ChartExtension and ChartExtensionList are not implemented #1877
Description
Describe the bug
The feature extension and extension list ChartExtension and ChartExtensionList are not implemented.
Screenshots
If applicable, add screenshots to help explain your problem.
To Reproduce
Validate a file that has a valid c:ext and c:extList children of c:chart
Observed behavior
The elements are incorrectly flagged as invalid children with the following errors:
| Id | Sch_UndeclaredAttribute |
| Description | The 'uri' attribute is not declared. |
| XPath | /c:chartSpace[1]/c:chart[1]/c:extLst[1]/c:ext[1] |
| Part URI | /ppt/charts/chart1.xml |
| NamespacesDefinitions | undefined |
| Id | Sch_InvalidElementContentExpectingComplex |
| Description | The element has invalid child element 'http://schemas.microsoft.com/office/drawing/2017/03/chart:dataDisplayOptions16'. List of possible elements expected: http://schemas.microsoft.com/office/drawing/2017/03/chart:dispNaAsBlank. |
| XPath | /c:chartSpace[1]/c:chart[1]/c:extLst[1]/c:ext[1] |
| Part URI | /ppt/charts/chart1.xml |
| NamespacesDefinitions | undefined |
Expected behavior
I expect the Validator report that the elements are valid.