Fun and funky loading spinners for your Dash apps
npm install dash_loading_spinners
!PyPI
!PyPI - License
!PyPI - Python Version
This library is designed for use with Plotly Dash. The components have all been
designed to provide functionality similar to Dash's core Loading component,
and will display a loading spinner whilst the underlying children are re-rendering.
The spinners in it have been adapted for use from a number of other existing
libraries:
- react-spinners
- react-loader-spinner
- react-css-spinners
The majority of spinner names have been retained from the originals, but some have
been amended where there were name clashes.
More details on the components and usage can be found in our documentation.
---
Dash Loading Spinners is available through
PyPI, and can be installed with pip:
``bash`
pip install dash-loading-spinners
---
Once installed, you can make use of the components (in their most basic sense) as follows:
`python
import dash
import dash_loading_spinners as dls
app = dash.Dash()
app.layout = dls.Hash()
if __name__ == "__main__":
app.run_server()
`
There are a number of attributes which are common across all spinners. These are:
- id (string; optional):
The ID of this component, used to identify dash components in
callbacks. The ID needs to be unique across all of the components
in an app.
- children (a list of or a singular dash component, string or number; optional):
The children of this component.
- show_initially (boolean; default True):debounce
Whether the Spinner should show on app start-up before the loading
state has been determined. Default True.
- (number; default 0):fullscreen
When using the spinner as a loading spinner, add a time delay (in
ms) to the spinner being removed to prevent flickering.
- (boolean; optional):fullscreenClassName
Boolean that determines if the loading spinner will be displayed
full-screen or not.
- (string; optional):fullscreen_style
CSS class names to apply to the container when in fullscreen.
- (dict; optional):
Defines CSS styles for the container when in fullscreen.
Many spinners additional have properties that can be customised, including colour and size. You
can find these on the individual component pages.
Realistically, as part of an application, you will be using them alongside other components and
callbacks. Here is an example of what this might look like:
_Note:
dash-bootstrap-components
isn't necessary for dash-loading-spinners to work, but has been included
to improve the layout._
`pythonapp.py
import dash
import dash_bootstrap_components as dbc
import dash_loading_spinners as dls
from dash import dcc, html, Input, Output
from helpers import get_new_graph
app = dash.Dash(external_stylesheets=[dbc.themes.UNITED])
app.layout = html.Div(
[
dbc.Row(
[
dbc.Col(
html.Div(
dbc.Button(
"Simulate slow loading component",
id="loading-button",
className="btn-success",
n_clicks=0,
)
),
md=3,
),
dbc.Col(
dls.Hash(
dcc.Graph(id="loading-output",),
color="#435278",
speed_multiplier=2,
size=100,
),
md=9,
),
],
),
]
)
@app.callback(
Output("loading-output", "figure"), [Input("loading-button", "n_clicks")],
)
def load_output(n):
# See note below
return get_new_graph(n)
if __name__ == "__main__":
app.run_server()
`
The function get_new_graph in this example is deliberately ambiguous, as it simply acts as a placeholder for any slow-loading component. For completeness, if you wish to use a similar example to the one shown above, you can use the following function:
`pythonhelpers.py
import numpy as np
import plotly.graph_objects as go
import time
def get_new_graph(n):
if n:
# Simulate slow-loading component
time.sleep(2)
# Generate a random scatter plot
n = (n + 1) * 10
return go.Figure(
data=go.Scatter(
y=np.random.randn(n) * 100,
mode="markers",
marker=dict(
size=16,
color=np.random.randn(n) * 100,
colorscale="blues",
showscale=True,
),
),
layout=go.Layout(title="This graph takes ages to re-load"),
)
``