rearange driver variable, fcurve setup

This commit rearranges some steps in driver setup
so that more properties will be available earlier
the goal and the intention of this change is to make it possible
for me to determine exactly what a driver value is before it first
updates so that I can set driver defaults in places where it affects
the start pose of the rig etc

specifically for curve pin, which is the only place I really need this

misc_nodes.py

@@ -798,9 +798,12 @@ class UtilityDriverVariable(MantisMiscNode):
 
     def reset_execution(self):
         super().reset_execution()
-        # clear this to ensure there are no stale reference pointers
-        self.parameters["Driver Variable"] = None
-        self.prepared=True
+        # clear the pointer properties to prevent using stale pointer data.
+        my_var = self.parameters["Driver Variable"]
+        if my_var is not None:
+            my_var["owner"]   = xForm1 # will be filled in by Driver
+            my_var["xForm 1"] = xForm1 # self.GetxForm(index = 1),
+            my_var["xForm 2"] = xForm2 # self.GetxForm(index = 2),
 
     # NOTE _index for interface consistency
     def evaluate_input(self, input_name, _index=0):
@@ -821,16 +824,7 @@ class UtilityDriverVariable(MantisMiscNode):
                 return node #this will fetch the first one, that's good!
         return None
 
-    def bRelationshipPass(self, bContext = None,):
-        prepare_parameters(self)
-        #prPurple ("Executing Driver Variable Node")
-        xF1 = self.GetxForm()
-        xF2 = self.GetxForm(index=2)
-        # kinda clumsy
-        xForm1, xForm2 = None, None
-        if xF1 : xForm1 = xF1.bGetObject()
-        if xF2 : xForm2 = xF2.bGetObject()
-
+    def bPrepare(self, bContext=None):
         v_type = self.evaluate_input("Variable Type")
         i = self.evaluate_input("Property Index"); dVarChannel = ""
         if not isinstance(i, (int, float)):
@@ -858,17 +852,32 @@ class UtilityDriverVariable(MantisMiscNode):
         if dVarChannel: v_type = "TRANSFORMS"
 
         my_var = {
-            "owner"         : xForm1, # will be filled in by Driver
+            "owner"         : None,
             "prop"          : self.evaluate_input("Property"), # will be filled in by Driver
             "type"          : v_type,
             "space"         : self.evaluate_input("Evaluation Space"),
             "rotation_mode" : self.evaluate_input("Rotation Mode"),
-            "xForm 1"       : xForm1,#self.GetxForm(index = 1),
-            "xForm 2"       : xForm2,#self.GetxForm(index = 2),
+            "xForm 1"       : None, # not available yet
+            "xForm 2"       : None, # not available yet
             "channel"       : dVarChannel,}
 
         self.parameters["Driver Variable"] = my_var
-        print (my_var['prop'])
+        self.prepared = True
+        
+
+    def bRelationshipPass(self, bContext = None,):
+        prepare_parameters(self)
+        xF1 = self.GetxForm(index = 1)
+        xF2 = self.GetxForm(index = 2)
+        # kinda clumsy
+        xForm1, xForm2 = None, None
+        if xF1 : xForm1 = xF1.bGetObject()
+        if xF2 : xForm2 = xF2.bGetObject()
+        my_var = self.parameters["Driver Variable"]
+        if my_var is not None:
+            my_var["owner"]   = xForm1 # will be filled in by Driver
+            my_var["xForm 1"] = xForm1 # self.GetxForm(index = 1),
+            my_var["xForm 2"] = xForm2 # self.GetxForm(index = 2),
         self.executed = True
 
 class UtilityKeyframe(MantisMiscNode):
@@ -899,16 +908,11 @@ class UtilityFCurve(MantisMiscNode):
     __slots__ = ()
     socket_templates = FCurveSockets
 
-    def __init__(self, signature, base_tree):
-        super().__init__(signature, base_tree, self.socket_templates)
-        self.prepared = True
 
     def reset_execution(self):
         super().reset_execution()
-        self.prepared=True
 
-    def bTransformPass(self, bContext = None,):
-        prepare_parameters(self)
+    def bPrepare(self, bContext = None,):
         extrap_mode = self.evaluate_input("Extrapolation Mode")
         keys = []
         for i in range(len(self.inputs['Keyframes'].links)):
@@ -917,7 +921,9 @@ class UtilityFCurve(MantisMiscNode):
             prOrange(f"WARN: no keys in fCurve {self}.")
         keys.append(extrap_mode)
         self.parameters["fCurve"] = keys
+        self.prepared = True
         self.executed = True
+
 #TODO make the keyframe, fCurve data classes instead of dicts!
 
 class UtilityDriver(MantisMiscNode):