add fields limit option to posts

Author: yringler

lib/requests/params_post_list.dart

@@ -25,7 +25,8 @@ class ParamsPostList {
   final List<int> includeTags;
   final List<int> excludeTags;
   final bool? sticky;
-
+  /// Which fields to retrieve. If empty, gets all fields.
+  final List<String> fields;
   ParamsPostList({
     this.context = WordPressContext.view,
     this.pageNum = 1,
@@ -47,6 +48,7 @@ class ParamsPostList {
     this.includeTags = const [],
     this.excludeTags = const [],
     this.sticky,
+    this.fields = const []
   });
 
   Map<String, String> toMap() {
@@ -71,36 +73,37 @@ class ParamsPostList {
       'tags': '${listToUrlString(includeTags)}',
       'tags_exclude': '${listToUrlString(excludeTags)}',
       'sticky': '${this.sticky == null ? '' : this.sticky}',
+      '_fields': this.fields.join(','),
     };
   }
 
-ParamsPostList copyWith({
-  int? pageNum,
-  int? perPage,
-}) {
-  return ParamsPostList(
-    afterDate: afterDate,
-    beforeDate: beforeDate,
-    context: context,
-    excludeAuthorIDs: excludeAuthorIDs,
-    excludeCategories: excludeCategories,
-    excludePostIDs: excludePostIDs,
-    excludeTags: excludeTags,
-    includeAuthorIDs: includeAuthorIDs,
-    includeCategories: includeCategories,
-    includePostIDs: includePostIDs,
-    includeTags: includeTags,
-    offset: offset,
-    order: order,
-    orderBy: orderBy,
-    pageNum: pageNum ?? this.pageNum,
-    perPage: perPage ?? this.perPage,
-    postStatus: postStatus,
-    searchQuery: searchQuery,
-    slug: slug,
-    sticky: sticky
-  );
-}
+  ParamsPostList copyWith({
+    int? pageNum,
+    int? perPage,
+  }) {
+    return ParamsPostList(
+        afterDate: afterDate,
+        beforeDate: beforeDate,
+        context: context,
+        excludeAuthorIDs: excludeAuthorIDs,
+        excludeCategories: excludeCategories,
+        excludePostIDs: excludePostIDs,
+        excludeTags: excludeTags,
+        includeAuthorIDs: includeAuthorIDs,
+        includeCategories: includeCategories,
+        includePostIDs: includePostIDs,
+        includeTags: includeTags,
+        offset: offset,
+        order: order,
+        orderBy: orderBy,
+        pageNum: pageNum ?? this.pageNum,
+        perPage: perPage ?? this.perPage,
+        postStatus: postStatus,
+        searchQuery: searchQuery,
+        slug: slug,
+        sticky: sticky,
+        fields: fields);
+  }
 
   @override
   String toString() {