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How to access template initial_arguments from dash app?

See original GitHub issue

For example I have the template.html:

{% extends "dashboards/base_generic.html" %} {% block content %} {% load plotly_dash %} {% plotly_app name="descriptive" ratio=0.75 initial_arguments='{"vehicle_data":{"make":"{{Make}}","model":"{{Model}}","year":"{{Year}}"}}' %} {% endblock %}

And in dash_app.py I have: app = DjangoDash(name='descriptive', id='vehicle_data')

Kind of confused what method I would use to access ‘vehicle_data’? Hopefully this is the right usage, new to Django and Dash.

Issue Analytics

State:
Created 4 years ago
Comments:7 (1 by maintainers)

Top GitHub Comments

2reactions

jfrostburkecommented, Dec 7, 2019

Result from me random-walking to the solution. For context, I was trying to access the id of a target in my database in an app that plots astronomical spectra.

Views.py

My views.py was already returning a context about, so I just added to it. This set the layers to unpack (dash_context, target_id, value):

context['dash_context'] = {'target_id': {'value': self.get_object().id}}

template.html

In my template I had to pass that new context to the app:

{% plotly_app name="Spectra" ratio=1.0 initial_arguments=dash_context %}

dash_app.py

I did this when I defined the app:

app = DjangoDash(name='Spectra', id='target_id')

When I defined the layout of the app I passed the target id in as a hidden input. The filler text got immediately overwritten so it’s not the most elegant:

app.layout = html.Div([
    . . .
    dcc.Input(id='target_id', type='hidden', value='filler text'),
    . . .

Then I had to pass in the value (the end goal that I wanted to access) in the callback:

 @app.expanded_callback(
    . . .
    Input('target_id', 'value')])
def display_output(. . . value):
    print(value)

Hopefully this is helpful to anyone trying to solve this in the future.

0reactions

pperum002ccommented, Jul 28, 2021

@nikhilnaregal - I also have similar requirement and I wasn’t able to find any solution for passing input from Django to Dash. However I found a workaround - that suits my requirement. Please check if its useful in your case.

views.py

from django.shortcuts import render

# Create your views here.

def home(request):
    return render(request, 'entry_ui_portion/home.html')

home.html

{%load plotly_dash%}
<!DOCTYPE html>
<html lang="en">

<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Release Plan</title>
</head>

<body>
    {%plotly_app name="ReleasePlanning" ratio=0.75%}
</body>

</html>

Now In the actual dash layout file - call django model and iterate thru the query - DOING JUST THIS WILL NOT FIX THE ISSUE (Instead - In the dash layout file use live updates with this method: https://dash.plotly.com/live-updates

example_dash_file.py

from <app_name>.models import <modelname>
other imports....
...

app = DjangoDash(name='ReleasePlanning', suppress_callback_exceptions=True)

def getContent():
    datadf = []
    for rows in <modelname>.objects.all():
        da = {}
        da['fname'] = rows.fname
        da['lname'] = rows.lname
        da['experience'] = float(rows.experience)
        da['domain'] = rows.domain

        datadf.append(da)
    return datadf

def serve_layout():

    resultdf = getContent()

    return html.Div(children=[
        html.Div(children=[
            html.H1('Heading')
        ], style={'font-family': 'Verdana', 'text-align': 'center', 'padding-down': '20px'}),

app.layout = serve_layout

#callbacks below if any - if datadf used in any callback - call getContent again

This may not be an effective solution, but it served the purpose of what a data feed from django to dash does is cleared in this method.