feat(projects): add method to find next relevant page #1191

Signed-off-by: David Wallace <[email protected]>

rdmo/projects/progress.py

@@ -47,6 +47,48 @@ def compute_sets(values):
     return sets
 
 
+def compute_next_relevant_page(current_page, direction, catalog, resolved_conditions):
+    # compute the next relevant page based on resolved conditions.
+    max_iterations = len(catalog.pages)
+    iterations = 0
+
+    while iterations < max_iterations:
+        iterations += 1
+
+        # Determine the next page based on the specified direction
+        next_page = (catalog.get_prev_page(current_page) if direction == 'prev'
+                     else catalog.get_next_page(current_page))
+
+        # If no further pages are available, return None
+        if not next_page:
+            return None
+
+        # Use compute_show_page with precomputed resolved_conditions to check if the next page meets conditions
+        if compute_show_page(next_page, resolved_conditions):
+            return next_page  # Found the next relevant page
+
+        # Move to the next page in sequence if conditions are not met
+        current_page = next_page
+    return None
+
+def compute_show_page(page, conditions):
+    """Determine if a page should be shown based on resolved conditions."""
+    # show only pages with resolved conditions, but show all pages without conditions
+    pages_conditions = {page.id for page in page.conditions.all()}
+
+    if pages_conditions:
+        # check if any valuesets for set_prefix = '' resolved
+        # for non collection pages restrict further to set_index = 0
+
+        return any(
+            (set_prefix == '') and (page.is_collection or set_index == 0)
+            for page_condition in pages_conditions
+            for set_prefix, set_index in conditions[page_condition]
+        )
+    else:
+        return True
+
+
 def compute_navigation(section, project, snapshot=None):
     # get all values for this project and snapshot
     values = project.values.filter(snapshot=snapshot).select_related('attribute', 'option')
@@ -74,19 +116,8 @@ def compute_navigation(section, project, snapshot=None):
             navigation_section['pages'] = []
 
         for page in catalog_section.elements:
-            pages_conditions = {page.id for page in page.conditions.all()}
-
-            # show only pages with resolved conditions, but show all pages without conditions
-            if pages_conditions:
-                # check if any valuesets for set_prefix = '' resolved
-                # for non collection pages restrict further to set_index = 0
-                show = any(
-                    (set_prefix == '') and (page.is_collection or set_index == 0)
-                    for page_condition in pages_conditions
-                    for set_prefix, set_index in conditions[page_condition]
-                )
-            else:
-                show = True
+
+            show = compute_show_page(page, conditions)
 
             # count the total number of questions, taking sets and conditions into account
             counts = count_questions(page, sets, conditions)

rdmo/projects/viewsets.py

@@ -42,7 +42,14 @@
     HasProjectProgressObjectPermission,
     HasProjectsPermission,
 )
-from .progress import compute_navigation, compute_progress
+from .progress import (
+    compute_navigation,
+    compute_next_relevant_page,
+    compute_progress,
+    compute_sets,
+    compute_show_page,
+    resolve_conditions,
+)
 from .serializers.v1 import (
     IntegrationSerializer,
     InviteSerializer,
@@ -521,29 +528,33 @@ def dispatch(self, *args, **kwargs):
 
     def retrieve(self, request, *args, **kwargs):
         page = self.get_object()
-        conditions = page.conditions.select_related('source', 'target_option')
-
+        catalog = self.project.catalog
         values = self.project.values.filter(snapshot=None).select_related('attribute', 'option')
 
-        if check_conditions(conditions, values):
+        sets = compute_sets(values)
+        resolved_conditions = resolve_conditions(catalog, values, sets)
+
+        # check if the current page meets conditions
+        if compute_show_page(page, resolved_conditions):
             serializer = self.get_serializer(page)
             return Response(serializer.data)
         else:
-            if request.GET.get('back') == 'true':
-                prev_page = self.project.catalog.get_prev_page(page)
-                if prev_page is not None:
-                    url = reverse('v1-projects:project-page-detail',
-                                  args=[self.project.id, prev_page.id]) + '?back=true'
-                    return HttpResponseRedirect(url, status=303)
-            else:
-                next_page = self.project.catalog.get_next_page(page)
-                if next_page is not None:
-                    url = reverse('v1-projects:project-page-detail', args=[self.project.id, next_page.id])
-                    return HttpResponseRedirect(url, status=303)
-
-            # indicate end of catalog
+            # determine the direction of navigation (previous or next)
+            direction = 'prev' if request.GET.get('back') == 'true' else 'next'
+
+            # find the next relevant page with from pages and resolved conditions
+            next_page = compute_next_relevant_page(page, direction, catalog, resolved_conditions)
+
+            if next_page is not None:
+                url = reverse('v1-projects:project-page-detail', args=[self.project.id, next_page.id])
+                if direction == 'prev':
+                    url += '?back=true'
+                return HttpResponseRedirect(url, status=303)
+
+            # end of catalog, if no next relevant page is found
             return Response(status=204)
 
+
     @action(detail=False, url_path='continue', permission_classes=(HasModelPermission | HasProjectPagePermission, ))
     def get_continue(self, request, pk=None, parent_lookup_project=None):
         try: