Nodes sometimes don't have the is_visible attribute

[bchardin]

Describe the bug

svg2tikz fails to generate a valid output when the is_visible attribute does not exist.

Setup:

• Mode: shell tool
• SVG2TikZ version: 1.2 cc6cc42
• OS version: Debian 11
• Inkscape version: 1.0.2
• inkex version: 1.3.0

To Reproduce

Input SVG (generated with Inkscape):

<?xml version="1.0" encoding="UTF-8" standalone="no"?>
<svg
   xmlns:dc="http://purl.org/dc/elements/1.1/"
   xmlns:cc="http://creativecommons.org/ns#"
   xmlns:rdf="http://www.w3.org/1999/02/22-rdf-syntax-ns#"
   xmlns:svg="http://www.w3.org/2000/svg"
   xmlns="http://www.w3.org/2000/svg"
   xmlns:sodipodi="http://sodipodi.sourceforge.net/DTD/sodipodi-0.dtd"
   xmlns:inkscape="http://www.inkscape.org/namespaces/inkscape"
   width="210mm"
   height="297mm"
   viewBox="0 0 210 297"
   version="1.1"
   id="svg8"
   inkscape:version="1.0.2 (e86c870879, 2021-01-15)"
   sodipodi:docname="sample.svg">
  <defs
     id="defs2" />
  <sodipodi:namedview
     id="base"
     pagecolor="#ffffff"
     bordercolor="#666666"
     borderopacity="1.0"
     inkscape:pageopacity="0.0"
     inkscape:pageshadow="2"
     inkscape:zoom="0.35"
     inkscape:cx="400"
     inkscape:cy="560"
     inkscape:document-units="mm"
     inkscape:current-layer="layer1"
     inkscape:document-rotation="0"
     showgrid="false"
     inkscape:window-width="1533"
     inkscape:window-height="974"
     inkscape:window-x="26"
     inkscape:window-y="23"
     inkscape:window-maximized="0" />
  <metadata
     id="metadata5">
    <rdf:RDF>
      <cc:Work
         rdf:about="">
        <dc:format>image/svg+xml</dc:format>
        <dc:type
           rdf:resource="http://purl.org/dc/dcmitype/StillImage" />
        <dc:title></dc:title>
      </cc:Work>
    </rdf:RDF>
  </metadata>
  <g
     inkscape:label="Layer 1"
     inkscape:groupmode="layer"
     id="layer1">
    <circle
       style="fill:#ff0000;fill-rule:evenodd;stroke-width:0.264583"
       id="path1917"
       cx="93.138641"
       cy="127.18604"
       r="37.044617" />
  </g>
</svg>

Command used:

svg2tikz sample.svg

Output result:

Traceback (most recent call last):
  File "/home/bch/.local/bin/svg2tikz", line 8, in <module>
    sys.exit(main_cmdline())
  File "/home/bch/svg2tikz/svg2tikz/tikz_export.py", line 1421, in main_cmdline
    effect.convert(**kwargs)
  File "/home/bch/svg2tikz/svg2tikz/tikz_export.py", line 1376, in convert
    self.run()
  File "/home/bch/svg2tikz/svg2tikz/tikz_export.py", line 1349, in run
    self.save_raw(self.effect())
  File "/home/bch/svg2tikz/svg2tikz/tikz_export.py", line 1267, in effect
    string = self._output_group(nodes)
  File "/home/bch/svg2tikz/svg2tikz/tikz_export.py", line 1186, in _output_group
    goptions = self.style_to_tz(node) + self.trans_to_tz(node)
  File "/home/bch/svg2tikz/svg2tikz/tikz_export.py", line 772, in style_to_tz
    if style.get("display") == "none" or not node.is_visible:
  File "/home/bch/.local/lib/python3.9/site-packages/inkex/elements/_base.py", line 147, in __getattr__
    raise AttributeError(f"Can't find attribute {self.typename}.{name}")
AttributeError: Can't find attribute Metadata.is_visible

Expected behavior

I believe entities without the is_visible attribute could be considered visible instead of raising an error.

[ldevillez]

Hello @bchardin,
Thanks for finding this bug :)