Open xml relationship target is NULL when inserting chart into a mapped rich text content control in Word 2013

Question

Hi,
I have a word document with a rich text content control that is mapped to a CustomXml. You can download an example here
http://1drv.ms/1raxoUr
I have looked into the specification ISO/IEC 29500-1:2012 and i understand that the attribute Target for the element Relationship can be set to NULL at times(Empty header and footer in the specification).
Now, i have stumbled on Target being NULL also when inserting a diagram into a word document. For example:
<Relationship Id="rId3" Type="http://schemas.openxmlformats.org/officeDocument/2006/relationships/oleObject"
Target="NULL" TargetMode="External" xmlns="http://schemas.openxmlformats.org/package/2006/relationships" />
Why is Target="NULL" and how should i interpret that Target is null?
Br,
/Peter
Peter

Answer 1

Hello Peter,
The relationship in question is associated with the externalData element (ISO/IEC 29500-1:2012 §21.2.2.63). For the other two charts in this document, the corresponding relationships are of the other allowable form:
  <Relationship Id="rId3" Type="http://schemas.openxmlformats.org/officeDocument/2006/relationships/package" Target="../embeddings/Microsoft_Excel_Worksheet1.xlsx"/>  <Relationship Id="rId3" Type="http://schemas.openxmlformats.org/officeDocument/2006/relationships/package" Target="../embeddings/Microsoft_Excel_Worksheet2.xlsx"/>
For charts 1 and 3 in your document, the data can be edited via the Chart Tools ribbon control. The option to edit data is not available for chart 2. The data used to create chart 2 is the same default spreadsheet data used for chart 1, and in fact the spreadsheet
references are still present in the file format, despite there being no apparent link to a spreadsheet for chart 2.
Thus, it appears that Target="NULL" in this context means that the chart is not associated with an external data source. The specification doesn't have much to say about the semantics of the Target attribute (ISO/IEC 29500-2:2012 §9.3.2.2) beyond
the fact that it be a valid xsd:anyURI, which the string "NULL" is.
It looks like there is some unexpected interaction between the chart and the content control. I don't think the file format is the issue. You will probably need to pursue that behavior from the product perspective via a support incident, if that behavior
is unexpected. If you still have questions about what is seen in the file format, please let me know.
Best regards,
Matt Weber | Microsoft Open Specifications Team