Custom schemes about map-machine

[enzet]

No problems at all, I should definitely add this option.

The scheme format however is still under development and not documented. If you want to create custom scheme, please feel free to ask questions.

[mfbehrens99]

Definitively, do not really understand it. Just tried an empty scheme and I failed. I only added the color definition from the default scheme in what made the program work. However, there are still a lot of objects on the map. Shouldn't an empty scheme result in an empty map?

[enzet]

I only added the color definition from the default scheme in what made the program work.

This is indeed a bug. Totally empty scheme file should work. I'll fix it.

Shouldn't an empty scheme result in an empty map?

Hmm... Looks like very legal assumption.

Honestly, I never thought about such a use case. Map Machine just tries to render everything no matter how and this behavior isn't manageable through scheme file.

[mfbehrens99]

Still throws an error message :(

(.env) C:\Users\mfbeh\Documents\Github\map-machine>map-machine render -b=8.4214801253,49.0197665932,8.4230425121,49.0205831971 -z=21 --scheme=map_machine/scheme/empty.yml
Traceback (most recent call last):
  File "C:\Users\mfbeh\Documents\Github\map-machine\.env\Scripts\map-machine-script.py", line 33, in <module>
    sys.exit(load_entry_point('map-machine', 'console_scripts', 'map-machine')())
  File "c:\users\mfbeh\documents\github\map-machine\map_machine\main.py", line 44, in main
    mapper.render_map(arguments)
  File "c:\users\mfbeh\documents\github\map-machine\map_machine\mapper.py", line 270, in render_map
    scheme: Scheme = Scheme.from_file(scheme_path)
  File "c:\users\mfbeh\documents\github\map-machine\map_machine\scheme.py", line 375, in from_file
    return cls(content)
  File "c:\users\mfbeh\documents\github\map-machine\map_machine\scheme.py", line 319, in __init__
    if "node_icons" in content:
TypeError: argument of type 'NoneType' is not iterable```

[enzet]

Hm, seems like YAML failed to load the file. Could you please dump the content of map_machine/scheme/empty.yml?

Update: oh, I see, it is just totally empty, which is presumably a valid YAML file. I'll check this.