# Select
## Introduction
**`Select`** widget in Supervisely is a graphical user interface element that allows users to choose an option from a predefined list. It presents the options as a dropdown menu that can be expanded and collapsed by clicking. **`Select`** widget has event handler that is triggered when the user selects an option from the dropdown menu. This can be useful for applications that require users to take an action based on the selected option, such as filtering content or displaying specific information.
## Function signature
```python
Select(
items=None, groups=None,
filterable=False,
placeholder="select",
size=None,
multiple=False,
widget_id=None
)
```
## Parameters
| Parameters | Type | Description |
| :-----------: | :---------------------------------------: | :----------------------------------: |
| `items` | `List[Select.Item]` | List of `Select.Item` widgets |
| `groups` | `List[Select.Group]` | List of `Select.Group` widgets |
| `filterable` | `bool` | Whether `Select` is filterable |
| `placeholder` | `str` | Placeholder |
| `size` | `Literal["large", "small", "mini", None]` | Size of input |
| `multiple` | `bool` | Whether multiple-select is activated |
| `widget_id` | `str` | ID of the widget |
### items
Determine list of `Select.Item` widgets.
**type:** `List[Select.Item]`
**default value:** `None`
Prepare select items:
```python
animals_domestic = [
Select.Item(value="cat", label="cat"),
Select.Item(value="dog", label="dog"),
]
animals_wild = [
Select.Item(value="squirrel", label="squirrel"),
]
```
Initialize widget with given items:
```python
select_items = Select(
items=animals_domestic + animals_wild,
filterable=True,
)
```
### groups
Determine list of `Select.Group` widgets.
**type:** `List[Select.Group]`
**default value:** `None`
Prepare select items and groups:
```python
animals_domestic = [
Select.Item(value="cat", label="cat"),
Select.Item(value="dog", label="dog"),
]
animals_wild = [
Select.Item(value="squirrel", label="squirrel"),
]
groups = [
Select.Group(label="domestic", items=animals_domestic),
Select.Group(label="wild", items=animals_wild),
]
```
Initialize widget with given groups of items:
```python
select_groups = Select(groups=groups)
```
### filterable
Whether `Select` is filterable.
**type:** `bool`
**default value:** `false`
```python
select_items = Select(
items=animals_domestic + animals_wild,
filterable=True,
)
```
### placeholder
Placeholder. It needs to set `multiple=True` parameter.
**type:** `str`
**default value:** `select`
```python
select_items = Select(
items=animals_domestic + animals_wild,
multiple=True,
placeholder="Select animals",
)
```
### size
Size of input.
**type:** `Literal["large", "small", "mini", None]`
**default value:** `None`
```python
select = Select(items=animals_domestic)
select_mini = Select(items=animals_domestic, size="mini")
select_small = Select(items=animals_domestic, size="small")
select_large = Select(items=animals_domestic, size="large")
card = Card(content=Container(widgets=[select, select_mini, select_small, select_large]))
```
### multiple
Whether multiple-select is activated.
**type:** `bool`
**default value:** `false`
```python
select_items = Select(
items=animals_domestic + animals_wild,
multiple=True,
)
```
### widget\_id
ID of the widget.
**type:** `str`
**default value:** `None`
### Methods and attributes
| Attributes and Methods | Description |
| :-----------------------------------------------------------------------: | ----------------------------------------------------------- |
| `get_value()` | Return selected item value. |
| `get_items()` | Return list of items from widget. |
| `get_label()` | Return selected item label. |
| `get_labels()` | Return list of labels for all items |
| `set(items: List[Select.Item] = None, groups: List[Select.Group] = None)` | Set `Select` input items or group of items. |
| `set_value(value: str)` | Set `Select` input value. |
| `disable_item(item_index: int, group_index: int = None)` | Disable item by index. |
| `enable_item(item_index: int, group_index: int = None)` | Enable item by index. |
| `disable_group(group_index: int)` | Disable group by index. |
| `enable_group(group_index: int` | Enable group by index. |
| `@value_changed` | Decorator functions is handled when input value is changed. |
## Mini App Example
You can find this example in our Github repository:
[ui-widgets-demos/selection/001\_select/src/main.py](https://github.com/supervisely-ecosystem/ui-widgets-demos/blob/master/selection/001_select/src/main.py)
#### Import libraries
```python
import os
import supervisely as sly
from dotenv import load_dotenv
from supervisely.app.widgets import Card, Container, Select
```
### Init API client
First, we load environment variables with credentials and init API for communicating with Supervisely Instance:
```python
load_dotenv("local.env")
load_dotenv(os.path.expanduser("~/supervisely.env"))
api = sly.Api()
```
### Prepare items and groups of items for `Select` widget using `Select.Item` and `Select.Group`
```python
animals_domestic = [
Select.Item(value="cat", label="cat"),
Select.Item(value="dog", label="dog"),
Select.Item(value="horse", label="horse"),
Select.Item(value="sheep", label="sheep"),
]
animals_wild = [
Select.Item(value="squirrel", label="squirrel"),
]
groups = [
Select.Group(label="domestic", items=animals_domestic),
Select.Group(label="wild", items=animals_wild),
]
```
### Initialize `Select` widget
```python
select_items = Select(
items=animals_domestic + animals_wild,
filterable=True,
)
select_groups = Select(groups=groups)
```
### Create app layout
Prepare a layout for app using `Card` widget with the `content` parameter and place widget that we've just created in the `Container` widget.
```python
card = Card(
title="Select",
content=Container(widgets=[select_items, select_groups]),
)
layout = Container(widgets=[card])
```
### Create app using layout
Create an app object with layout parameter.
```python
app = sly.Application(layout=layout)
```
