armory/blender/arm/logicnode/event/LN_on_update.py

from arm.logicnode.arm_nodes import *

class OnUpdateNode(ArmLogicTreeNode):
    """Activates the output on every frame.

    @option Update: (default) activates the output every frame.
    @option Late Update: activates the output after all non-late updates are calculated.
    @option Physics Pre-Update: activates the output before calculating the physics.
        Only available when using a physics engine."""
    bl_idname = 'LNOnUpdateNode'
    bl_label = 'On Update'
    arm_version = 1
    property0: EnumProperty(
        items = [('Update', 'Update', 'Update'),
                 ('Late Update', 'Late Update', 'Late Update'),
                 ('Physics Pre-Update', 'Physics Pre-Update', 'Physics Pre-Update')],
        name='On', default='Update')

    def init(self, context):
        super(OnUpdateNode, self).init(context)
        self.add_output('ArmNodeSocketAction', 'Out')

    def draw_buttons(self, context, layout):
        layout.prop(self, 'property0')

add_node(OnUpdateNode, category=PKG_AS_CATEGORY)