Inkscape - save Tiny SVG (for QtSVG compliance)

Question

I have some graphics done in my favourite Inkscape and I need it to be Tiny SVG compliant in order to be able to drive it later pragmatically by QtSVG.

Collecting tiny bits and pieces from many different sources, I came with a following procedure:

1. Save as..
2. Choosing "Optimized SVG"
3. In the optimization dialog I checked (translated to EN):
   • Options
     • [x] Shorten color values
     • [x] Convert CSS properties to XML
     • [x] Collapse groups
     • [x] Create groups for similar attributes
     • [ ] Keep editor data
     • [ ] Keep unreferenced definitions
     • [x] Work around renderer bugs
   • SVG output
     • [ ] Remove XML declaration
     • [x] Remove metadata <<< Note: Important <<<
     • [ ] Remove comments
     • [x] Embed raster images
     • [ ] Enable viewboxing
     • [x] Format output with line-breaks and indentation
     • [ ] Strip the "xml:space" attribute from the root SVG element
   • ID
     • [ ] Remove unused IDs
     • [ ] Shorten IDs
     • [x] Preserve manually created IDs not ending with digits

Now it works, if the graphics does not contain a text. However I need the graphics to contain text, basically AFAIK meaning it must contain <text> elements.

My Inkscape is 1.0.1 running on OpenSuSE Leap 15.3 Linux system with "Optimized SVG" extension for Scour of version 0.31+. System tells me I have python3-scour 0.37-1.45.

The default format of the output for a text field from Inkscape is:

<text id="T1m" transform="translate(-4.4781 -24.9064)"
 fill="#000000" font-family="sans-serif" font-size="10.5833px"
 letter-spacing="0px" word-spacing="0px">
   <tspan x="46.580078" y="138.18859">
      <tspan>T</tspan>
      <tspan baseline-shift="sub" font-size="65%">1m</tspan> 
      <tspan>=15°C</tspan>
   </tspan>
</text>

That gives me errors like:

qt.svg: <input>:207:212: Could not add child element to parent element because the types are incorrect.
qt.svg: <input>:207:273: Could not add child element to parent element because the types are incorrect.
qt.svg: <input>:207:298: Could not add child element to parent element because the types are incorrect. 

...and the program subsequently crashes.

If I manually edit it removing <tspan> elements:

  <text id="T1m" transform="translate(-4.4781 -24.9064)" fill="#000000" font-family="sans-serif" font-size="10.5833px" letter-spacing="0px" word-spacing="0px">T1m=15°C</text>

...then I get no errors, but also no text in the graphics.

Could anyone advise how to get a compliant Tiny SVG from Inkscape? I.e. a change to the output dialogue, a CLI conversion tool or even a text-editor changes that make the text elements to work...

Answer 1

Since there was no answer, the only way I could resolve it is to manually edit the SVG file using the Tiny SVG documentation.

So I turned the line with text property mentioned in the question into following one:

<text id="T1m" fill="#000000" font-family="sans-serif" font-size="10px" letter-spacing="0px" word-spacing="0px" x="50" y="150">T1m=15°C</text>

Particularly the subscript and some tspan nesting and/or attributes seem to create issues. I needed to recalculate position coordinates too.

I'll see if I improve and automate this in future. Will expand this answer in such case.