Forum: Grouping lessons by their section on the forum post form

diff --git a/forum/forms.py b/forum/forms.py
index ec8a3be..9e931db 100644 (file)
--- a/forum/forms.py
+++ b/forum/forms.py
@@ -1,10 +1,39 @@
 from django import forms
+from django.forms.models import ModelChoiceIterator
 from django.utils.translation import ugettext as _
 import pybb.forms
 
 from catalogue.models import Lesson
 
 
+class GroupedModelChoiceIterator(ModelChoiceIterator):
+    def __init__(self, field):
+        super(GroupedModelChoiceIterator, self).__init__(field)
+        self.queryset = self.field.grouping_model.objects
+        self.items_queryset = self.field.queryset
+    
+    def choice(self, obj):
+        items_query = self.items_queryset.filter(**{self.field.grouping_fk_field: obj})
+        items = [super(GroupedModelChoiceIterator, self).choice(item) for item in items_query.all()]
+        return (unicode(obj), items)
+
+
+class GroupedModelChoiceField(forms.ModelChoiceField):
+    
+    def __init__(self, queryset, grouping_fk_field, **kwargs):
+        self.grouping_fk_field = grouping_fk_field
+        self.grouping_model = queryset.model._meta.get_field(grouping_fk_field).rel.to
+        super(GroupedModelChoiceField, self).__init__(queryset, **kwargs)
+
+    def _get_choices(self):
+        toret = super(GroupedModelChoiceField, self)._get_choices()
+        if isinstance(toret, ModelChoiceIterator):
+            toret = GroupedModelChoiceIterator(self)
+        return toret
+
+    choices = property(_get_choices, forms.ModelChoiceField.choices.fset)
+
+
 class PostForm(pybb.forms.PostForm):
-    lesson = forms.ModelChoiceField(label = _('Related lesson'), queryset = Lesson.objects.all(), required = False)
-    
\ No newline at end of file
+    lesson = GroupedModelChoiceField(label = _('Related lesson'), queryset = Lesson.objects.all(),
+        grouping_fk_field = 'section', required = False)