> For the complete documentation index, see [llms.txt](https://developer.supervisely.com/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://developer.supervisely.com/app-development/widgets/selection/tagslistselector.md).
# TagsListSelector
## Introduction
**`Tags List Selector`** widget allows users to view a list of tag metas and change it dynamically using widget methods. This widget can be used for visualizing and selecting tags in Supervisely.
## Function signature
```python
tags_list_selector = TagsListSelector(
tag_metas=tag_metas,
multiple=False,
empty_notification=None,
widget_id=None
)
```
{% tabs %}
{% tab title="Default with tags" %}
Default with tags
{% endtab %}
{% tab title="Default without tags" %}
Default without tags
{% endtab %}
{% endtabs %}
## Parameters
| Parameters | Type | Description |
| :------------------: | :---------------------------------------: | :------------------------------------------------------------------: |
| `tag_metas` | `Union[List[TagMeta], TagMetaCollection]` | Supervisely tag metas collection or list of tag metas |
| `multiple` | `bool` | Enable multiple tags selection |
| `empty_notification` | `NotificationBox` | Notification that will be displayed when there are no tags in widget |
| `widget_id` | `str` | ID of the widget |
### tag\_metas
List of `TagMeta` objects or Supervisely object class collection (`TagMetaCollection`).
**type:** `Union[List[TagMeta], TagMetaCollection]`
```python
tags_list_selector = TagsListSelector(
tag_metas=tag_metas
)
```
### multiple
If `True` then multiple tags can be selected. Otherwise, only one tag can be selected.
**type:** `bool`
**default** `False`
```python
tags_list_selector = TagsListSelector(
tag_metas=tag_metas,
multiple=True
)
```
{% tabs %}
{% tab title="Multiple Enabled" %}
Multiple Enabled
{% endtab %}
{% tab title="Multiple disabled" %}
Multiple disabled
{% endtab %}
{% endtabs %}
### empty\_notification
Notification that will be displayed when there are no tags in widget
**type:** `NotificationBox`
**default** `None`
```python
notification_box = NotificationBox(title="No tags", description="Provide tags to the widget.")
tags_list_selector = TagsListSelector(
tag_metas=tag_metas,
empty_notification=notification_box,
)
```
### widget\_id
ID of the widget.
**type:** `str`
**default value:** `None`
## Methods and attributes
| Attributes and Methods | Description |
| :--------------------: | -------------------------------------------- |
| `set()` | Set tags to widget. |
| `get_selected_tags()` | Return list of selected tags. |
| `select_all()` | Select all tags. |
| `deselect_all()` | Deselect all tags. |
| `select()` | Select tags by names. |
| `deselect()` | Deselect tags by names. |
| `set_multiple()` | Set multiple flag. |
| `get_all_tags()` | Return list of all tags. |
| `@selection_changed` | Callback triggers when selection is changed. |
## Mini App Example
You can find this example in our Github repository:
[supervisely-ecosystem/ui-widgets-demos/selection/017\_tags\_list\_selector/src/main.py](https://github.com/supervisely-ecosystem/ui-widgets-demos/blob/master/selection/017_tags_list_selector/src/main.py)
### Import libraries
```python
import os
import supervisely as sly
from supervisely.app.widgets import Card, Container, TagsListSelector, Text, NotificationBox
from dotenv import load_dotenv
```
### 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()
```
### Create list of tag metas
```python
cat_tag_meta = sly.TagMeta("cat", sly.TagValueType.NONE)
dog_tag_meta = sly.TagMeta("dog", sly.TagValueType.ANY_NUMBER)
horse_tag_meta = sly.TagMeta("horse", sly.TagValueType.ANY_STRING)
cow_tag_meta = sly.TagMeta("cow", sly.TagValueType.ONEOF_STRING, possible_values=["moo", "mooo"])
zebra_tag_meta = sly.TagMeta("zebra", sly.TagValueType.NONE)
tag_metas = [
cat_tag_meta,
dog_tag_meta,
horse_tag_meta,
cow_tag_meta,
zebra_tag_meta,
]
```
### Initialize `TagsListSelector` widget, `NotificationBox` widget for custom notification and `Text` widget for displaying selected tags count
```python
notification_box = NotificationBox(title="No tags", description="Provide tags to the widget.")
tags_list_selector = TagsListSelector(tag_metas, multiple=True, empty_notification=notification_box)
selected_tags_cnt = Text(f"Selected Tags: 0 / {len(tag_metas)}")
```
### Create app layout
Prepare a layout for app using `Card` widget with the `content` parameter and place widget that we've just created into the `Container` widget.
```python
container = Container(widgets=[selected_tags_cnt, tags_list_selector])
card = Card(
title="Tags List Selector",
content=container,
)
layout = card
```
### Create app using layout
Create an app object with layout parameter.
```python
app = sly.Application(layout=layout)
```
### Add functions to control widgets from python code
```python
@tags_list_selector.selection_changed
def on_selection_changed(selected_tags):
selected_tags_cnt.set(f"Selected Tags: {len(selected_tags)} / {len(tag_metas)}", "text")
```
