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Backend error 500 for SimpleExample demo app

See original GitHub issue

I think I followed the dev installation instructions:

# Using miniconda instead of virtualenv, but I doubt this is an issue
conda create -n dpd_dev python=3.6
conda activate dpd_dev

# following relevant ./make_env lines
pip install -r requirements.txt
pip install -r dev_requirements.txt
python setup.py develop

# prepare redis
docker pull redis:4
docker run -p 6379:6379 -d redis

# prepare demo
cd demo
./manage.py migrate
./manage.py shell < configdb.py
./manage.py collectstatic -i "*.py" -i "*.pyc" --noinput --link
./manage.py runserver --nostatic

# I later exited `runserver` to freeze packages those tested
pip install -r frozen_dev.txt
./manage.py runserver --nostatic

When I go to http://localhost:8000/demo-one I see the following:

and in the console I see

Internal Server Error: /django_plotly_dash/app/SimpleExample/_dash-update-component
Traceback (most recent call last):
  File "/Users/dwinston/miniconda3/envs/djd_dev/lib/python3.6/site-packages/django/core/handlers/exception.py", line 34, in inner
    response = get_response(request)
  File "/Users/dwinston/miniconda3/envs/djd_dev/lib/python3.6/site-packages/django/core/handlers/base.py", line 126, in _get_response
    response = self.process_exception_by_middleware(e, request)
  File "/Users/dwinston/miniconda3/envs/djd_dev/lib/python3.6/site-packages/django/core/handlers/base.py", line 124, in _get_response
    response = wrapped_callback(request, *callback_args, **callback_kwargs)
  File "/Users/dwinston/miniconda3/envs/djd_dev/lib/python3.6/site-packages/django/views/decorators/csrf.py", line 54, in wrapped_view
    return view_func(*args, **kwargs)
  File "/Users/dwinston/repos/django-plotly-dash/django_plotly_dash/views.py", line 77, in update
    resp = view_func()
  File "/Users/dwinston/repos/django-plotly-dash/django_plotly_dash/dash_wrapper.py", line 456, in dispatch
    return self. dispatch_with_args(body, argMap=dict())
  File "/Users/dwinston/repos/django-plotly-dash/django_plotly_dash/dash_wrapper.py", line 465, in dispatch_with_args
    target_id = '{}.{}'.format(output['id'], output['property'])
TypeError: string indices must be integers
Internal Server Error: /django_plotly_dash/app/SimpleExample/_dash-update-component
Traceback (most recent call last):
  File "/Users/dwinston/miniconda3/envs/djd_dev/lib/python3.6/site-packages/django/core/handlers/exception.py", line 34, in inner
    response = get_response(request)
  File "/Users/dwinston/miniconda3/envs/djd_dev/lib/python3.6/site-packages/django/core/handlers/base.py", line 126, in _get_response
    response = self.process_exception_by_middleware(e, request)
  File "/Users/dwinston/miniconda3/envs/djd_dev/lib/python3.6/site-packages/django/core/handlers/base.py", line 124, in _get_response
    response = wrapped_callback(request, *callback_args, **callback_kwargs)
  File "/Users/dwinston/miniconda3/envs/djd_dev/lib/python3.6/site-packages/django/views/decorators/csrf.py", line 54, in wrapped_view
    return view_func(*args, **kwargs)
  File "/Users/dwinston/repos/django-plotly-dash/django_plotly_dash/views.py", line 77, in update
    resp = view_func()
  File "/Users/dwinston/repos/django-plotly-dash/django_plotly_dash/dash_wrapper.py", line 456, in dispatch
    return self. dispatch_with_args(body, argMap=dict())
  File "/Users/dwinston/repos/django-plotly-dash/django_plotly_dash/dash_wrapper.py", line 465, in dispatch_with_args
    target_id = '{}.{}'.format(output['id'], output['property'])
TypeError: string indices must be integers
HTTP GET /django_plotly_dash/app/SimpleExample/_dash-component-suites/dash_core_components/dash_core_components.min.js.map 302 [0.03, 127.0.0.1:51759]
HTTP POST /django_plotly_dash/app/SimpleExample/_dash-update-component 500 [0.08, 127.0.0.1:51757]
HTTP POST /django_plotly_dash/app/SimpleExample/_dash-update-component 500 [0.08, 127.0.0.1:51755]
HTTP GET /static/dash/component/dash_core_components/dash_core_components.min.js.map 304 [0.00, 127.0.0.1:51759]

Any advice? It seems that the value of the ‘output’ key in the body argument passed to django_plotly_dash.dash_wrapper.dispatch_with_args is a string rather than dict-like. This is the basic first “hello world” demo, so I’m wondering if I’m installing everything properly.