g.gui.iclass: Add explanation of expected format for vector layers

[dhdeangelis]

g.gui.class allows for importing training areas from vector layers. However, it is not clear from the manual that some specific columns are desirable ('cat', 'class', 'color'). This PR addresses this issue by adding a clarification.

[echoix]

@neteler The contents are correct, but how do we handle the particularities of the g.html2man.py that can't handle line breaks in <dt>...</dt> and g.gui.iclass.html:165:0: Error (IndexError('pop from empty list')): </p> in the Travis Build?

https://app.travis-ci.com/github/OSGeo/grass/jobs/626613157#L13795

make[4]: '/home/travis/build/OSGeo/grass/dist.x86_64-pc-linux-gnu/docs/man/man1/g.gui.1' is up to date.
can't handle line breaks in <dt>...</dt>
VERSION_NUMBER=8.5.0dev /home/travis/build/OSGeo/grass/dist.x86_64-pc-linux-gnu/utils/g.html2man.py "/home/travis/build/OSGeo/grass/dist.x86_64-pc-linux-gnu/docs/html/g.gui.iclass.html" "/home/travis/build/OSGeo/grass/dist.x86_64-pc-linux-gnu/docs/man/man1/g.gui.iclass.1"
VERSION_NUMBER=8.5.0dev /home/travis/build/OSGeo/grass/dist.x86_64-pc-linux-gnu/utils/g.html2man.py "/home/travis/build/OSGeo/grass/dist.x86_64-pc-linux-gnu/docs/html/g.gui.image2target.html" "/home/travis/build/OSGeo/grass/dist.x86_64-pc-linux-gnu/docs/man/man1/g.gui.image2target.1"
/home/travis/build/OSGeo/grass/dist.x86_64-pc-linux-gnu/docs/html/g.gui.iclass.html:165:0: Error (IndexError('pop from empty list')): </p>
make[4]: *** [../include/Make/Html.make:11: /home/travis/build/OSGeo/grass/dist.x86_64-pc-linux-gnu/docs/man/man1/g.gui.iclass.1] Error 1
make[4]: *** Waiting for unfinished jobs....
can't handle line breaks in <dt>...</dt>
make[4]: Leaving directory '/home/travis/build/OSGeo/grass/man'
make[3]: *** [Makefile:57: manpages] Error 2

It's valid html right?

[dhdeangelis]

This is what I added:

<p><em>wxIClass</em> can also import training areas defined in a vector layer. In that case the program expects the vector layer to have the following columns defined:
<ul>
    <li>cat: category value</li>
    <li>class: a string with the class name</li>
    <li>color: a color defined using a with format "RRR:GGG:BBB"</li>
</ul>
</p>

The html is correct IMO. What is it exactly that cannot be handled? Is line 64 too long?

OTOH I see there is a typo in my change, line 68, it should read a color defined using format "RRR:GGG:BBB

[echoix]

I'm sure it's that our code doesn't like </p>, but it is unexpected to me.

[dhdeangelis]

How could I amend the PR to solve the typo I submitted in a 'gracious' git way?

[echoix]

Any way you'd like, we squash-merge and can edit the message before merging. Since there are no review comments yet, you can even force-push as much as you want without causing any problems.

[dhdeangelis]

OK. Let's see how it works. I did a "git amend" and a "git push -f". I corrected the typo and even deleted the potentially problematic </ ul > and < /p >

[echoix]

But we probably need the closing </ul> though

[dhdeangelis]

I see. I'll fix it now.

[echoix]

Thanks!

[neteler]

@neteler The contents are correct, but how do we handle the particularities of the g.html2man.py that can't handle line breaks in <dt>...</dt> and g.gui.iclass.html:165:0: Error (IndexError('pop from empty list')): </p> in the Travis Build?

https://app.travis-ci.com/github/OSGeo/grass/jobs/626613157#L13795

make[4]: '/home/travis/build/OSGeo/grass/dist.x86_64-pc-linux-gnu/docs/man/man1/g.gui.1' is up to date.
can't handle line breaks in <dt>...</dt>
VERSION_NUMBER=8.5.0dev /home/travis/build/OSGeo/grass/dist.x86_64-pc-linux-gnu/utils/g.html2man.py "/home/travis/build/OSGeo/grass/dist.x86_64-pc-linux-gnu/docs/html/g.gui.iclass.html" "/home/travis/build/OSGeo/grass/dist.x86_64-pc-linux-gnu/docs/man/man1/g.gui.iclass.1"
VERSION_NUMBER=8.5.0dev /home/travis/build/OSGeo/grass/dist.x86_64-pc-linux-gnu/utils/g.html2man.py "/home/travis/build/OSGeo/grass/dist.x86_64-pc-linux-gnu/docs/html/g.gui.image2target.html" "/home/travis/build/OSGeo/grass/dist.x86_64-pc-linux-gnu/docs/man/man1/g.gui.image2target.1"
/home/travis/build/OSGeo/grass/dist.x86_64-pc-linux-gnu/docs/html/g.gui.iclass.html:165:0: Error (IndexError('pop from empty list')): </p>
make[4]: *** [../include/Make/Html.make:11: /home/travis/build/OSGeo/grass/dist.x86_64-pc-linux-gnu/docs/man/man1/g.gui.iclass.1] Error 1
make[4]: *** Waiting for unfinished jobs....
can't handle line breaks in <dt>...</dt>
make[4]: Leaving directory '/home/travis/build/OSGeo/grass/man'
make[3]: *** [Makefile:57: manpages] Error 2

It's valid html right?

If it's valid (cannot check today) then we would need to update g.html2man.

[echoix]

Maybe related: #2668