Select Circle expert/trainer on the admin field (not dynamic)

server/vbv_lernwelt/course/admin.py

@@ -1,6 +1,7 @@
 from django.contrib import admin
 
 from vbv_lernwelt.course.models import CourseSession, CourseSessionUser
+from vbv_lernwelt.learnpath.models import Circle
 
 
 @admin.register(CourseSession)
@@ -35,3 +36,26 @@ class CourseSessionUserAdmin(admin.ModelAdmin):
         "course_session__course",
         "course_session",
     ]
+
+    fieldsets = [
+        (None, {"fields": ("user", "course_session")}),
+        (
+            "Expert/Trainer",
+            {
+                "fields": ("expert",),
+                "description": "Expert/Trainer kann erst ausgewählt werden, wenn der Kurs ausgewählt und bereits einmal gespeichert wurde.",
+            },
+        ),
+    ]
+
+    def formfield_for_manytomany(self, db_field, request, **kwargs):
+        if db_field.name == "expert":
+            if request.resolver_match.kwargs.get("object_id"):
+                object_id = int(request.resolver_match.kwargs.get("object_id"))
+                csu = CourseSessionUser.objects.get(id=object_id)
+                kwargs["queryset"] = Circle.objects.descendant_of(
+                    csu.course_session.course.coursepage
+                )
+            else:
+                kwargs["queryset"] = Circle.objects.none()
+        return super().formfield_for_manytomany(db_field, request, **kwargs)

server/vbv_lernwelt/course/migrations/0004_coursesessionuser_expert.py

@@ -0,0 +1,19 @@
+# Generated by Django 3.2.13 on 2022-11-07 15:51
+
+from django.db import migrations, models
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ('learnpath', '0008_alter_learningcontent_contents'),
+        ('course', '0003_alter_coursepage_course'),
+    ]
+
+    operations = [
+        migrations.AddField(
+            model_name='coursesessionuser',
+            name='expert',
+            field=models.ManyToManyField(related_name='expert', to='learnpath.Circle'),
+        ),
+    ]

server/vbv_lernwelt/course/migrations/0005_alter_coursesessionuser_expert.py

@@ -0,0 +1,19 @@
+# Generated by Django 3.2.13 on 2022-11-07 15:53
+
+from django.db import migrations, models
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ('learnpath', '0008_alter_learningcontent_contents'),
+        ('course', '0004_coursesessionuser_expert'),
+    ]
+
+    operations = [
+        migrations.AlterField(
+            model_name='coursesessionuser',
+            name='expert',
+            field=models.ManyToManyField(blank=True, related_name='expert', to='learnpath.Circle'),
+        ),
+    ]

server/vbv_lernwelt/course/models.py

@@ -197,6 +197,10 @@ class CourseSessionUser(models.Model):
     course_session = models.ForeignKey("course.CourseSession", on_delete=models.CASCADE)
     user = models.ForeignKey(User, on_delete=models.CASCADE)
 
+    expert = models.ManyToManyField(
+        "learnpath.Circle", related_name="expert", blank=True
+    )
+
     class Meta:
         constraints = [
             UniqueConstraint(

server/vbv_lernwelt/course/permissions.py

@@ -29,6 +29,6 @@ def course_sessions_for_user_qs(user):
 
     course_sessions = CourseSession.objects.filter(
         course_session_user__user=user
-    ).distinct()
+    ).select_related("coursesessionuser")
 
     return course_sessions

server/vbv_lernwelt/course/serializers.py

@@ -5,7 +5,9 @@ from vbv_lernwelt.course.models import (
     CourseCategory,
     CourseCompletion,
     CourseSession,
+    CourseSessionUser,
 )
+from vbv_lernwelt.learnpath.models import Circle
 
 
 class CourseSerializer(serializers.ModelSerializer):
@@ -46,6 +48,7 @@ class CourseSessionSerializer(serializers.ModelSerializer):
     competence_url = serializers.SerializerMethodField()
     media_library_url = serializers.SerializerMethodField()
     course = serializers.SerializerMethodField()
+    experts = serializers.SerializerMethodField()
 
     def get_course(self, obj):
         return CourseSerializer(obj.course).data
@@ -59,6 +62,22 @@ class CourseSessionSerializer(serializers.ModelSerializer):
     def get_competence_url(self, obj):
         return obj.course.get_competence_url()
 
+    def get_experts(self, obj):
+        expert_relations = CourseSessionUser.objects.filter(
+            expert__in=Circle.objects.descendant_of(obj.course.coursepage)
+        )
+        expert_result = []
+        for er in expert_relations:
+            for circle in er.expert.all():
+                expert_result.append(
+                    {
+                        "user_id": er.user.id,
+                        "circle_id": circle.id,
+                        "circle_translation_key": circle.translation_key,
+                    }
+                )
+        return expert_result
+
     class Meta:
         model = CourseSession
         fields = [
@@ -73,4 +92,5 @@ class CourseSessionSerializer(serializers.ModelSerializer):
             "learning_path_url",
             "competence_url",
             "media_library_url",
+            "experts",
         ]