Step Actions

Step actions live in portion/step_actions/. Each one maps to a type value in a portion's steps list and is responsible for executing one unit of work during a portion build run.

How They Work

All actions subclass ActionBase[TStep] and implement two methods:

class MyAction(ActionBase[MyStep]):
    def prepare(self) -> None:
        # Resolve variables, validate fields
        ...

    def apply(self) -> None:
        # Execute the change
        ...

Steps in a portion share a memory dict — a plain dict[str, str] that is passed through every action in the run. ask and set_var write to it; all other actions read from it through the Resolver.

The factory function create_action() in portion/step_actions/__init__.py maps a step type string to the correct action class.

Available Actions

Type	Class	What it does
`ask`	`AskAction`	Prompts the user and stores the answer in `memory`
`set_var`	`SetVarAction`	Derives a new variable from a fixed value or an existing one and stores it in `memory`
`copy`	`CopyAction`	Copies a file from `.portions/` into the project
`replace`	`ReplaceAction`	Replaces keyword placeholders in a file
`add_import`	`AddImportAction`	Appends an import statement to a Python file
`add_to_list`	`AddToListAction`	Appends a value to a Python list variable in a file

File Map

File	Class
`step_actions/ask.py`	`AskAction`
`step_actions/set_var.py`	`SetVarAction`
`step_actions/copy.py`	`CopyAction`
`step_actions/replace.py`	`ReplaceAction`
`step_actions/add_import.py`	`AddImportAction`
`step_actions/add_to_list.py`	`AddToListAction`
`step_actions/__init__.py`	`create_action()` factory