Update OpenFOAM example to reuse Reader

[MatthewFlamm]

Overview

#2485 fixed OpenFOAMReader to be able to reuse the reader object for time steps. This PR updates the example to take advantage of this.

[codecov]

Codecov Report

Merging #2530 (1f3883b) into main (b6ab604) will decrease coverage by 0.00%.
The diff coverage is n/a.

@@            Coverage Diff             @@
##             main    #2530      +/-   ##
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- Coverage   93.72%   93.72%   -0.01%     
==========================================
  Files          75       75              
  Lines       16116    16120       +4     
==========================================
+ Hits        15105    15108       +3     
- Misses       1011     1012       +1     

[adeak]

LGTM, thanks.

One barely related thing I noticed: in the built example some names get intersphinx links:

filename links to stdlib str which is fair enough. But pyvista.OpenFOAMReader links to abc.ABC which is not very helpful. Do you think we should try to investigate this?

[MatthewFlamm]

filename links to stdlib str which is fair enough. But pyvista.OpenFOAMReader links to abc.ABC which is not very helpful. Do you think we should try to investigate this?

Other objects in the pyvista namespace are not linked in code blocks. This makes me suspect that the linking will look backwards into the inheritance until it finds a valid hit, in this case abc.ABC. object must not register in the same way?

[MatthewFlamm]

Is there a way to get the linking to work for PyVista classes?

[adeak]

I have no idea what component is doing this, then again I don't really know sphinx or numpydoc. I tried an extension in #1845 but that didn't really go anywhere.

[adeak]

I wonder what happens if we add pyvista to the intersphinx mapping dict... 😄

[MatthewFlamm]

🙃 . I can't find any of this linking in code blocks in the docstring examples. It seems to be contained in the examples section. I think that the examples are created before the package documentation, so this might be the root cause?

[adeak]

Good point, that might be it. Out of curiosity I'll see what happens if I try to add the intersphinx mapping from dev.pyvista.org. I expect our regular links to break (be redirected to dev.pyvista.org).

I think the feature we see is "global variable inspection" from sphinx-gallery. Haven't figured out what we can do about it (short of building the examples in a separate step if your hunch is correct).

[MatthewFlamm]

There is also this section, but it is not explicitly configured here. https://sphinx-gallery.github.io/stable/configuration.html#add-intersphinx-links-to-your-examples

[adeak]

I could only find this related issue/feature request, concerning interconnected libraries. One workaround mentions building HTML twice but that* doesn't seem to help for me. I don't know if something like sphinx-doc/sphinx#3426 (comment) could work.

*I should clarify that I literally just tried make html a second time. I assume sphinx figured that everything is up to date. I expect that deleting the built docs (but not the built doc/_build/html/objects.inv file) would work.

[tkoyama010]

Good catch. LGTM.

[adeak]

For the record I deleted all of doc/_build/html, recreated doc/_build/html (just the directory) and put objects.inv from a full build back into it. Rerunning make html didn't fix the OpenFOAMReader intersphinx link I pointed out above.