Use feature management for search in header

This will allow us to add the A/B testing requirement for logged in
users.

In preparation for the new A/B test requirement, a custom requirement
is added as the feature management system does not
support OR operations and the desired effect is the case where:

* the SearchInHeader feature flag has been enabled
* OR the SearchInHeaderABTest feature flag has been enabled and the user is bucketed

Bug: T259250
Change-Id: If948603bd598e1b5597345f4268736417f4c3a24

includes/Constants.php

@@ -79,6 +79,11 @@ final class Constants {
 	 */
 	public const CONFIG_SEARCH_IN_HEADER = 'VectorIsSearchInHeader';
 
+	/**
+	 * @var string
+	 */
+	public const REQUIREMENT_SEARCH_IN_HEADER = 'VectorIsSearchInHeaderIsEnabled';
+
 	/**
 	 * @var string
 	 */
@@ -111,6 +116,11 @@ final class Constants {
 	 */
 	public const FEATURE_LATEST_SKIN = 'LatestSkin';
 
+	/**
+	 * @var string
+	 */
+	public const FEATURE_SEARCH_IN_HEADER = 'TemporarySearchInHeader';
+
 	/**
 	 * @var string
 	 */

includes/FeatureManagement/Requirements/SearchInHeaderRequirement.php

@@ -0,0 +1,70 @@
+<?php
+
+/**
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
+ * http://www.gnu.org/copyleft/gpl.html
+ *
+ * @file
+ * @since 1.36
+ */
+
+namespace Vector\FeatureManagement\Requirements;
+
+use Config;
+use Vector\Constants;
+use Vector\FeatureManagement\Requirement;
+
+/**
+ * Check whether the search should be part of the header or part of
+ * the tabs (as in the old design).
+ * The search in header is enabled if:
+ *  - the associated feature flag has been enabled
+ *
+ * @unstable
+ *
+ * @package Vector\FeatureManagement\Requirements
+ * @internal
+ */
+final class SearchInHeaderRequirement implements Requirement {
+	/**
+	 * @var Config
+	 */
+	private $config;
+
+	/**
+	 * This constructor accepts all dependencies needed to determine
+	 * whether search in header is enabled for current user and config.
+	 *
+	 * @param \Config $config
+	 */
+	public function __construct( Config $config ) {
+		$this->config = $config;
+	}
+
+	/**
+	 * @inheritDoc
+	 */
+	public function getName() : string {
+		return Constants::REQUIREMENT_SEARCH_IN_HEADER;
+	}
+
+	/**
+	 * @inheritDoc
+	 * @throws \ConfigException
+	 */
+	public function isMet() : bool {
+		return (bool)$this->config->get( Constants::CONFIG_SEARCH_IN_HEADER );
+	}
+}

includes/Hooks.php

@@ -274,7 +274,9 @@ class Hooks {
 		//
 		// See https://codesearch.wmcloud.org/deployed/?q=skin-vector-search- for an up-to-date
 		// list.
-		if ( self::getConfig( Constants::CONFIG_SEARCH_IN_HEADER ) ) {
+
+		$featureManager = VectorServices::getFeatureManager();
+		if ( $featureManager->isFeatureEnabled( Constants::FEATURE_SEARCH_IN_HEADER ) ) {
 			$bodyAttrs['class'] .= ' skin-vector-search-header';
 		} else {
 			$bodyAttrs['class'] .= ' skin-vector-search-header-legacy';

includes/ServiceWiring.php

@@ -27,6 +27,7 @@ use Vector\Constants;
 use Vector\FeatureManagement\FeatureManager;
 use Vector\FeatureManagement\Requirements\DynamicConfigRequirement;
 use Vector\FeatureManagement\Requirements\LatestSkinVersionRequirement;
+use Vector\FeatureManagement\Requirements\SearchInHeaderRequirement;
 use Vector\SkinVersionLookup;
 
 return [
@@ -66,6 +67,23 @@ return [
 			]
 		);
 
+		// Feature (temporary): search in header
+		// ========================================
+		$featureManager->registerRequirement(
+			new SearchInHeaderRequirement(
+				$services->getMainConfig()
+			)
+		);
+
+		$featureManager->registerFeature(
+			Constants::FEATURE_SEARCH_IN_HEADER,
+			// Requirements
+			[
+				Constants::REQUIREMENT_FULLY_INITIALISED,
+				Constants::REQUIREMENT_SEARCH_IN_HEADER
+			]
+		);
+
 		return $featureManager;
 	}
 ];

includes/SkinVector.php

@@ -24,6 +24,7 @@
 
 use MediaWiki\MediaWikiServices;
 use Vector\Constants;
+use Vector\VectorServices;
 
 /**
  * Skin subclass for Vector
@@ -99,6 +100,8 @@ class SkinVector extends SkinMustache {
 		$out = $skin->getOutput();
 		$title = $out->getTitle();
 
+		$featureManager = VectorServices::getFeatureManager();
+
 		// Naming conventions for Mustache parameters.
 		//
 		// Value type (first segment):
@@ -130,7 +133,7 @@ class SkinVector extends SkinMustache {
 
 			'html-categories' => $skin->getCategories(),
 			'data-footer' => $this->getFooterData(),
-			'is-search-in-header' => $this->getConfig()->get( Constants::CONFIG_SEARCH_IN_HEADER ),
+			'is-search-in-header' => $featureManager->isFeatureEnabled( Constants::FEATURE_SEARCH_IN_HEADER ),
 
 			// Header
 			'data-logos' => ResourceLoaderSkinModule::getAvailableLogos( $this->getConfig() ),