Solr Search for WordPress Plugin

Search is critical for your site, but the default search for WordPress leaves a lot to be desired. Improve your user experience with the Apache Solr search engine for your WordPress website.

• Fast results, with better accuracy.
• Enables faceting on fields such as tags, categories, author, and page type.
• Indexing and faceting on custom fields.
• Drop-in support for WP_Query with the solr_integrate parameter set to true.
• Completely replaces default WordPress search, just install and configure.
• Completely integrated into default WordPress theme and search widget.
• Very developer-friendly: uses the modern Solarium library

Development

This plugin is under active development on GitHub:

https://github.com/pantheon-systems/solr-power

Please feel free to file issues there. Pull requests are also welcome! See CONTRIBUTING.md for information on contributing.

For further documentation, such as available filters and working with the SolrPower_Api class directly, please see the project wiki:

https://github.com/pantheon-systems/solr-power/wiki

You may notice there are two sets of tests running, on two different services:

• PHPUnit test suite against a Solr instance.
• The Behat test suite against a Pantheon site, to ensure the plugin’s compatibility with the Pantheon platform.

Both of these test suites can be run locally, with a varying amount of setup.

PHPUnit requires the WordPress PHPUnit test suite, and access to a database with name wordpress_test. If you haven’t already configured the test suite locally, you can run bash bin/install-wp-tests.sh wordpress_test root '' localhost. You’ll also need access to a running Solr instance, in order to run the unit tests against Solr.

Behat requires a Pantheon site with Solr enabled. Once you’ve created the site, you’ll need install Terminus, and set the TERMINUS_TOKEN, TERMINUS_SITE, and TERMINUS_ENV environment variables. Then, you can run ./bin/behat-prepare.sh to prepare the site for the test suite.

Note that dependencies are installed via Composer and the vendor directory is not committed to the repository. You will need to run composer install locally for the plugin to function. You can read more about Composer here

WP-CLI Support

This plugin has WP-CLI support.

All Solr Power related commands are grouped into the wp solr command, see an example:

$ wp solr usage: wp solr check-server-settings or: wp solr delete [<id>...] [--all] or: wp solr index [--batch=<batch>] [--batch_size=<size>] [--post_type=<post-type>] or: wp solr info [--field=<field>] [--format=<format>] or: wp solr optimize-index or: wp solr repost-schema or: wp solr stats [--field=<field>] [--format=<format>] See 'wp help solr <command>' for more information on a specific command. 

You can see more details about the commands using wp help solr:

**NAME** wp solr **DESCRIPTION** Perform a variety of actions against your Solr instance. **SYNOPSIS** wp solr <command> **SUBCOMMANDS** check-server-settings Check server settings. delete Remove one or more posts from the index. index Index all posts for a site. info Report information about Solr Power configuration. optimize-index Optimize the Solr index. repost-schema Repost schema.xml to Solr. stats Report stats about indexed content.<h3>WP_Query Integration</h3> 

Use Solr in a custom WP_Query instead of querying a database. Add 'solr_integrate' => true to the query arguments.

NOTE: Currently, only basic queries, tax_query, meta_query and date_query are supported. See examples/example.custom_WP_Query.php for an example.

A meta_query can use the following compare operators:

• '='
• '!='
• '>'
• '>='
• '<'
• '<='
• 'LIKE'
• 'NOT LIKE'
• 'IN'
• 'NOT IN'
• 'BETWEEN'
• 'NOT BETWEEN'
• 'EXISTS'
• 'NOT EXISTS'

('REGEXP', 'NOT REGEXP', and 'RLIKE' are not supported.)

Configuration Tips

Searching by author name

To support searching by author name (e.g. where “Pantheon” would return posts authored by the “Pantheon” user), add the following to your custom schema.xml:

 <copyField source="post_author" dest="text"/> 

Boosting relevancy score by publish date

The following guidance can be used to extend the Solr index and modify boosts beyond just this example.

To support math functions on dates, you must add a custom schema.xml to Solr and reindex with the new schema.

Add the following to schema.xml:

 <!-- Add to <types> --> <!-- See: https://lucene.apache.org/solr/6_2_0/solr-core/org/apache/solr/schema/TrieDateField.html --> <fieldType name="tdate" class="solr.TrieDateField" omitNorms="true" precisionStep="6" positionIncrementGap="0"/> <!-- Add to <fields> --> <field name="post_date_iso" type="tdate" indexed="true" stored="true" required="true" /> 

Add the following to your functions.php file.

 <?php /** * Hooks into the document build process to add post date field in proper format. */ function my_solr_build_document( $doc, $post_info ) { $post_time = strtotime( $post_info->post_date ); // Matches format required for TrieDateField $doc->setField( 'post_date_iso', gmdate( 'c\Z', $post_time ) ); return $doc; } add_filter( 'solr_build_document', 'my_solr_build_document', 10, 2 ); /** * Hooks into query processor, Dismax, to add publish date boost. * See: https://www.metaltoad.com/blog/date-boosting-solr-drupal-search-results */ function my_solr_dismax_query( $dismax ) { $dismax->setQueryParser( 'edismax' ); $dismax->setBoostQuery( 'recip(abs(ms(NOW/HOUR,post_date_iso),3.16e-11,1,1))' ); return $dismax; } add_filter( 'solr_dismax_query', 'my_solr_dismax_query' ); 

Common issues

• Failing to post the schema.xml will result in an error during indexing, “Missing post_date_iso field.”
• If you have the field and type in the schema, but don’t add the solr_build_document filter, you will get a similar error.
• If the post_date_iso field is missing from the index, Solr will ignore this boost and return regular results.
• Trying to use a regular date field for the boost query will result in an error in the request instead of results.

Explicit Commit vs Autocommit

Once solr has sent the data to the solr server, solr must COMMIT the data to the index and adjust the index and relevancy ratings accordingly before that data can appear in search results.

By default, Solr Search for WordPress has auto-commit disabled. The index is committed when the uncommitted item is two minutes old, or the cron runs. By default, the cron runs on the Pantheon platform every hour.

When autocommit is enabled, Solr Search for WordPress commits data when it sends every post. When running on Pantheon, we recommend leaving autocommit disabled to aid overall site performance.

To enable autocommit, add the following to wp-config.php or an mu-plugin.

 define( 'SOLRPOWER_DISABLE_AUTOCOMMIT', false ); 

To force-commit data outside of a normal cron run, from the command line, you can run the command below or simply force a cron-run.

 wp solr commit 

The Solr Power plugin can be installed just like you’d install any other WordPress plugin.

Because Solr Power is intended to be a bridge between WordPress and the Apache Solr search engine, you’ll need access to a functioning Solr 3.6 instance for the plugin to work as expected. This plugin does not support other versions of Solr. The plugin also requires PHP 7.1 or higher.

If you’re using the Solr Power plugin on Pantheon, setting up Apache Solr is as easy as enabling the Apache Solr add-on in your Pantheon dashboard. Once you’ve done so:

1. Configure which post types, taxonomies and custom fields to index by going to the Indexing tab of the Solr Power settings page.
2. Index your existing content by going to the plugin options screen and selecting the applicable Actions:
   • • Index Searchable Post Types
3. Search on!
4. See the examples/templates directories for more rich implementation guidelines.

If you’re using the Solr Power plugin elsewhere, you’ll need to install and configure Apache Solr. On a Linux environment, this involves four steps:

1. Install the Java Runtime Environment.
2. Run ./bin/install-solr.sh to install and run Apache Solr on port 8983.
3. Configuring Solr Power to use this particular Solr instance by setting the PANTHEON_INDEX_HOST and PANTHEON_INDEX_PORT environment variables.
4. Copying schema.xml to the Solr configuration directory (a path similar to solr/conf/schema.xml).

Alternatively, there are a couple of community-maintained Docker containers you may be able to use: kalabox/pantheon-solr, kshaner/solr.

In a local development environment, you can point Solr Power to a custom Solr instance by creating a MU plugin with:

<?php /** * Define Solr host IP, port, scheme and path * Update these as necessary if your configuration differs */ putenv( 'PANTHEON_INDEX_HOST=192.168.50.4' ); putenv( 'PANTHEON_INDEX_PORT=8983' ); add_filter( 'solr_scheme', function(){ return 'http'; }); define( 'SOLR_PATH', '/solr/wordpress/' ); 

** Note for Lando users **

If you are using lando for development, the MU plugin is not needed. Lando auto configures everything for your local environment to connect to the docker index it maintains and if you overrite the ENV variables it will mess with that configuration.

2.5.3 (April 24, 2024)

• Fixes a very old bug that would cause tax queries to be built incorrectly. [#622] (props @offshorealert)

2.5.2 (September 12, 2023)

• Fix incompatibility with Object Cache Pro when running “wp solr index” [#611]

2.5.1

• Fix Solr not indexing automatically [#598]
• Fixed issue with empty/zero value for posts_per_page [#599] (props @threeiem)

2.5.0

• Updates CONTRIBUTING.md [#585] [#594]
• Fixes typo in var which caused undefined notice [#582]
• Update Composer dependencies [#576] [#574] [#573]
• Updates security policy [#589]
• Disable auto-commit by default. [#591]

2.4.5 (April 9, 2023)

• Fixes missing vendor/ directory in previous release [#580]

2.4.4 (April 7, 2023)

• Update Composer dependencies [#576] [#574] [#573]
• Fix failing tests [#577]
• Update tested up to version

2.4.3 (January 19, 2022)

• Include schema.xml in release distribution [#568]

2.4.2 (December 2, 2022)

• Re-add changelog heading to readme.txt [#564]

2.4.1 (December 1, 2022)

• Fixes the WordPress readme.txt [#562]

2.4.0 (November 30, 2022)

• Adds Github Actions for building tag and deploying to wp.org. Add CONTRIBUTING.md. [#551]
• Added SOLRPOWER_DISABLE_AUTOCOMMIT to disable autocommitting of posts, moved CHANGELOG to it’s own file, added $post->score value to parsed search results [#559]

2.3.3 (September 28, 2022)

• Fixes issue where options could not be saved [#541]
• Enforces network activation requirement for WordPress multisite [#538]

2.3.2 (April 1, 2022)

• Fixes query filtering for 'fields' => 'id=>parent' [#528].

2.3.1 (March 29, 2022)

• Adapts posts_pre_query() return values based on ‘fields’ argument [#522].

2.3.0 (March 29, 2022)

• Removes incorrect use of array_map( 'get_post' ) in posts_pre_query [#521].

2.2.6 (February 22, 2022)

• Fixes PHP 8 deprecations in class-solrpower-options.php [#513].

2.2.5 (July 27, 2021)

• Switches to wp_strip_all_tags() to remove style and script tag content [#500].

2.2.4 (May 5, 2021)

• Introduces SOLRPOWER_DISABLE_QUERY_ALT constant for disabling setQueryAlternative behavior [#495].

2.2.3 (March 8, 2021)

• Incorporates the value for $_ENV['FILEMOUNT'] when indicating path for schema.xml [#492].

2.2.2 (December 1, 2020)

• Updates various Composer dependencies [#477].
• Updates README to include detail on how to use TrieDateField for publish date [#466].

2.2.1 (July 13, 2020)

• Avoids pinging Solr unless we actually need, to avoid unnecessary requests [#458].

2.2.0 (May 5, 2020)

• Uses posts_pre_query hook to support use of ‘fields’ in WP_Query [#448].

2.1.4 (April 24, 2020)

• Ensures highlighting is also applied to the post excerpt [#446].

2.1.3 (November 16, 2019)

• Add solr_power_ajax_search_query_args filter to modify AJAX search query arguments [#432].

2.1.2 (August 28, 2019)

• Adds solr_is_private_blog filter to allow control over whether a blog is indexed [#423].

2.1.1 (August 14, 2019)

• Uses some fancy composer magic to unblock WordPress.org plugin updates [#418].

2.1.0 (May 22, 2019)

• Introduces solr_index_stat filter for allowing additional information to be included [#396].
• Introduces solr_facet_operator filter for allowing facet operator to be overridden [#388].
• Ensures warning message appears when activating across the entire network [#399].
• Parses <h1> tags in Solr error response, in addition to <title> [#407].
• Fixes incorrect variable name when outputting schema error message [#404].

2.0.0

• Fix PHP 7 warning caused by bad conditional
• Ensure $post->post_author remains user ID when processing WP_Query
• Add a test case asserting that post_title and post_content are not bolded
• Update Solarium to 4.1.0 and other dependencies updates as needed
• Run automated tests against PHP 7.1
• Increase the minimum supported PHP version to 7.1

1.5.0

• Adds support for queries using post__in and post__not_in.
• Clears batch cache when entire index is deleted.
• CLI: Errors early when there are no posts to index.
• Update Composer dependencies

1.4.1

• Introduce batch_size argument for wp solr index
• Ensure custom taxonomies are included in widget facets
• Mention available Docker containers in README
• Properly handle negative integers when indexing and querying
• Increase precision of test_wp_query_failed_ping to avoid racy failures
• Catch exception when $search->getData() fails
• Remove unused global imports for $current_blog
• Properly escape dismax query strings
• POST actions to admin.php in network admin
• Define checked files in PHPCS config so phpcs can easily be run
• Remove unused global imports for $current_blog
• Define checked files in PHPCS config so phpcs can easily be run
• Rename PHPCS config to correct name

1.4.0

• Bumps minimum supported version to WordPress 4.6.
• Updates bundled Solarium library to 3.8.1.
• Fixes Solr queries using orderby=>meta_value_num [#299].
• Use $_SERVER['HOME'] as a reliable way of finding the cert on Pantheon [#314].

1.3.0

• Add .distignore file for wp dist-archive solr-power
• Make Solr in the admin opt-in only using the solr_allow_admin filter
• Error early when PANTHEON_ENVIRONMENT isn’t set
• Clarify error message when environment variables aren’t set
• Mention copying schema.xml and supported Solr version in README
• Include original plugin attribution in the copyright notice
• Boost post_title more than post_content with sane boost values
• Add missing filter for custom fields
• Boost posts with matching titles to the top of results
• Remove duplicate options when initializing them
• Match author name in search results
• Bug fixes
• Adhere to WordPress coding standards in PHP files

1.2.0

• Add multisite support
• Respect all query vars when searching with WP_Query
• Display error from schema submit response when Solr includes one

1.1.0

• Introduce a new class for managing batch indexes
• Rewrite wp solr index to provide more verbosity
• Make batch indexes resumeable by logging paged to an option
• Remove old wp solr index code
• Fire solr_power_index_all_finished action when indexing is complete
• Ensure a completion message displays after indexing is complete
• Fix a bug around Solr taking over searches in wp-admin
• Properly apply the solr_allow_admin and solr_allow_ajax filters
• Add solr_boost_query filter for boosted items
• Add solr_dismax_query filter for Dismax
• Add get_post_types and get_post_statuses helper methods
• Remove unnecessary get_env call
• Add solr_post_status filter
• Add missing solr_post_types filter to get_post_types call
• Use PANTHEON_INDEX_PORT instead of hard-coded port in curl

1.0.0

• Add Ajax functionality to the facet search widget
• Add date_query support to WP_Query Integration
• Allow s parameter for WP_Query when Solr is enabled
• Checks for searchable post type before indexing modified post
• Test with WordPress 4.7
• Add solr_power_index_all_finished action when indexing all posts is complete
• Allow post_title and post_content to score higher
• Make sure that integers and float values are actually of that type. Otherwise, Solr will fail to index the document.

0.6.0

• Advanced WP_Query Integration – Meta Queries, Tax Queries
• Translatable strings standardized
• Facet query fixes
• Hide schema submit option if not on the Pantheon platform
• Added a method for API status
• Document available filters
• Fixed single quote/character issues in the facet widget

0.5.0

• Add facet search widget
• Update options page internals to utilize WordPress settings API
• Add Behat tests to ensure the plugin’s compatibility with the Pantheon platform.
• Defork Solarium and update it to version 3.6.0

0.4.1

• Do not allow plugin activation if the PANTHEON_INDEX_HOST or PANTHEON_INDEX_PORT environment variables are not set. Instead, show an admin notice to the user advising them to configure the environment variables.

0.4

• Auto submission of schema.xml
• Moved legacy functions to a separate file
• PHP version check – warn in the WordPress dashboard and disable Solr Power plugin if the PHP version is less than 5.4

0.3

• Bug fixes
• Settings page updates
• Filters for AJAX/Admin integration
• Indexing all publicly queryable post types
• Debug Bar Extension
• Default sort option on settings page
• Initial WP CLI integration

0.2

• Works “out of the box” by overriding WP_Query()
• Much improved internal factoring

0.1

• Initial alpha release (GitHub only)

0.0

• Note this started as a fork of this wonderful project: https://github.com/mattweber/solr-for-wordpress