Currently, the chart lines support only solid fill for their outlines.

The API should be able to provide a way to move the X-axis away from the 0 value on the Y-axis or to the bottom of the chart when there are negative Y-axis values.

In Excel this can be achieved by right click on the axis, then from the context menu select "Format Axis".  Go to the "Labels" group and then in the "Label position" field select the desired value.

When opening an Xlsx file with conditional formatting I get an Exception:

"System.ArgumentNullException: 'Value cannot be null. (Parameter 'formatting')'

at Telerik.Windows.Documents.Spreadsheet.Model.ConditionalFormattings.ConditionalFormattingDxfRule..ctor(DifferentialFormatting formatting)
   at Telerik.Windows.Documents.Spreadsheet.FormatProviders.OpenXml.Xlsx.Model.Elements.Worksheets.ConditionalFormattingRuleElement.GetRule(DifferentialFormatting formatting)
   at Telerik.Windows.Documents.Spreadsheet.FormatProviders.OpenXml.Xlsx.Model.Elements.Worksheets.ConditionalFormattingRuleElement.OnAfterRead(IXlsxWorksheetImportContext context)
   at Telerik.Windows.Documents.FormatProviders.OpenXml.Model.Elements.OpenXmlElementBase.ReadChildElements(IOpenXmlReader reader, IOpenXmlImportContext context)
   at Telerik.Windows.Documents.FormatProviders.OpenXml.Model.Elements.OpenXmlElementBase.Read(IOpenXmlReader reader, IOpenXmlImportContext context)
   at Telerik.Windows.Documents.FormatProviders.OpenXml.Model.Elements.OpenXmlElementBase.ReadChildElements(IOpenXmlReader reader, IOpenXmlImportContext context)
   at Telerik.Windows.Documents.FormatProviders.OpenXml.Model.Elements.OpenXmlElementBase.Read(IOpenXmlReader reader, IOpenXmlImportContext context)
   at Telerik.Windows.Documents.FormatProviders.OpenXml.OpenXmlImporter`1.ImportPartFromArchive(ZipArchiveEntry zipEntry, PartBase part, IOpenXmlImportContext context)
   at Telerik.Windows.Documents.FormatProviders.OpenXml.OpenXmlImporter`1.Import(Stream input, IOpenXmlImportContext context)
   at Telerik.Windows.Documents.Spreadsheet.FormatProviders.OpenXml.Xlsx.XlsxFormatProvider.ImportOverride(Stream input)
   at WpfApp1.MainWindow.StartExcel() in C:\Users\larse\source\repos\WpfApp1\MainWindow.xaml.cs:line 49"

To quote my colleage: "After dissecting the Excel template file, I have isolated what is causing the issue. If conditional formatting is used to disable cell boarders it results in the error, if the conditional formatting is updated to turn the necessary borders white, instead of disabling the report exports correctly, the following screenshot also explains."

When the cell content overflows the cell width the left cell border is not exported to PDF.

This happens only on import, that is, if the values are created through UI or through the model, it does not happen. A sheet has a formula A which depends on a cell B and this cell also has a reference to another cell C and the formula A is so placed in the sheet so that it will be imported before cell B. When cell C is updated, the value in A will not be recalculated.

The AlternateContent element is used to store content which is not defined by the specification.

Enable the customers to import SVG images and use them in their documents.

Add support for the SUBTOTAL function: https://support.office.com/en-us/article/SUBTOTAL-function-7b027003-f060-4ade-9040-e478765b9939

It computes the subtotal for some ranges, given the code for the subtotal function:

SUBTOTAL(function_num,ref1,[ref2],...)

where function_num is code referring to some of the functions: AVERAGE, COUNT, COUNTA, MAX, MIN, PRODUCT, STDEV, STDEVP, SUM, VAR, VARP.

Note that we should implement the support for all of the above functions. As of now, COUNTA, VAR, VARP are not supported.

Workaround: This could be implemented as a custom function: http://docs.telerik.com/devtools/document-processing/libraries/radspreadprocessing/features/formulas/custom-functions.html , but multiple functions (4 as of now) has to be additionally implemented.

Add support for MID function. MID returns a specific number of characters from a text string, starting at the position you specify, based on the number of characters you specify.

MID(text, start_num, num_chars)

A list of the supported functions is available at http://docs.telerik.com/devtools/document-processing/libraries/radspreadprocessing/features/formulas/functions

This function can be implemented as a custom function. Check the following resources for more details on how to achieve that:

- http://docs.telerik.com/devtools/document-processing/libraries/radspreadprocessing/features/formulas/custom-functions
- https://github.com/telerik/xaml-sdk/tree/master/Spreadsheet/WPF/CustomFunctions

The AutoFitWidth functionality does not take into account the filtering button.

The named ranges are not updated after rows or columns are inserted.

Implement export to XPS file format.

At this point the culture used by RadSpreadProcessing (in the FormatHelper and internally in SpreadsheetCultureHelper) is determined by the current thread culture on startup. Provide ability to:
- to change the culture at runtime. Currently, when the thread culture is changed, RadSpreadProcessing is "stuck" with the original one.
- set this culture independently of the current thread's one.

Introduce support for the WEEKDAY function.

The r attribute of a cell defines the reference the cell is pointing to in a style similar to A1. Setting this attribute is optional but when set to an empty string, it cannot be imported - an ArgumentException is thrown with message "cellName" by the Guard class in NameConverter.ConvertCellNameToIndex().

Here is an example of such a definition:

<row r="1" spans="1:12">
  <c r=""/>
</row>


MS Excel and Libre Office can open such documents.

Add support for ROW function: https://support.office.com/en-us/article/ROW-function-3a63b74a-c4d0-4093-b49a-e76eb49a6d8d?ui=en-US&rs=en-US&ad=US

Examples:

=ROW() returns the row in which the formula appears
=ROW(C10) returns the row of the reference - 10


Workaround: This could be implemented as a custom function: http://docs.telerik.com/devtools/document-processing/libraries/radspreadprocessing/features/formulas/custom-functions.html

Implement NewLine property in the CsvSettings class.