Recommend databases based on result facets

config/vufind/EDS.ini

@@ -38,6 +38,7 @@ default_view         = brief
 ; sections below.
 ;default_top_recommend[] = TopFacets:FacetsTop:EDS
 default_side_recommend[] = SideFacets:Facets:CheckboxFacets:EDS
+;default_side_recommend[] = Databases:5:EDS
 ;default_noresults_recommend[] = SwitchTab
 default_noresults_recommend[] = SwitchType
 default_noresults_recommend[] = RemoveFilters
@@ -340,3 +341,27 @@ AU = None
 ; documentation on options for different adapters.
 ; ttl, Time to Live, i.e. cache entry life time in seconds. 300 seconds by default.
 ;options[ttl] = 300
+
+; This section supports the Databases recommendation module,
+; which displays a list of the results' databases, each linking
+; to that database's individual website.
+[Databases]
+
+; Define the facet hierarchy path leading to each database.
+; For EDS (the databases are at ContentProvider/list):
+;resultFacet[] = 'ContentProvider'
+;resultFacet[] = 'list'
+
+; For each database facet, define the key to the database name
+; For EDS:
+;resultFacetNameKey = 'value'
+
+; Load database URLs from LibGuides.  Default is false.
+; Requires configuration in LibGuidesAPI.ini. 
+;useLibGuides = true
+
+; Map of database name (matching EDS API 'DbLabel' value) to website URL.
+; These databases are added to any retrieved from LibGuides, and override
+; the LibGuides URLs if the same name is present here.
+;url[Expensive Science Database] = https://some.url
+;url[Cool Humanities Database] = https://another.url

config/vufind/LibGuidesAPI.ini

@@ -33,6 +33,15 @@ api_base_url = https://lgapi-us.libapps.com/1.2
 ; Duration (seconds) to cache response data.  Default is 600.
 ;cache_lifetime = 600
 
+; Calls to GET (...)/az endpoint
+; Note this is not used for the LibGuidesAZ search
+; implementation; see LibGuidesAZ.ini for that.
+; This is used where the full list of databases is needed
+; by the Databases recommendation module.
+[GetAZ]
+; Duration (seconds) to cache response data.  Default is 600.
+;cache_lifetime = 600
+
 ; Configuration for LibGuidesProfile recommendation module
 [Profile]
 ; Enable one or more strategies for matching the best profile

config/vufind/searches.ini

@@ -262,6 +262,10 @@ WorkKeys = year
 ;       Display catalog search results matching the terms found in the specified
 ;       GET parameter (default = "lookfor"), limited to a specified number of
 ;       matches (default = 5).  This is designed for use with non-catalog modules.
+; Databases:[result limit]:[ini name]
+;       Displays a list of the databases referenced in EDS or similar facets, each
+;       linking to its individual website.  The .ini file must contain a [Databases]
+;       section with the relevant configuration; see example in EDS.ini.
 ; DPLATerms:[collapsed]
 ;       Display results from the DPLA catalog. Provide a boolean to have the sidebar
 ;       collapsed or open on page load.

languages/en.ini

@@ -301,6 +301,8 @@ Created = "Created"
 csrf_validation_failed = "The request could not be processed. Please try again."
 Data Set = "Data Set"
 Database = "Database"
+databases = "Search Relevant Databases"
+databases_intro = "Search directly in databases for enhanced functionality."
 Date = "Date"
 Date of birth = "Date of birth"
 Date of death = "Date of death"

module/VuFind/src/VuFind/Connection/LibGuides.php

@@ -122,14 +122,57 @@ public function __construct(
      * if an error occurs
      */
     public function getAccounts()
+    {
+        if (!$this->authenticateAndSetHeaders()) {
+            return null;
+        }
+
+        $result = $this->doGet(
+            $this->baseUrl . '/accounts?expand=profile,subjects'
+        );
+
+        if (isset($result->errorCode)) {
+            return null;
+        }
+        return $result;
+    }
+
+    /**
+     * Load all LibGuides AZ databases.
+     *
+     * @return object|null A JSON object of all LibGuides databases, or null
+     * if an error occurs
+     */
+    public function getAZ()
+    {
+        if (!$this->authenticateAndSetHeaders()) {
+            return null;
+        }
+
+        $result = $this->doGet(
+            $this->baseUrl . '/az'
+        );
+
+        if (isset($result->errorCode)) {
+            return null;
+        }
+        return $result;
+    }
+
+    /**
+     * Authenticate to the LibGuides API and set authentication headers.
+     *
+     * @return bool Indicates if authentication succeeded.
+     */
+    protected function authenticateAndSetHeaders()
     {
         $tokenData = $this->authenticateWithClientCredentials(
             $this->baseUrl . '/oauth/token',
             $this->clientId,
             $this->clientSecret
         );
         if (!$tokenData) {
-            return null;
+            return false;
         }
 
         $headers = [];
@@ -143,10 +186,21 @@ public function getAccounts()
         $headers[] = 'User-Agent: ' . $this->userAgent;
 
         $this->client->setHeaders($headers);
+
+        return true;
+    }
+
+    /**
+     * Perform a GET request to the LibGuides API.
+     *
+     * @param string $url Full request url
+     *
+     * @return object|null A JSON object of the response data, or null if an error occurs
+     */
+    protected function doGet($url)
+    {
         $this->client->setMethod('GET');
-        $this->client->setUri(
-            $this->baseUrl . '/accounts?expand=profile,subjects'
-        );
+        $this->client->setUri($url);
         try {
             $response = $this->client->send();
         } catch (Exception $ex) {