Select a default form type dynamically for form generation

This sets up the main form generation form to pick a default form type
dynamically when rendering the form. If there is more than one form type
available to the person generating the form no default is returned,
forcing them to actively select one. But if they only have one type
available to them that type is set as the default to save them a click.
This was motivated by the need to allow embedded companies to generate
registration forms for their staff, but they should only be allowed to
generate 'visitor' forms. It therefore makes no sense to make them click
to pick that option.

chemistry_starters/forms/form_generation.py

@@ -7,6 +7,7 @@ from wtforms import BooleanField, IntegerField, RadioField, TextAreaField, valid
 
 from chemistry_starters.forms.widgets import StrippedStringField
 from chemistry_starters.roles import roles
+from chemistry_starters.utils.form_generation import get_form_type_default
 
 form_types = [(x, roles[x]["form_title"]) for x in roles]
 
@@ -17,7 +18,10 @@ class GenerateFormsForm(FlaskForm):
     """
 
     form_type = RadioField(
-        "Type of form to generate", [validators.InputRequired()], choices=form_types
+        "Type of form to generate",
+        [validators.InputRequired()],
+        choices=form_types,
+        default=get_form_type_default,
     )
     starter_email = StrippedStringField(
         "Contact email address for starter", [validators.Optional(), validators.Email()]

chemistry_starters/utils/form_generation.py

 """
 Helper functions for the form generation views
 """
+from flask import g
 
 from chemistry_starters import database
 from chemistry_starters.forms import form_generation as forms
@@ -36,3 +37,17 @@ def is_form_imported(uuid):
     """
     import_date = database.get_form_column("_imported_on", uuid)
     return import_date is not None
+
+
+def get_form_type_default():
+    """
+    Get the default form type
+
+    Usually there is no default type, but if the person only has one form type
+    available, return that
+    """
+    form_types = database.form_types_for_person(g.crsid)
+    if len(form_types) == 1:
+        return form_types[0]
+    else:
+        return None