Add core utilities for views with multiple forms

gracedb/core/forms.py

@@ -40,3 +40,12 @@ class ModelFormUpdateMixin(forms.ModelForm):
         for key in self.fields.keys():
             if not self.data.has_key(key) and instance_data[key]:
                 self.data[key] = instance_data[key]
+
+
+class MultipleForm(forms.Form):
+    key = None
+    key_field = forms.CharField(max_length=30, widget=forms.HiddenInput())
+
+    def __init__(self, *args, **kwargs):
+        super(MultipleForm, self).__init__(*args, **kwargs)
+        self.fields['key_field'].initial = self.key

gracedb/core/views.py

 from django.http import HttpResponse
+from django.views.generic.edit import FormView
 
-def heartbeat(request):
+import logging
+logger = logging.getLogger(__name__)
 
+def heartbeat(request):
     # Do something (?) and return 200 response
     return HttpResponse()
+
+
+class MultipleFormView(FormView):
+    """Requires forms to inherit from core.forms.MultipleForm"""
+    form_classes = []
+
+    @property
+    def form_classes(self):
+        if not hasattr(self, '_form_classes'):
+            self._form_classes = {f.key: f for f in self.form_class_list}
+        return self._form_classes
+
+    def get_forms(self, form_classes=None):
+        if (form_classes is None):
+            form_classes = self.form_classes
+        return [form(**self.get_form_kwargs(form.key)) for form in form_classes]
+
+    def get_form_kwargs(self, form_key):
+        kwargs = {
+            'initial': self.get_initial(),
+            'prefix': self.get_prefix(),
+        }
+        if (self.request.method in ('POST', 'PUT')):
+            key_field = self.request.POST.get('key_field', None)
+            if (key_field is not None and key_field == form_key):
+                kwargs.update({'data': self.request.POST,
+                    'files': self.request.FILES})
+        return kwargs
+
+    def get(self, request, *args, **kwargs):
+        forms = self.get_forms()
+        return self.render_to_response(self.get_context_data(forms=forms))
+
+    def post(self, request, *args, **kwargs):
+        form_key = request.POST.get('key_field')
+        forms = self.get_forms()
+        return self._process_individual_form(form_key, forms)
+
+    def forms_valid(self, form):
+        form_valid_method = '{key}_form_valid'.format(key=form.key)
+        if hasattr(self, form_valid_method):
+            return getattr(self, form_valid_method)(form)
+        else:
+            return HttpResponseRedirect(self.success_url)
+
+    def forms_invalid(self, forms):
+        return self.render_to_response(self.get_context_data(forms=forms))
+
+    def _get_form_by_key(self, key, forms):
+        form_keys = [f.key for f in forms]
+        return forms[form_keys.index(key)]
+
+    def _process_individual_form(self, form_key, forms):
+        form = self._get_form_by_key(form_key, forms)
+        if form.is_valid():
+            return self.forms_valid(form)
+        else:
+            return self.forms_invalid(forms)