Enclose spaces with tx tag so that they are restored as separate strings

[arisktfx]

Problem and/or solution

In pptx, when a paragraph contains one or more empty (only spaces) a:t tags, it prepents the spaces to the next text element, without creating a new openstring. This could not be handled correctly when compiling the file, which then generates a corrupted pptx file when opened with MS PowerPoint. Enclosing the empty a:t tags with a tx tag as we do with other string will retain the correct format of the document. Since this is a braking chacnge, the common parse_paragraph, compile_paragraph functions where moved to the PptxHandler class so that only the pptx file format is affected (not docx).

How to test

Parse a slide that contains the following paragraph

<a:p>
  <a:pPr algn="l" indent="0" lvl="0" marL="0" rtl="0"
  >
    <a:spcBef>
      <a:spcPts val="0" />
    </a:spcBef>
    <a:spcAft>
      <a:spcPts val="0" />
    </a:spcAft>
    <a:buNone />
  </a:pPr>
  <a:r>
    <a:rPr lang="en" sz="2400"
    >
      <a:solidFill>
        <a:srgbClr val="FFFFFF" />
      </a:solidFill>
      <a:latin typeface="Roboto Mono" />
      <a:ea typeface="Roboto Mono" />
      <a:cs
        typeface="Roboto Mono" />
      <a:sym typeface="Roboto Mono" />
    </a:rPr>
    <a:t>First string</a:t>
  </a:r>
  <a:r>
    <a:rPr lang="en" sz="4000"
    >
      <a:solidFill>
        <a:srgbClr val="FFFFFF" />
      </a:solidFill>
      <a:latin typeface="Roboto Mono" />
      <a:ea typeface="Roboto Mono" />
      <a:cs
        typeface="Roboto Mono" />
      <a:sym typeface="Roboto Mono" />
    </a:rPr>
    <a:t> </a:t>
  </a:r>
  <a:br>
    <a:rPr lang="en" sz="4000"
    >
      <a:solidFill>
        <a:srgbClr val="FFFFFF" />
      </a:solidFill>
      <a:latin typeface="Roboto Mono" />
      <a:ea typeface="Roboto Mono" />
      <a:cs
        typeface="Roboto Mono" />
      <a:sym typeface="Roboto Mono" />
    </a:rPr>
  </a:br>
  <a:r>
    <a:rPr b="1" lang="en" sz="4800"
    >
      <a:solidFill>
        <a:srgbClr val="00FFFF" />
      </a:solidFill>
      <a:latin typeface="Roboto" />
      <a:ea typeface="Roboto" />
      <a:cs
        typeface="Roboto" />
      <a:sym typeface="Roboto" />
    </a:rPr>
    <a:t>last string</a:t>
  </a:r>
  <a:endParaRPr b="1" sz="4800"
  >
    <a:solidFill>
      <a:srgbClr val="00FFFF" />
    </a:solidFill>
    <a:latin typeface="Roboto" />
    <a:ea typeface="Roboto" />
    <a:cs
      typeface="Roboto" />
    <a:sym typeface="Roboto" />
  </a:endParaRPr>
</a:p>

Reviewer checklist

Code:

• Change is covered by unit-tests
• Code is well documented, well styled and is following best practices
• Performance issues have been taken under consideration
• Errors and other edge-cases are handled properly

PR:

• Problem and/or solution are well-explained
• Commits have been squashed so that each one has a clear purpose
• Commits have a proper commit message according to TEM

[foteinigk]

Fix works great!! 🚀
let's decide only if we would need a new version parser for this fix

[deathbird]

Great fix @arisktfx 💪 !!