#46 MIME Type check

* adds file mime type check on NewDocumentForm
* adds file size check on NewDocumentForm
* adds is_xy_valid methods as classmethods on AbstractDocument
* adds translations for error messages
* updates help text on NewDocumentForm file field

konova/forms.py

@@ -354,7 +354,7 @@ class NewDocumentForm(BaseModalForm):
     file = forms.FileField(
         label=_("File"),
         label_suffix=_(""),
-        help_text=_("Must be smaller than 15 Mb"),
+        help_text=_("Allowed formats: pdf, jpg, png. Max size 15 MB."),
         widget=forms.FileInput(
             attrs={
                 "class": "form-control-file",
@@ -391,6 +391,28 @@ class NewDocumentForm(BaseModalForm):
         if not self.document_model:
             raise NotImplementedError("Unsupported document type for {}".format(self.instance.__class__))
 
+    def is_valid(self):
+        super_valid = super().is_valid()
+
+        _file = self.cleaned_data.get("file", None)
+
+        mime_type_valid = self.document_model.is_mime_type_valid(_file)
+        if not mime_type_valid:
+            self.add_error(
+                "file",
+                _("Unsupported file type")
+            )
+
+        file_size_valid = self.document_model.is_file_size_valid(_file)
+        if not file_size_valid:
+            self.add_error(
+                "file",
+                _("File too large")
+            )
+
+        file_valid = mime_type_valid and file_size_valid
+        return super_valid and file_valid
+
     def save(self):
         with transaction.atomic():
             action = UserActionLogEntry.get_created_action(self.user)