feature set: SmartArt support

[pipern]

I had a look into what it might take to be able to use placeholders that are within SmartArt elements (as a workaround which may be easier than full support for inserting new SmartArt), but it seems like some extra plumbing is needed - the placeholders are in related parts, and have a different representation (<dgm:prSet phldrT="[Text]" phldr="1"/> vs. the normal p:nvPr/p:ph)

The general approach seems to be a graphicFrame which contains a graphicData:

        <a:graphic>
          <a:graphicData uri="http://schemas.openxmlformats.org/drawingml/2006/diagram">
            <dgm:relIds xmlns:dgm="http://schemas.openxmlformats.org/drawingml/2006/diagram" xmlns:r="http://schemas.openxmlformats.org/officeDocument/2006/relationships" r:dm="rId2" r:lo="rId3" r:qs="rId4" r:cs="rId5"/>
          </a:graphicData>
        </a:graphic>

The relationships provide the layout of the shape, and the actual content:

  <Relationship Id="rId3" Type="http://schemas.openxmlformats.org/officeDocument/2006/relationships/diagramLayout" Target="../diagrams/layout1.xml"/>
  <Relationship Id="rId2" Type="http://schemas.openxmlformats.org/officeDocument/2006/relationships/diagramData" Target="../diagrams/data1.xml"/>
  <Relationship Id="rId5" Type="http://schemas.openxmlformats.org/officeDocument/2006/relationships/diagramColors" Target="../diagrams/colors1.xml"/>
  <Relationship Id="rId4" Type="http://schemas.openxmlformats.org/officeDocument/2006/relationships/diagramQuickStyle" Target="../diagrams/quickStyle1.xml"/>

The placeholders then look like this (from data1.xml):

<?xml version='1.0' encoding='UTF-8' standalone='yes'?>
<dgm:dataModel xmlns:dgm="http://schemas.openxmlformats.org/drawingml/2006/diagram" xmlns:a="http://schemas.openxmlformats.org/drawingml/2006/main">
  <dgm:ptLst>
    <dgm:pt modelId="{201DA834-84A2-4476-AFF7-041FCF65859D}" type="doc">
      <dgm:prSet loTypeId="urn:microsoft.com/office/officeart/2011/layout/CircleProcess" loCatId="process" qsTypeId="urn:microsoft.com/office/officeart/2005/8/quickstyle/simple1" qsCatId="simple" csTypeId="urn:microsoft.com/office/officeart/2005/8/colors/accent1_2" csCatId="accent1" phldr="0"/>
      <dgm:spPr/>
      <dgm:t>
        <a:bodyPr/>
        <a:lstStyle/>
        <a:p>
          <a:endParaRPr lang="en-GB"/>
        </a:p>
      </dgm:t>
    </dgm:pt>
    <dgm:pt modelId="{16AB87A3-ECFD-4530-9FA8-036018B97AE3}">
      <dgm:prSet phldrT="[Text]" phldr="1"/>
      <dgm:spPr/>
      <dgm:t>
        <a:bodyPr/>
        <a:lstStyle/>
        <a:p>
          <a:endParaRPr lang="en-GB"/>
        </a:p>
      </dgm:t>
    </dgm:pt>
...

I saw that I can find the related part's XML with shape.part.related_parts['rId2']. Possibly I can manipulate that directly.

This is the output of print prs.slides[0].shapes[0].part.blob:

<p:sld xmlns:a="http://schemas.openxmlformats.org/drawingml/2006/main" xmlns:r="http://schemas.openxmlformats.org/officeDocument/2006/relationships" xmlns:p="http://schemas.openxmlformats.org/presentationml/2006/main"><p:cSld><p:spTree><p:nvGrpSpPr><p:cNvPr id="1" name=""/><p:cNvGrpSpPr/><p:nvPr/></p:nvGrpSpPr><p:grpSpPr><a:xfrm><a:off x="0" y="0"/><a:ext cx="0" cy="0"/><a:chOff x="0" y="0"/><a:chExt cx="0" cy="0"/></a:xfrm></p:grpSpPr><p:graphicFrame><p:nvGraphicFramePr><p:cNvPr id="4" name="Diagram 3"/><p:cNvGraphicFramePr/><p:nvPr><p:extLst><p:ext uri="{D42A27DB-BD31-4B8C-83A1-F6EECF244321}"><p14:modId xmlns:p14="http://schemas.microsoft.com/office/powerpoint/2010/main" val="533975228"/></p:ext></p:extLst></p:nvPr></p:nvGraphicFramePr><p:xfrm><a:off x="1524000" y="1397000"/><a:ext cx="6096000" cy="4064000"/></p:xfrm><a:graphic><a:graphicData uri="http://schemas.openxmlformats.org/drawingml/2006/diagram"><dgm:relIds xmlns:dgm="http://schemas.openxmlformats.org/drawingml/2006/diagram" xmlns:r="http://schemas.openxmlformats.org/officeDocument/2006/relationships" r:dm="rId2" r:lo="rId3" r:qs="rId4" r:cs="rId5"/></a:graphicData></a:graphic></p:graphicFrame></p:spTree><p:extLst><p:ext uri="{BB962C8B-B14F-4D97-AF65-F5344CB8AC3E}"><p14:creationId xmlns:p14="http://schemas.microsoft.com/office/powerpoint/2010/main" val="646705655"/></p:ext></p:extLst></p:cSld><p:clrMapOvr><a:masterClrMapping/></p:clrMapOvr></p:sld>

To have something which can generate SmartArt, I thought of putting the SmartArt items I'd like to use into the slide layouts - and then populating the placeholders. This would be a temporary measure until an add_smartart() is created.

Unfortunately for now, it looks like this will take longer than I have to implement, but I wanted to at least create an issue to track and say what I know so far.