pythonpart-script

name	pythonpart-script
description	Use this skill when writing python code for a PythonPart. It covers the structure of the script, the Script Object contract, coding rules, and how to add input steps.

Skill: PythonPart Script

How the framework loads your script

Important: The framework never runs your script top-to-bottom. It loads it as a Python module and calls specific functions or methods from it. Do not put executable logic at module level — only imports, function definitions, and class definitions.

The framework is the caller. Your job is to implement the functions/methods/classes it expects.

Script Object contract

The Script Object is the default contract. It requires:

What to implement	Type	Required
check_allplan_version	module-level function	yes
create_script_object	module-level function	yes
A class inheriting BaseScriptObject	class	yes

Minimal templates

See templates/EntryPointFunctions.py for a ready-to-copy file containing only the functions that the framework calls, and templates/MyScriptObject.py for a ready-to-copy script object class template. In a simple case, both can be implemented in the same file.

Coding rules

• check_allplan_version and create_script_object are module-level functions, not methods.
• The script object class must inherit from BaseScriptObject.BaseScriptObject.
• execute() is the only mandatory method to override. It must return CreateElementResult.CreateElementResult.
• Access parameter values via self.build_ele.<ParameterName>.value. The name must match the <Name> tag in the PYP file.
• AllplanGeometry and AllplanBasisElements in the template are just examples. Remove them if not needed or add others as required — see etc\PythonPartsFramework\InterfaceStubs for all available API modules.
• Never instantiate DocumentAdapter and CoordinateInput directly — use the ones provided by the framework via self.document and self.coord_input.

Adding input steps

The Script Object contract allows adding interaction steps (point pick, element selection, etc.) between the palette and element creation. Override start_input() to launch the first step and start_next_input() for any subsequent ones.

Point pick

from ScriptObjectInteractors.PointInteractor import PointInteractor, PointInteractorResult

class MyPythonPart(BaseScriptObject):

    def start_input(self):
        self.point_result = PointInteractorResult()
        self.script_object_interactor = PointInteractor(self.point_result,
                                                        prompt_msg="Pick insertion point")

    def start_next_input(self):
        self.script_object_interactor = None   # no more steps after this

    def execute(self) -> CreateElementResult:
        insertion_point = self.point_result.point
        elements = ModelEleList()
        # ... use insertion_point ...
        return CreateElementResult(elements)

Single element selection

from ScriptObjectInteractors.SingleElementSelectInteractor import (
    SingleElementSelectInteractor, SingleElementSelectInteractorResult)

class MyPythonPart(BaseScriptObject):

    def start_input(self):
        self.sel_result = SingleElementSelectInteractorResult()
        self.script_object_interactor = SingleElementSelectInteractor(
            self.sel_result, prompt_msg="Select element")

    def start_next_input(self):
        self.script_object_interactor = None

    def execute(self) -> CreateElementResult:
        selected = self.sel_result.sel_element
        elements = ModelEleList()
        # ... process selected element ...
        return CreateElementResult(elements)

Set self.script_object_interactor = None in start_next_input() once there are no more steps. The framework calls execute() only after all input steps are finished.

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Optional methods on BaseScriptObject

Method	When called	Use it to
modify_element_property(page, name, value)	user changes a palette value	react to palette changes, update other params
on_control_event(build_ele, event_id)	user presses a palette button	handle button actions
on_cancel_function()	user presses Escape	clean up, cancel the input
start_input()	after palette closes, before execute()	launch first interaction step
start_next_input()	after each interaction step completes	launch next step or set interactor to None

Checklist before handing off

• Every parameter used like build_ele.Width exists in the PYP file as <Parameter> with <Name>Width</Name>
• execute() returns CreateElementResult
• No logic runs at module level (imports and function/class definitions only)
• check_allplan_version and create_script_object are present as module-level functions of the module referenced in <Script>/<Name> in the PYP file
• The class, whose instance is returned by create_script_object(), inherits from BaseScriptObject.BaseScriptObject

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Related guides

• Property Palette (UI Design) — defining parameters in the PYP file that the script reads via build_ele
• ALLPLAN Elements — how to create geometry and wrap it in AllplanElement objects for CreateElementResult.CreateElementResult
• Create a New PythonPart — end-to-end workflow