Custom node not receiving data from sockets

Question

Created a custom node for image modification. Cannot retrieve the image data in any way from the socket, it's always None. Do you know whats the issue here?

The code:

import bpy
class ImageModifyNode(bpy.types.Node):
    """A custom node"""
bl_idname = "ImageModifyNode"
bl_label = "Modify image"
bl_description = "Modify image by changing colors"

def init(self, context):
    self.inputs.new("NodeSocketImage", "Image")
    self.inputs.new("NodeSocketColor", "Color 1")
    self.inputs.new("NodeSocketColor", "Color 2")

    self.outputs.new("NodeSocketImage", "Image")

# Copy function to initialize a copied node from an existing one.
def copy(self, node):
    print(f"Copying from node {node}")

# Free function to clean up on removal.
def free(self):
    print(f"Removing node {self}, Goodbye!")

def socket_value_update(self, context):
    source_image = self.inputs.get("Image").default_value

    print(f"socket_value_update {source_image=}")

def update(self):
    source_image = self.inputs.get("Image").default_value
    self.outputs.get("Image").default_value = source_image

    print(f"update {source_image}")



class ImageModifyNodeAdd(bpy.types.Operator):
    """ImageModify node operator"""
bl_idname = "node.add_image_modify"
bl_label = "Add modify image node"
bl_description = "Modify image"
bl_options = {"REGISTER", "UNDO"}

def execute(self, context):
    bpy.ops.node.add_node(type=ImageModifyNode.bl_idname)

    return {"FINISHED"}

def invoke(self, context, event):
    bpy.ops.node.add_node(type=ImageModifyNode.bl_idname)

    return {"FINISHED"}



-----------------------------------------------------------------------------
Node menu list
class NodeMenu(bpy.types.Menu):
    """AI node menu container"""
bl_idname = "NODE_MT_nodes"
bl_label = "Nodes"

def draw(self, context):
    layout = self.layout

    layout.operator(ImageModifyNodeAdd.bl_idname)



def add_node_button(self, context):
    self.layout.separator()
    self.layout.menu(NodeMenu.bl_idname, icon="PLUGIN")
classes = (ImageModifyNode, ImageModifyNodeAdd, NodeMenu)
def register():
    for cls in classes:
        bpy.utils.register_class(cls)
bpy.types.NODE_MT_add.append(add_node_button)



def unregister():
    for cls in classes:
        bpy.utils.unregister_class(cls)
bpy.types.NODE_MT_add.remove(add_node_button)



if name == "main":
    register()

Expected:

Result of code:

Answer 1

For future devs experiencing issues. To get values from the parent nodes you need to navigate the node tree using links. Image will be stored not in the socket but on the node itself.

Here is an example code:

class ImageModifyNode(bpy.types.CompositorNodeImage):
"""A custom node"""
bl_idname = "ImageModifyNode"
bl_label = "Modify image"
bl_description = "Modify image by changing colors to the ones which are closest to the provided"
def init(self, context):
    self.inputs.new("NodeSocketImage", "Image")
    self.inputs.new("NodeSocketColor", "Color 1")
    self.inputs.new("NodeSocketColor", "Color 2")
self.outputs.new("NodeSocketImage", "Image")


def update(self):
    in_socket_image = self.inputs.get("Image")
    out_socket_image = self.outputs.get("Image")
if in_socket_image.is_linked:
    linked_image = in_socket_image.links[0].from_socket.node.image

    print(linked_image.pixels)