[Heat] Fix default values displaying for "Launch Stack"

This patch set fixes default values displaying for JSON parameters
to make it possible to use them without any changes.

Closes-Bug: #1438138

Change-Id: Ib925dc39320f7cab240eed3ccbcf1fa574bc5507

openstack_dashboard/dashboards/project/stacks/forms.py

@@ -327,6 +327,10 @@ class CreateStackForm(forms.SelfHandlingForm):
                 field_args['choices'] = choices
                 field = forms.ChoiceField(**field_args)
 
+            elif param_type == 'Json' and 'Default' in param:
+                field_args['initial'] = json.dumps(param['Default'])
+                field = forms.CharField(**field_args)
+
             elif param_type in ('CommaDelimitedList', 'String', 'Json'):
                 if 'MinLength' in param:
                     field_args['min_length'] = int(param['MinLength'])

tox.ini

@@ -60,7 +60,7 @@ downloadcache = ~/cache/pip
 exclude = .venv,.git,.tox,dist,*openstack/common*,*lib/python*,*egg,build,panel_template,dash_template,local_settings.py,*/local/*,*/test/test_plugins/*,.ropeproject
 # H405 multi line docstring summary not separated with an empty line
 ignore = H405
-max-complexity = 19
+max-complexity = 20
 
 [hacking]
 import_exceptions = collections.defaultdict,