Adding a webApp example using Dash

[rs-bh-n]

Added a Webapp example for Dash with PyMapdl : 1 file ,1 "assets" folder with four files and a README.txt

[codecov]

Codecov Report

Merging #1497 (f364b24) into main (70c6b3b) will decrease coverage by 4.00%.
The diff coverage is n/a.

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- Coverage   85.18%   81.17%   -4.01%     
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  Files          45       45              
  Lines        7511     7506       -5     
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- Hits         6398     6093     -305     
- Misses       1113     1413     +300     

[akaszynski]

@germa89, leaving this for you to review.

We can also consider a separate repo for this.

[germa89]

Hi @rs-bh-n

Thank you for this contribution.

I did have a look at the example.

And I couldn't make it work, terminal was complaining about:

[2022-09-21 16:35:14,305] ERROR in app: Exception on /_dash-update-component [POST]
Traceback (most recent call last):
  File "C:\ProgramData\Miniconda3\envs\pymapdl_0\lib\site-packages\flask\app.py", line 2525, in wsgi_app
    response = self.full_dispatch_request()
  File "C:\ProgramData\Miniconda3\envs\pymapdl_0\lib\site-packages\flask\app.py", line 1822, in full_dispatch_request
    rv = self.handle_user_exception(e)
  File "C:\ProgramData\Miniconda3\envs\pymapdl_0\lib\site-packages\flask\app.py", line 1820, in full_dispatch_request
    rv = self.dispatch_request()
  File "C:\ProgramData\Miniconda3\envs\pymapdl_0\lib\site-packages\flask\app.py", line 1796, in dispatch_request
    return self.ensure_sync(self.view_functions[rule.endpoint])(**view_args)
  File "C:\ProgramData\Miniconda3\envs\pymapdl_0\lib\site-packages\dash\dash.py", line 1259, in dispatch
    ctx.run(
  File "C:\ProgramData\Miniconda3\envs\pymapdl_0\lib\site-packages\dash\_callback.py", line 439, in add_context
    output_value = func(*func_args, **func_kwargs)  # %% callback invoked %%
  File "C:\Users\gayuso\Others_pymapdls\pymapdl_0\pymapdl\examples\07-webapps\dash-vm35\BimetallicStrip.py", line 571, in start_pymapdl
    p_run = pyMapdl_vm35(float(L), float(t), float(tr), float(ta), float(e1), float(e2), float(c1), float(c2))
  File "C:\Users\gayuso\Others_pymapdls\pymapdl_0\pymapdl\examples\07-webapps\dash-vm35\BimetallicStrip.py", line 77, in pyMapdl_vm35
    with open(data_file, 'a', newline='\n') as f:
FileNotFoundError: [Errno 2] No such file or directory: 'C:\\Users\\gayuso\\Others_pymapdls\\pymapdl_0\\pymapdl\\assets\\data.csv'
127.0.0.1 - - [21/Sep/2022 16:35:14] "POST /_dash-update-component HTTP/1.1" 500 -

I think you are not referencing correctly the location of data.csv:

FileNotFoundError: [Errno 2] No such file or directory: 'C:\\Users\\gayuso\\Others_pymapdls\\pymapdl_0\\pymapdl\\assets\\data.csv'

In the meantime, I'm thinking what to do with this example. Because it is mean to have a running MAPDL (docker image probably) on the background to perform the calculations.
I don't think we have that capability in the current documentation implementation, and that suppose a cost (keeping the MAPDL running) and a complication (because of the required infrastructure).

I'm a bit short of manpower at the moment, so I cannot spend as much time as I would like on this. So I would say to create its own repository, so we can make it installable, and someone can run it locally easily. We can upload images of the websites, even gifs, .... I will reference it in the PyMAPDL documentation website.

I think this is a good compromise between complexity and available time. What do you think @rs-bh-n ??

[rs-bh-n]

Hi @germa89 ,
Thanks for checking .

1. The py file expects the assets folder in the same directory (as the py file) .
   a) Can you check with the assets folder in place?
   b) Should the files (py_file and assets_folder) be zipped to avoid this confusion ?

2. I did not intend to run a webapp on our server that anybody can access anytime , I understand the complications .
   This example is just a simple demonstration of :
   - how pymapdl can be used as a backend (for a webapp created by user with dash as front end) and
   - how to launch the webapp and interact with backend server (this uses his/her local mapdl installation )

The users can later, with their IT team's help, probably explore webApp deployment(which is out of scope for us) for his/her team. What do you say , @germa89 ?

[germa89]

I'm moving this to the example repo: https://github.com/pyansys/pymapdl-examples

[germa89]

Actually no... in that repo there is no general examples. Keeping it here.

[germa89]

@rs-bh-n please have a look of the new proposal.

[germa89]

Merging. Comments or feedback will be added on a later PR.