fix: trash page sorting and show more (#4967)

Author: GarvitSinghal47

contentcuration/contentcuration/frontend/channelEdit/views/trash/TrashModal.vue

@@ -201,7 +201,7 @@
         ];
       },
       items() {
-        return sortBy(this.getContentNodeChildren(this.trashId), 'modified');
+        return sortBy(this.getContentNodeChildren(this.trashId), 'modified').reverse();
       },
       backLink() {
         return {
@@ -225,9 +225,9 @@
       },
     },
     created() {
-      this.loadContentNodes({ parent__in: [this.rootId] }),
-        this.loadAncestors({ id: this.nodeId }),
-        this.loadNodes();
+      this.loadContentNodes({ parent__in: [this.rootId] });
+      this.loadAncestors({ id: this.nodeId });
+      this.loadNodes();
     },
     mounted() {
       this.updateTabTitle(this.$store.getters.appendChannelName(this.$tr('trashModalTitle')));
@@ -246,10 +246,12 @@
           this.loading = false;
           return;
         }
-        this.loadChildren({ parent: this.trashId }).then(childrenResponse => {
-          this.loading = false;
-          this.more = childrenResponse.more || null;
-        });
+        this.loadChildren({ parent: this.trashId, ordering: '-modified' }).then(
+          childrenResponse => {
+            this.loading = false;
+            this.more = childrenResponse.more || null;
+          }
+        );
       },
       moveNodes(target) {
         return this.moveContentNodes({
@@ -311,7 +313,7 @@
   };
 
 </script>
-<style lang="less" scoped>
+<style lang="scss" scoped>
 
   .show-more-button-container {
     display: flex;

contentcuration/contentcuration/frontend/channelEdit/vuex/contentNode/actions.js

@@ -71,8 +71,11 @@ export function loadContentNodeByNodeId(context, nodeId) {
     });
 }
 
-export function loadChildren(context, { parent, published = null, complete = null }) {
-  const params = { parent, max_results: 25 };
+export function loadChildren(
+  context,
+  { parent, published = null, complete = null, ordering = null }
+) {
+  const params = { parent, max_results: 25, ordering };
   if (published !== null) {
     params.published = published;
   }

contentcuration/contentcuration/frontend/shared/data/resources.js

@@ -541,6 +541,14 @@ class IndexedDBResource {
       collection = collection.filter(filterFn);
     }
     if (paginationActive) {
+      // Default pagination field is 'lft'
+      let paginationField = 'lft';
+      if (params.ordering) {
+        paginationField = params.ordering.replace(/^-/, '');
+      }
+      // Determine the operator based on the ordering direction.
+      const operator = params.ordering && params.ordering.startsWith('-') ? 'lt' : 'gt';
+
       let results;
       if (sortBy) {
         // If we still have a sortBy value here, then we have not sorted using orderBy
@@ -558,7 +566,8 @@ class IndexedDBResource {
         more: hasMore
           ? {
               ...params,
-              lft__gt: results[maxResults - 1].lft,
+              // Dynamically set the pagination cursor based on the pagination field and operator.
+              [`${paginationField}__${operator}`]: results[maxResults - 1][paginationField],
             }
           : null,
       };

contentcuration/contentcuration/viewsets/contentnode.py

@@ -669,50 +669,62 @@ def dict_if_none(obj, field_name=None):
 
 class ContentNodePagination(ValuesViewsetCursorPagination):
     """
-    A simplified cursor pagination class for ContentNodeViewSet.
-    Instead of using an opaque cursor, it uses the lft value for filtering.
-    As such, if this pagination scheme is used without applying a filter
-    that will guarantee membership to a specific MPTT tree, such as parent
-    or tree_id, the pagination scheme will not be predictable.
+    A simplified cursor pagination class
+    Instead of using a fixed 'lft' cursor, it dynamically sets the pagination field and operator
+    based on the incoming `ordering` query parameter.
     """
-    cursor_query_param = "lft__gt"
-    ordering = "lft"
     page_size_query_param = "max_results"
     max_page_size = 100
 
+    def get_pagination_params(self):
+        # Default ordering is "lft" if not provided.
+        ordering_param = self.request.query_params.get("ordering", "lft")
+        # Remove the leading '-' if present to get the field name.
+        pagination_field = ordering_param.lstrip("-")
+        # Determine operator: if ordering starts with '-', use __lt; otherwise __gt.
+        operator = "__lt" if ordering_param.startswith("-") else "__gt"
+        return pagination_field, operator
+
     def decode_cursor(self, request):
         """
-        Given a request with a cursor, return a `Cursor` instance.
+        Given a request with a cursor parameter, return a `Cursor` instance.
+        The cursor parameter name is dynamically built from the pagination field and operator.
         """
-        # Determine if we have a cursor, and if so then decode it.
-        value = request.query_params.get(self.cursor_query_param)
+        pagination_field, operator = self.get_pagination_params()
+        cursor_param = f"{pagination_field}{operator}"
+        value = request.query_params.get(cursor_param)
         if value is None:
             return None
-
-        try:
-            value = int(value)
-        except ValueError:
-            raise ValidationError("lft must be an integer but an invalid value was given.")
+        if pagination_field == "lft":
+            try:
+                value = int(value)
+            except ValueError:
+                raise ValidationError("lft must be an integer but an invalid value was given.")
 
         return Cursor(offset=0, reverse=False, position=value)
 
     def encode_cursor(self, cursor):
         """
-        Given a Cursor instance, return an url with query parameter.
+        Given a Cursor instance, return a URL with the dynamic pagination cursor query parameter.
         """
-        return replace_query_param(self.base_url, self.cursor_query_param, str(cursor.position))
+        pagination_field, operator = self.get_pagination_params()
+        cursor_param = f"{pagination_field}{operator}"
+        return replace_query_param(self.base_url, cursor_param, str(cursor.position))
 
     def get_more(self):
+        """
+        Construct a "more" URL (or query parameters) that includes the pagination cursor
+        built from the dynamic field and operator.
+        """
+        pagination_field, operator = self.get_pagination_params()
+        cursor_param = f"{pagination_field}{operator}"
         position, offset = self._get_more_position_offset()
         if position is None and offset is None:
             return None
         params = self.request.query_params.copy()
-        params.update({
-            self.cursor_query_param: position,
-        })
+        params.update({cursor_param: position})
         return params
 
-
 # Apply mixin first to override ValuesViewset
 class ContentNodeViewSet(BulkUpdateMixin, ValuesViewset):
     queryset = ContentNode.objects.all()