composeui.core.model

The model: the app’s data beside its views, saved and opened with them in a study.

exception composeui.core.model.InvalidStateError

Bases: ValueError

A saved study that can’t be opened; the views and the model are left unchanged.

class composeui.core.model.Model

Bases: object

The app’s data beside its views, given to the callbacks asking for model.

A model with data of its own names its file in data_name. The study is then saved as an archive of the views’ state and that file (see composeui.core.study). New, Open and Save reach the model through the methods below. Without a data_name, Save and Open don’t call save_data and open_data, and the study stays the views’ JSON.

data_name: ClassVar[str | None] = None

the model’s file inside a saved study; None for a model with nothing to save

property signals: list[Signal[Unpack[tuple[Any, ...]]]]

Get the model’s signals: its attributes that are one, unless a subclass adds some.

The app gives them the main view and the model, as it does the views’ own signals. A callback that asks for main_view or model by name gets it.

new()

Start the data of a new study.

Return type:

None

save_data(path)

Write the data into the file path.

Parameters:

path (Path)

Return type:

None

open_data(path)

Replace the data with the file path’s.

Raises InvalidStateError, leaving the data unchanged, for a file that doesn’t fit.

Parameters:

path (Path)

Return type:

None

loaded()

React once New or Open has put both the views and the data in place.

MainView.loaded is emitted next, so the views’ callbacks read the data in place.

Return type:

None

close()

Release what the data holds (files, connections); the app is done with it.

Return type:

None

exception composeui.core.model.RefusedError

Bases: Exception

A change the model refused, changing nothing.

Its message tells the user why, as written in the code (View.refusing translates it), or translated already by a view’s tr.