Merge pull request #4118 from nortikin/node_groups_to_json

New structure for JSON files and new approach of adding changes into the JSON format

core/monad.py

@@ -91,7 +91,7 @@ def monad_make_unique(node):
 
     # the new tree dict will contain information about 1 node only, and 
     # the node_group too (at the moment) but the node_group data can be ignored.
-    layout_json = JSONExporter.get_nodes_structure([node])
+    layout_json = JSONExporter._get_nodes_structure([node])
 
     # do not restore links this way. wipe this entry and restore at a later stage.
     layout_json['update_lists'] = []

core/node_group.py

@@ -32,12 +32,17 @@ class SvGroupTree(bpy.types.NodeTree):
 
     handler = MainHandler
 
-    group_node_name: bpy.props.StringProperty()  # should be updated by "Go to edit group tree" operator
-    tree_id_memory: bpy.props.StringProperty(default="")  # identifier of the tree, should be used via `tree_id`
-    skip_tree_update: bpy.props.BoolProperty()  # useless for API consistency # todo should be removed later
+    # should be updated by "Go to edit group tree" operator
+    group_node_name: bpy.props.StringProperty(options={'SKIP_SAVE'})
+
+    # identifier of the tree, should be used via `tree_id`
+    tree_id_memory: bpy.props.StringProperty(default="", options={'SKIP_SAVE'})
+
+    # useless for API consistency # todo should be removed later
+    skip_tree_update: bpy.props.BoolProperty(options={'SKIP_SAVE'})
 
     # Always False, does not have sense to have for nested trees, sine of draft mode refactoring
-    sv_draft: bpy.props.BoolProperty()
+    sv_draft: bpy.props.BoolProperty(options={'SKIP_SAVE'})
 
     @property
     def tree_id(self):
@@ -95,6 +100,9 @@ def can_be_linked(self):
     def update(self):
         """trigger on links or nodes collections changes, on assigning tree to a group node"""
         # When group input or output nodes are connected some extra work should be done
+        if 'init_tree' in self.id_data:  # tree is building by a script - let it do this
+            return
+
         self.check_last_socket()  # Should not be too expensive to call it each update
 
         if self.name not in bpy.data.node_groups:  # load new file event
@@ -197,6 +205,11 @@ def update_nodes(self, nodes: list):
         1. Node property of was changed
         2. ???
         """
+        # the method can be called during tree reconstruction from JSON file
+        # in this case we does not intend doing any updates
+        if not self.group_node_name:  # initialization tree
+            return
+
         self.handler.send(GroupEvent(GroupEvent.NODES_UPDATE, self.get_update_path(), updated_nodes=nodes))
 
     def parent_nodes(self) -> Iterator['SvGroupTreeNode']:
@@ -240,6 +253,20 @@ def throttle_update(self):
         """useless, for API consistency here"""
         yield self
 
+    @contextmanager
+    def init_tree(self):
+        """It suppresses calling the update method of nodes,
+        main usage of it is during generating tree with python (JSON import)"""
+        is_already_initializing = 'init_tree' in self
+        if is_already_initializing:
+            yield self
+        else:
+            self['init_tree'] = ''
+            try:
+                yield self
+            finally:
+                del self['init_tree']
+
     def get_update_path(self) -> List['SvGroupTreeNode']:
         """
         Should be called only during tree or node update events
@@ -416,6 +443,9 @@ def active_input(self) -> Optional[bpy.types.Node]:
                 return node
 
     def update(self):
+        if 'init_tree' in self.id_data:  # tree is building by a script - let it do this
+            return
+
         # this code should work only first time a socket was added
         if self.node_tree:
             for n_in_s, t_in_s in zip(self.inputs, self.node_tree.inputs):

core/sockets.py

@@ -55,13 +55,16 @@
 
 def process_from_socket(self, context):
     """Update function of exposed properties in Sockets"""
-    self.node.process_node(context)
+    if self.node is not None:  # https://developer.blender.org/T88587
+        self.node.process_node(context)
 
 
 def update_interface(self, context):
     """Update group node sockets and update it"""
     # For now I don't think that `hide value` property should call this function, but in some cases it could be useful
     # if interface socket will get min and max value parameter then probably Sv sockets also should get it
+    if not self.id_data.group_node_name:  # initialization tree
+        return
     self.id_data.update_sockets()
     group_tree = self.id_data
     group_node = group_tree.get_update_path()[-1]
@@ -313,15 +316,13 @@ class SvSocketCommon(SvSocketProcessing):
     color = (1, 0, 0, 1)  # base color, other sockets should override the property, use FloatProperty for dynamic
     label: StringProperty()  # It will be drawn instead of name if given
     quick_link_to_node = str()  # sockets which often used with other nodes can fill its `bl_idname` here
-    link_menu_handler : StringProperty(default='', options={'SKIP_SAVE'}) # To specify additional entries in the socket link menu
-    enable_input_link_menu : BoolProperty(default = True, options={'SKIP_SAVE'})
+    link_menu_handler : StringProperty(default='') # To specify additional entries in the socket link menu
+    enable_input_link_menu : BoolProperty(default = True)
 
     # set True to use default socket property if it has got it
-    use_prop: BoolProperty(default=False, options={'SKIP_SAVE'})
-    custom_draw: StringProperty(description="For name of method which will draw socket UI (optionally)",
-                                options={'SKIP_SAVE'})
-    prop_name: StringProperty(default='', description="For displaying node property in socket UI",
-                              options={'SKIP_SAVE'})
+    use_prop: BoolProperty(default=False)
+    custom_draw: StringProperty(description="For name of method which will draw socket UI (optionally)")
+    prop_name: StringProperty(default='', description="For displaying node property in socket UI")
 
     # utility field for showing number of objects in sockets data
     objects_number: IntProperty(min=0, options={'SKIP_SAVE'})
@@ -598,7 +599,7 @@ def filter_kinds(self, objs):
             return True
 
     color = (0.69, 0.74, 0.73, 1.0)
-    use_prop: BoolProperty(default=True, options={'SKIP_SAVE'})
+    use_prop: BoolProperty(default=True)
 
     object_kinds: StringProperty(default='ALL')  # use for filtering objects, see filter_kinds method
     object_ref: StringProperty(update=process_from_socket)
@@ -894,7 +895,7 @@ def get_prop_data(self):
         else:
             return {}
 
-    quick_link_to_node: StringProperty(options={'SKIP_SAVE'})  # this can be overridden by socket instances
+    quick_link_to_node: StringProperty()  # this can be overridden by socket instances
 
     default_property_type: bpy.props.EnumProperty(items=[(i, i, '') for i in ['float', 'int']])
     default_float_property: bpy.props.FloatProperty(update=process_from_socket)