Validation on number of inputs added

system/workflow.py

@@ -114,12 +114,19 @@ class Function:
         self.id = id
         self.name = name
 
-    def valid_input(input):
-        return True
+    # ,ust return a Validation object
+    def validate_input(input):
+        return Validation(True,"Validation Not Implemented")
 
-    def run(self, data):
+    def run(self):
         pass
 
+class Validation:
+    def __init__(self,result, reason):
+        self.succeeded = result
+        self.reason = reason
+
+
 class WorkflowView (gtk.VBox):
    
     def __init__(self, wf):
@@ -162,10 +169,25 @@ class WorkflowView (gtk.VBox):
         project = self.workflow.app.project
         parent_data = project.current_data
 
-        new_data = function.run(project.current_data)
+        validation  = function.validate_input()
+
+        if not validation.succeeded:
+            logger.log('warning','Invalid Inputdata: ' + str(reason))
+            return
+        
+        argcount =function.run.func_code.co_argcount - 1
+        
+        if  argcount != len(parent_data):
+            logger.log('warning','Method requires ' + str(argcount) + ' Data. ' + str(len(parent_data)) + ' selected')
+            return
+        if not project.current_data:
+            new_data = function.run()
+        else:
+            new_data = function.run(*project.current_data)
+
         if new_data != None:
             project.add_data(parent_data, new_data, function.name)
-
+        
         logger.log('debug', 'Function ended: %s' % function.name)
         
     def button_click_handler(self, button):