# Choice

> A message with your own buttons. A native Pyzed component for Python desktop GUIs, with a live preview, code examples and its API.

Source: https://albakore.github.io/pyzed/library/choice/

:::tip[In plain words]
A question with several possible answers, each one a button.
:::

A message with your own buttons: `options` are `(label, on_press)` pairs and the last one is the main one.

`ui.choice` · Category: [Dialogs](https://albakore.github.io/pyzed/library/#dialogs) · [Full reference →](https://albakore.github.io/pyzed/reference/ui/#choice)

**Code:**

```python
ui.dialog_layer(main_view(), ui.choice(
    "notes.py already exists in this folder.",
    [("Keep both", on_keep), ("Skip", on_skip), ("Replace", on_replace)],
    on_cancel, title="File exists", width=420,
))
```

:::note[New]
This component was added recently. Tell us how it works for you in the [issue tracker](https://github.com/albakore/pyzed/issues).
:::

## When to use

- When a question has more than two answers (Keep both / Replace / Skip).

## Usage

```python
from pyzed import ui

ui.dialog_layer(main_view(), ui.choice(
    "notes.py already exists in this folder.",
    [("Keep both", on_keep), ("Skip", on_skip), ("Replace", on_replace)],
    on_cancel, title="File exists", width=420,
))
```

## Variants

:::note[About these captures]
Each capture is recorded by pyzed itself, off-screen at 2x, in One Dark or One Light to match this site's theme, and cropped to the component so it shows at its real size. The pointer hovers, presses or types into it; a component that does not react to the pointer cycles through a few themes. With reduced motion you see the first frame. Open **Code** under a capture to see the snippet that draws it; free names such as `on_save` stand for your own callbacks.
:::

### Options

```python
ui.choice("Open the project in…", [("This window", on_here), ("New window", on_new)],
          on_cancel, width=360)
```

```python
ui.choice("notes.py already exists.", [("Keep both", on_keep), ("Skip", on_skip),
          ("Replace", on_replace)], on_cancel, title="File exists", width=400)
```

## Events

Choice has **1 event of its own**, listed below. Like every widget it also has the **18 common events** (`click`, `double_click`, `right_click`, `mouse_enter`, `drag`, `key_down`, `resize`…), attached with `.on(...)`: see [Events](https://albakore.github.io/pyzed/guides/events/) and [Events of every component](https://albakore.github.io/pyzed/library/events/).

| Event | Handler gets | When |
| --- | --- | --- |
| `on_cancel` | `()` | The close icon. |

**Handler gets** is what Pyzed passes to your callable: `()` means nothing. Any handler can also be a message (a value that is not callable), which goes to `update()`.

### Handling the events

The same events written three ways. **Imperative**: methods of the app change `self`. **Declarative**: the handlers produce messages and one `update()` decides. **Functional**: a pure function draws an immutable state and asks for changes with `set_state(...)`. See [Imperative, declarative and functional](https://albakore.github.io/pyzed/guides/code-styles/).

**Imperative:**

```python
class Copy(pz.App):
    def __init__(self):
        self.asking, self.answer = True, None

    def answer_with(self, what):
        self.asking, self.answer = False, what

    def view(self):
        dialog = ui.choice("notes.py already exists in this folder.",
                           [("Keep both", lambda: self.answer_with("both")),   # one handler per option
                            ("Replace", lambda: self.answer_with("replace"))],
                           lambda: setattr(self, "asking", False),             # on_cancel: the ✕
                           title="File exists")
        return ui.dialog_layer(main_view(), dialog if self.asking else None)
```

**Declarative:**

```python
from dataclasses import dataclass

@dataclass
class Answer:
    what: str

class Copy(pz.App):
    asking = True

    def update(self, message):
        match message:
            case Answer(what):
                self.asking = False
                print("chose", what)
            case "cancel":
                self.asking = False

    def view(self):
        dialog = ui.choice("notes.py already exists.", [("Keep both", Answer("both")),
                                                        ("Replace", Answer("replace"))], "cancel")
        return ui.dialog_layer(main_view(), dialog if self.asking else None)
```

**Functional:**

```python
from dataclasses import dataclass

@dataclass(frozen=True)
class State:
    answer: str = ""

def view(state, set_state):
    if state.answer:
        return ui.label(f"You chose: {state.answer}")
    return ui.dialog_layer(main_view(), ui.choice(
        "notes.py already exists.",
        [(label, lambda a=answer: set_state(answer=a)) for label, answer in (("Keep both", "both"),
                                                                            ("Replace", "replace"))],
        lambda: set_state(answer="cancel")))
```

## Properties and API

### `ui.choice`

```python
choice(message, options, on_cancel, *, title=None, width=440, theme=None)
```

A message with your own buttons.

| Property | Default | Description |
| --- | --- | --- |
| `message` | *required* | Any Python value, or a callable. |
| `options` | *required* | `(label, on_press)` pairs; the last one is the main button. |
| `title` | `None` | Title. |
| `width` | `440` | Width: pixels, `"fill"`, `"shrink"` or `"fill:N"` (proportion). |
| `theme` | `None` | Theme to use instead of the current one (`pyzed.theme.current()`). |

Events: `on_cancel` ([events](#events)).

[Full reference →](https://albakore.github.io/pyzed/reference/ui/#choice)

## Related

- [Confirm](https://albakore.github.io/pyzed/library/confirm/): A yes/no question, red for destructive actions.
- [Unsaved changes](https://albakore.github.io/pyzed/library/unsaved-changes/): “Save your changes before closing?”