:index',<entity_type>' hook:

elgg_register_plugin_hook_handler('elgg_solr:index', 'object', function($hook, $type, $return, $params) {

	$entity = elgg_extract('entity', $params);
	if (!$entity instanceof Event) {
		return;
	}

	$return->custom_field_s = $entity->custom_field;
	$return->start_time_i = $entity->start_time;
	return $return;
});

Adding annotations to index

To add an annotation to the index, add annotation name to the return of the 'elgg_solr:can_index','annotation':

elgg_register_plugin_hook_handler('elgg_solr:can_index', 'annotation', function($hook, $type, $return) {
	$return[] = 'revision';
	return $return;
});

Indexed values

Entity

• id - guid
• type - entity type
• subtype - entity subtype
• owner_guid - guid of the owner
• container_guid - guid of the container
• access_id - access level
• title - title
• name - name
• description - description
• time_created - timestamp of the creation
• time_updated_i - timestamp of the last update
• enabled - is entity enabled
• tag_<tag_name>_ss - tags for registered tag metadata names
• has_pic_b - flag indicating that entity has an uploaded icon
• responses_thread_i - guid of the comment/reply thread root
• responses_is - guids of comments/replies
• responses_count_i - total count of comments/replies
• likes_count_i - total count of likes

User

In addition to Entity fields:

• username - username
• profile_<field_name>_s - profile fields with a single value
• profile_<field_name>_ss - profile fields with multiple values (tags)
• groups_is - guids of groups a user is member of
• groups_count_i - total number of groups a user is a member of
• friends_is - guids of user's friends
• friends_count_i - total number of friends
• last_login_i - timestamp of the last login
• last_action_i - timestamp of the last activity
• has_pic_b - flag indicating that user has an avatar

Group

In addition to Entity fields:

• group_<field_name>_s - profile fields with a single value
• group_<field_name>_ss - profile fields with multiple values (tags)
• members_is - guids of group members
• members_count_i - total number of group members

File

To index file contents, enable extraction (extract_handler) in plugin settings.

In addition to Entity fields:

• attr_content - extracted contents
• simpletype_s - simple type (e.g. image, document etc)
• mimetype_s - detected mime type (e.g. application/json)
• originalfilename_s - original name of the uploaded file
• filesize_i - file size in bytes