Use the recently added information about if a parameter is required f…

…or asking only for the not initialized parameters when loading a parameterized workspace. See Wirecloud#291

src/wirecloud/platform/preferences/views.py

@@ -159,6 +159,7 @@ def update_workspace_preferences(workspace, preferences_json, invalidate_cache=T
             preference = currentPreferences[name]
         else:
             preference = WorkspacePreference(workspace=workspace, name=name)
+            changes = pref_changes = True
 
         if isinstance(preference_data, dict):
             if 'value' in preference_data and preference.value != preference_data['value']:

src/wirecloud/platform/workspace/mashupTemplateParser.py

@@ -202,6 +202,7 @@ def fillWorkspaceUsingTemplate(workspace, template):
             'inheritable': False,
             'label': param.get('label'),
             'type': param.get('type'),
+            'required': param.get('required')
         })
 
     for tab_entry in mashup_description['tabs']:

src/wirecloud/platform/workspace/utils.py

@@ -395,7 +395,7 @@ def process_forced_values(workspace, user, concept_values, preferences):
     param_values = {}
     empty_params = []
     for param in forced_values['extra_prefs']:
-        if param['name'] in preferences:
+        if param['name'] in preferences and (param['required'] is False or preferences[param['name']]['value'].strip() != ''):
             param_values[param['name']] = preferences[param['name']]['value']
         else:
             empty_params.append(param['name'])