Add ISSN and open access filters to OpenAlex

lib/l10n/app_en.arb

@@ -193,6 +193,10 @@
   "@publishedBetween":{},
   "noFilter": "No filter",
   "@noFilter":{},
+  "issnFilter":"ISSN filter",
+  "@issnFilter":{},
+  "openAccessOnly":"Open access only",
+  "@openAccessOnly":{},
   "selectStartDate": "Select start date",
   "@selectStartDate":{},
   "selectEndDate": "Select end date",

lib/screens/article_search_results_screen.dart

@@ -89,6 +89,8 @@ class _ArticleSearchResultsScreenState
           widget.queryParams['sortField'],
           widget.queryParams['sortOrder'],
           widget.queryParams['dateFilter'],
+          widget.queryParams['issnFilter'],
+          widget.queryParams['isOpenAccess'] ?? false,
           page: pageKey,
         );
 

lib/services/openAlex_api.dart

@@ -11,8 +11,14 @@ class OpenAlexApi {
   static const String worksEndpoint = '/works?';
   static String? apiKey;
 
-  static Future<List<journalWorks.Item>> getOpenAlexWorksByQuery(String query,
-      int scope, String? sortField, String? sortOrder, String? dateFilter,
+  static Future<List<journalWorks.Item>> getOpenAlexWorksByQuery(
+      String query,
+      int scope,
+      String? sortField,
+      String? sortOrder,
+      String? dateFilter,
+      String? issnFilter,
+      bool isOpenAccess,
       {int page = 1}) async {
     final prefs = await SharedPreferences.getInstance();
     apiKey = prefs.getString('openalex_api_key');
@@ -41,6 +47,21 @@ class OpenAlexApi {
         filterPart += ',$dateFilter';
       }
     }
+    if (issnFilter != null && issnFilter.isNotEmpty) {
+      if (filterPart.isEmpty) {
+        filterPart = 'filter=$issnFilter';
+      } else {
+        filterPart += ',$issnFilter';
+      }
+    }
+
+    if (isOpenAccess) {
+      if (filterPart.isEmpty) {
+        filterPart = 'filter=is_oa:true';
+      } else {
+        filterPart += ',is_oa:true';
+      }
+    }
 
     String sortPart = '';
     if (sortField != null && sortOrder != null) {

lib/widgets/article_openAlex_search_form.dart

@@ -19,6 +19,8 @@ class OpenAlexSearchFormState extends State<OpenAlexSearchForm> {
   String selectedSortOrder = '-';
   DateTime? _publishedAfter;
   DateTime? _publishedBefore;
+  final TextEditingController issnController = TextEditingController();
+  bool _isOpenAccess = false;
 
   String _dateMode = 'none';
   // bool _filtersExpanded = false;
@@ -33,6 +35,13 @@ class OpenAlexSearchFormState extends State<OpenAlexSearchForm> {
     _checkApiKey();
   }
 
+  @override
+  void dispose() {
+    issnController.dispose();
+    queryNameController.dispose();
+    super.dispose();
+  }
+
   void _addQueryPart(String type) {
     setState(() {
       if (queryParts.isNotEmpty && queryParts.last['type'] != 'operator') {
@@ -125,6 +134,7 @@ class OpenAlexSearchFormState extends State<OpenAlexSearchForm> {
     String? sortField = selectedSortField == '-' ? null : selectedSortField;
     String? sortOrder = selectedSortOrder == '-' ? null : selectedSortOrder;
     String? dateFilter;
+    String? issnFilter;
 
     String formatDate(DateTime d) => d.toIso8601String().split('T')[0];
 
@@ -139,6 +149,16 @@ class OpenAlexSearchFormState extends State<OpenAlexSearchForm> {
           "to_publication_date:${formatDate(_publishedBefore!)}";
     }
 
+    if (issnController.text.trim().isNotEmpty) {
+      final issns = issnController.text
+          .split(',')
+          .map((e) => e.trim())
+          .where((e) => e.isNotEmpty)
+          .join('|');
+
+      issnFilter = "locations.source.issn:$issns";
+    }
+
     try {
       showDialog(
         context: context,
@@ -182,8 +202,33 @@ class OpenAlexSearchFormState extends State<OpenAlexSearchForm> {
             }
           }
 
+          String issnPart = '';
+
+          if (issnFilter != null && issnFilter.isNotEmpty) {
+            if (searchField.startsWith('filter=')) {
+              issnPart = ',$issnFilter';
+            } else if (datePart.isNotEmpty) {
+              issnPart = ',$issnFilter';
+            } else {
+              issnPart = '&filter=$issnFilter';
+            }
+          }
+
+          String oaPart = '';
+          if (_isOpenAccess) {
+            if (searchField.startsWith('filter=')) {
+              oaPart = ',is_oa:true';
+            } else if (datePart.isNotEmpty || issnPart.isNotEmpty) {
+              oaPart = ',is_oa:true';
+            } else {
+              oaPart = '&filter=is_oa:true';
+            }
+          }
+
           queryString = '$searchField$query'
               '$datePart'
+              '$issnPart'
+              '$oaPart'
               '$selectedSortBy'
               '$selectedSortOrder';
           await dbHelper.saveSearchQuery(queryName, queryString, 'OpenAlex');
@@ -208,6 +253,8 @@ class OpenAlexSearchFormState extends State<OpenAlexSearchForm> {
               if (sortField != null) 'sortField': sortField,
               if (sortOrder != null) 'sortOrder': sortOrder,
               if (dateFilter != null) 'dateFilter': dateFilter,
+              if (issnFilter != null) 'issnFilter': issnFilter,
+              'isOpenAccess': _isOpenAccess,
             },
             source: 'OpenAlex',
           ),
@@ -281,6 +328,16 @@ class OpenAlexSearchFormState extends State<OpenAlexSearchForm> {
                 border: OutlineInputBorder(),
               ),
             ),
+            SizedBox(height: 16),
+            TextFormField(
+              controller: issnController,
+              decoration: InputDecoration(
+                labelText: AppLocalizations.of(context)!.issnFilter,
+                hintText: "0022-1694, 1234-5678",
+                border: OutlineInputBorder(),
+              ),
+            ),
+
             SizedBox(height: 16),
 
             DropdownButtonFormField<String>(
@@ -416,8 +473,24 @@ class OpenAlexSearchFormState extends State<OpenAlexSearchForm> {
                 ),
               ],
             ),
+            SizedBox(height: 16),
+            SwitchListTile(
+              title: Text(
+                AppLocalizations.of(context)!.openAccessOnly,
+                style: TextStyle(fontWeight: FontWeight.w500),
+              ),
+              value: _isOpenAccess,
+              onChanged: (bool value) {
+                setState(() {
+                  _isOpenAccess = value;
+                });
+              },
+            ),
+            SizedBox(height: 10),
+            Divider(
+              height: 5,
+            ),
             SizedBox(height: 10),
-
             // Dynamic query builder
             Column(
               children: () {
@@ -548,27 +621,29 @@ class OpenAlexSearchFormState extends State<OpenAlexSearchForm> {
               ],
             ),*/
             SizedBox(height: 20),
-            Text(
-              AppLocalizations.of(context)!.saveQuery,
-              style: TextStyle(fontWeight: FontWeight.bold),
-            ),
-            Switch(
+            SwitchListTile(
+              title: Text(
+                AppLocalizations.of(context)!.saveQuery,
+                style: TextStyle(fontWeight: FontWeight.w600),
+              ),
               value: saveQuery,
               onChanged: (bool value) {
                 setState(() {
                   saveQuery = value;
                 });
               },
             ),
-            SizedBox(height: 8),
-            if (saveQuery)
+            if (saveQuery) ...[
+              const SizedBox(height: 8),
               TextFormField(
                 controller: queryNameController,
                 decoration: InputDecoration(
                   labelText: AppLocalizations.of(context)!.queryName,
-                  border: OutlineInputBorder(),
+                  border: const OutlineInputBorder(),
                 ),
               ),
+            ],
+
             SizedBox(height: 70),
           ],
         ),

lib/widgets/search_query_card.dart

@@ -68,7 +68,9 @@ class SearchQueryCardState extends State<SearchQueryCard> {
         String? sortField;
         String? sortOrder;
         String? dateFilter;
+        String? issnFilter;
         String? filterValue;
+        bool isOpenAccess = false;
 
         if (widget.queryProvider == 'Crossref') {
           // Convert the params string to the needed mapstring
@@ -77,7 +79,7 @@ class SearchQueryCardState extends State<SearchQueryCard> {
           queryMap = Uri.splitQueryString(widget.queryParams);
 
           String? sortParam = queryMap['sort'];
-          String? filterValue = queryMap['filter'];
+          filterValue = queryMap['filter'];
           String? searchValue = queryMap['search'];
 
           sortField = null;
@@ -109,6 +111,10 @@ class SearchQueryCardState extends State<SearchQueryCard> {
               } else if (f.startsWith('from_publication_date:') ||
                   f.startsWith('to_publication_date:')) {
                 remainingFilters.add(f);
+              } else if (f == 'is_oa:true') {
+                isOpenAccess = true;
+              } else if (f.startsWith('locations.source.issn:')) {
+                issnFilter = f;
               }
             }
             if (remainingFilters.isNotEmpty) {
@@ -136,6 +142,8 @@ class SearchQueryCardState extends State<SearchQueryCard> {
                     'sortField': sortField,
                     'sortOrder': sortOrder,
                     'dateFilter': dateFilter,
+                    'issnFilter': issnFilter,
+                    'isOpenAccess': isOpenAccess,
                     'filter': filterValue,
                   },
                   source: widget.queryProvider,