Our current work project involves opening a Microsoft PowerPoint file (.pptx format), changing some text and chart values, and then presenting the edited version to the end user.
This works rather well so far, but I'm puzzled by what happens when I try to validate the document afterwards. Using the DocumentFormat.OpenXml.Validation.OpenXmlValidator class, I run the Validate function with the PresentationDocument passed in as the only parameter.
Dim document As PresentationDocument = PresentationDocument.Open(templateFilePath, True)
Dim validator As OpenXmlValidator = New OpenXmlValidator()
Dim errors = validator.Validate(document)
For Each errInfo As ValidationErrorInfo In errors
Debug.Print("Error: """ & errInfo .Description & """")
Debug.Print("XPath: " & errInfo .Path.XPath)
Next
Validate() returns an array filled with instances of ValidationErrorInfo. Just about all of these give the same error description when debugging:
The 'smtClean' attribute is not declared.
The XPath for each error looks like this (numbers vary; there appears to be one error per piece of text):
/p:sldLayout[1]/p:cSld[1]/p:spTree[1]/p:sp[4]/p:txBody[1]/a:p[1]/a:fld[1]/a:rPr[1]
Every TableCell has a Paragraph, with child element Run, and this Run has child elements RunProperties and Text. I modify the Text in my scripts, but I do not touch anything else.
Searching for 'smtClean' gave me an MSDN entry for RunProperties which shows 'smtClean' as one of the possible values to be set, but if I create a new instance of DocumentFormat.OpenXml.Presentation.Drawing.RunProperties the 'smtClean' attribute is not available.
Looking around, I found threads where people mentioned merged documents to be one possible cause, but these errors occur even in an unmodified presentation with only a single slide and table in it. Using the Open XML SDK 2.5 Productivity Tool to Validate the base document, I get the same result.
The errors also occur no matter which format I ask the Validator to test for - both the 2007, 2010 and 2013 version of the PowerPoint format return the same amount of errors.
Finally: The file itself works just fine in PowerPoint, even after being modified. I am curious about why the validator returns so many errors, however.
Thanks in advance for any help.
