performance optimization to get full learningpath content

scripts/count_queries.py

@@ -0,0 +1,34 @@
+# -*- coding: utf-8 -*-
+import json
+import os
+import sys
+
+import django
+
+sys.path.append("../server")
+
+os.environ.setdefault("IT_APP_ENVIRONMENT", "development")
+os.environ.setdefault("DJANGO_SETTINGS_MODULE", "config.settings.base")
+django.setup()
+
+from vbv_lernwelt.learnpath.models import LearningPath
+from vbv_lernwelt.learnpath.serializers import LearningPathSerializer
+
+
+def main():
+    from django.conf import settings
+    settings.DEBUG = True
+    from django.db import connection
+    from django.db import reset_queries
+    reset_queries()
+
+    learning_path = LearningPath.objects.filter(slug='versicherungsvermittlerin', locale__language_code='de-CH').first()
+
+    serializer = LearningPathSerializer(learning_path)
+    print(serializer.data)
+    print(len(json.dumps(serializer.data)))
+    print(len(connection.queries))
+
+
+if __name__ == '__main__':
+    main()

server/vbv_lernwelt/learnpath/models.py

@@ -55,8 +55,9 @@ class Topic(Page):
 
     @classmethod
     def get_serializer_class(cls):
-        return get_it_serializer_class(cls,
-                                       field_names=['id', 'title', 'slug', 'type', 'translation_key', 'is_visible', ])
+        return get_it_serializer_class(
+            cls, field_names=['id', 'title', 'slug', 'type', 'translation_key', 'is_visible', ]
+        )
 
     class Meta:
         verbose_name = "Topic"

server/vbv_lernwelt/learnpath/serializer_helpers.py

@@ -20,5 +20,21 @@ class ItBaseSerializer(wagtail_serializers.BaseSerializer):
 
     meta_fields = []
 
+    def __init__(self, *args, **kwargs):
+        self.descendants = kwargs.pop('descendants', None)
+        super().__init__(*args, **kwargs)
+
     def get_children(self, obj):
-        return [c.specific.get_serializer_class()(c.specific).data for c in obj.get_children()]
+        if self.descendants:
+            children = _get_children(self.descendants, obj)
+            return [c.specific.get_serializer_class()(c.specific, descendants=self.descendants).data for c in children]
+        else:
+            return [c.specific.get_serializer_class()(c.specific).data for c in obj.get_children().specific()]
+
+
+def _get_descendants(pages, obj):
+    return [c for c in pages if c.path.startswith(obj.path) and c.depth >= obj.depth]
+
+
+def _get_children(pages, obj):
+    return [c for c in pages if c.path.startswith(obj.path) and obj.depth + 1 == c.depth]

server/vbv_lernwelt/learnpath/serializers.py

@@ -1,7 +1,7 @@
 from rest_framework import serializers
 
 from vbv_lernwelt.learnpath.models import Circle, LearningPath
-from vbv_lernwelt.learnpath.serializer_helpers import get_it_serializer_class
+from vbv_lernwelt.learnpath.serializer_helpers import get_it_serializer_class, _get_children
 
 
 class LearningPathSerializer(get_it_serializer_class(LearningPath, [])):
@@ -10,7 +10,8 @@ class LearningPathSerializer(get_it_serializer_class(LearningPath, [])):
     meta_fields = []
 
     def get_children(self, obj):
-        return [c.specific.get_serializer_class()(c.specific).data for c in obj.get_children()]
+        descendants = [p for p in obj.get_descendants().specific()]
+        return [c.specific.get_serializer_class()(c.specific, descendants=descendants).data for c in _get_children(descendants, obj)]
 
     def get_meta_label(self, obj):
         return obj._meta.label