feat(people): Allow people to describe relationships

Creating a relationship requires answering each of the
relationship questions

resolve #2
partial #5

people/forms.py

@@ -1,7 +1,6 @@
 """
 Forms for creating / updating models belonging to the 'people' app.
 """
-
 from django import forms
 
 from . import models
@@ -17,3 +16,42 @@ class PersonForm(forms.ModelForm):
             'name',
             'core_member',
         ]
+        
+        
+class RelationshipForm(forms.ModelForm):
+    """
+    Form to allow users to describe a relationship - includes :class:`RelationshipQuestion`s.
+
+    Dynamic fields inspired by https://jacobian.org/2010/feb/28/dynamic-form-generation/
+    """
+    class Meta:
+        model = models.Relationship
+        fields = [
+            'source',
+            'target',
+        ]
+    
+    def __init__(self, *args, **kwargs):
+        super().__init__(*args, **kwargs)
+
+        for question in models.RelationshipQuestion.objects.all():
+            # Get choices from model and add default 'not selected' option
+            choices = question.choices + [['', '---------']]
+
+            field = forms.ChoiceField(label=question,
+                                      choices=choices)
+            self.fields['question_{}'.format(question.pk)] = field
+
+    def save(self, commit=True) -> models.Relationship:
+        # Save Relationship model
+        self.instance = super().save(commit=commit)
+
+        if commit:
+            # Save answers to relationship questions
+            for key, value in self.cleaned_data.items():
+                if key.startswith('question_'):
+                    question_pk = key.split('_')[-1]
+                    answer = models.RelationshipQuestionChoice.objects.get(pk=value)
+                    self.instance.question_answers.add(answer)
+
+        return self.instance