Surface references via api query property

* The query request prop=references will return a JSON blob of all
references in the page
* Conveniently references are returned with an array id key that corresponds
to an anchor tag in the HTML
* When references storage is disabled the API request will trigger an
error.

Bug: T123290
Change-Id: I81a965bcb47d17df18f1e415e3c25f88f6b48ffc

ApiQueryReferences.php

@@ -0,0 +1,94 @@
+<?php
+
+/**
+ * Expose reference information for a page via prop=references API.
+ *
+ * @see https://www.mediawiki.org/wiki/Extension:Cite#API
+ *
+ * @license WTFPL 2.0
+ */
+class ApiQueryReferences extends ApiQueryBase {
+
+	public function __construct( $query, $moduleName ) {
+		parent::__construct( $query, $moduleName, 'rf' );
+	}
+
+	public function getAllowedParams() {
+		return [
+		   'continue' => [
+		       ApiBase::PARAM_HELP_MSG => 'api-help-param-continue',
+		   ],
+		];
+	}
+
+	public function execute() {
+		$config = ConfigFactory::getDefaultInstance()->makeConfig( 'cite' );
+		if ( !$config->get( 'CiteStoreReferencesData' ) ) {
+			$this->dieUsage( 'Cite extension reference storage is not enabled', 'citestoragedisabled' );
+		}
+		$params = $this->extractRequestParams();
+		$titles = $this->getPageSet()->getGoodTitles();
+		ksort( $titles );
+		if ( !is_null( $params['continue'] ) ) {
+			$startId = (int)$params['continue'];
+			// check it is definitely an int
+			$this->dieContinueUsageIf( strval( $startId ) !== $params['continue'] );
+		} else {
+			$startId = false;
+		}
+
+		foreach ( $titles as $pageId => $title ) {
+			// Skip until you have the correct starting point
+			if ( $startId !== false && $startId !== $pageId ) {
+				continue;
+			} else {
+				$startId = false;
+			}
+			$storedRefs = Cite::getStoredReferences( $title );
+			$allReferences = array();
+			// some pages may not have references stored
+			if ( $storedRefs !== false ) {
+				// a page can have multiple <references> tags but they all have unique keys
+				foreach ( $storedRefs['refs'] as $index => $grouping ) {
+					foreach ( $grouping as $group => $members ) {
+						foreach ( $members as $name => $ref ) {
+							$ref['name'] = $name;
+							$key = $ref['key'];
+							if ( is_string( $name ) ) {
+								$id = Cite::getReferencesKey( $name . '-' . $key );
+							} else {
+								$id = Cite::getReferencesKey( $key );
+							}
+							$ref['group'] = $group;
+							$ref['reflist'] = $index;
+							$allReferences[$id] = $ref;
+						}
+					}
+				}
+			}
+			// set some metadata since its an assoc data structure
+			ApiResult::setArrayType( $allReferences, 'kvp', 'id' );
+			// Ship a data representation of the combined references.
+			$fit = $this->addPageSubItems( $pageId, $allReferences );
+			if ( !$fit ) {
+				$this->setContinueEnumParameter( 'continue', $pageId );
+				break;
+			}
+		}
+	}
+
+	public function getCacheMode( $params ) {
+		return 'public';
+	}
+
+	/**
+	 * @see ApiBase::getExamplesMessages()
+	 */
+	protected function getExamplesMessages() {
+		return array(
+			'action=query&prop=references&titles=Albert%20Einstein' =>
+				'apihelp-query+references-example-1',
+		);
+	}
+
+}

extension.json

@@ -18,6 +18,11 @@
 		"cite": "i18n",
 		"ve-cite": "modules/ve-cite/i18n"
 	},
+	"APIPropModules": {
+		"references": {
+			"class": "ApiQueryReferences"
+		}
+	},
 	"Hooks": {
 		"ParserFirstCallInit": [
 			"Cite::setHooks"
@@ -164,6 +169,9 @@
 	"VisualEditorPluginModules": [
 		"ext.cite.visualEditor"
 	],
+	"ConfigRegistry": {
+		"cite": "GlobalVarConfig::newInstance"
+	},
 	"config": {
 		"AllowCiteGroups": true,
 		"CiteCacheReferences": false,
@@ -171,6 +179,7 @@
 		"CiteCacheReferencesDataOnParse": false
 	},
 	"AutoloadClasses": {
+		"ApiQueryReferences": "ApiQueryReferences.php",
 		"Cite": "Cite_body.php",
 		"CiteHooks": "CiteHooks.php",
 		"CiteDataModule": "CiteDataModule.php",

i18n/en.json

@@ -15,6 +15,8 @@
 			"Ævar Arnfjörð Bjarmason"
 		]
 	},
+	"apihelp-query+references-description": "Return a data representation of references associated with the given pages.",
+	"apihelp-query+references-example-1": "References associated with <kbd>Albert Einstein</kbd>.",
 	"cite-desc": "Adds <nowiki><ref[ name=id]></nowiki> and <nowiki><references/></nowiki> tags, for citations",
 	"cite_error": "Cite error: $1",
 	"cite_error_ref_numeric_key": "Invalid <code>&lt;ref&gt;</code> tag;\nname cannot be a simple integer. Use a descriptive title",

i18n/qqq.json

@@ -15,6 +15,8 @@
 			"Umherirrender"
 		]
 	},
+	"apihelp-query+references-description": "{{doc-apihelp-description|query+references}}",
+	"apihelp-query+references-example-1": "{{doc-apihelp-example|query+references}}",
 	"cite-desc": "{{desc|name=Cite|url=https://www.mediawiki.org/wiki/Extension:Cite}}",
 	"cite_error": "Cite extension.\n\nUsed when there are errors in ref or references tags.\n\nParameters:\n* $1 - an error message",
 	"cite_error_ref_numeric_key": "Cite extension. Error message shown if the name of a ref tag only contains digits. Examples that cause this error are <code><nowiki><ref name=\"123\" /></nowiki></code> or <code><nowiki><ref name=\"456\">input</ref></nowiki></code>",