Implement support for cell references to columns and rows, e.g. $1:$2, A:D, etc.

Currently, CellSelection.SetValue throws ParseException, and CellSelection.SetValueAsFormula throws InvalidOperationException. 

Introduce calculation chain functionality. This will provide a better mechanism for handling dependent expressions.

Currently, the numbers in a CSV file are parsed as numbers, and the leading zeros are lost. In MS Excel, leading zeros could be preserved when the values are imported as text using the more sophisticated text import wizard (http://www.upenn.edu/computing/da/bo/webi/qna/iv_csvLeadingZeros.html ).

Workaround: The values could be extracted using a third-party (or custom) CSV parser, and inserted manually into the model, using CellSelection.SetValueAsText method (http://docs.telerik.com/devtools/document-processing/libraries/radspreadprocessing/working-with-cells/cell-value-types.html ).

IFERROR returns a value you specify if a formula evaluates to an error; otherwise, returns the result of the formula.

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

Implement support for form controls (Button, Combo Box, Check Box, Spin Button, List Box, Option Button, Group Box, Label, Scroll Bar).

Add support for strikethrough font effect for cell formatting. Currently this is not supported by the model and is omitted on import.

CellSelection.SetValue method causes memory leak of CellReferenceRangeExpression objects in some cases when cell value is referenced by formulas. The memory leak is small, but the remaining CellReferenceRangeExpression continue to listen to some events, causing performance issues when their number become large - the time to set the value increases with each set.

Provide the ability to work with images in headers/footers of a worksheet. Note that large images put in headers are visualized as watermarks on printing/exporting to PDF.
Watermark in Excel: https://support.office.com/en-us/article/add-a-watermark-in-excel-a372182a-d733-484e-825c-18ddf3edf009
 

Add support for manual calculation option, which allows not to recalculate all the formulas on value change, but on manual request. 

MS Excel supports this feature in Formulas -> Calculation -> Calculation Options, with the following options: Automatic, Automatic Except for Data Tables, Manual.

Provide the customers with the ability to export workbooks to HTML files.

Provide an API used to recalculate all formulas in the document similar to the Excel Interop Calculate function

At this point, XlsFormatProvider doesn't support images and they are not imported into Workbook while reading an .xls file.

Introduce support for Implicit Intersection Operator '@'.

The cell contains the following data in OOXML:

<f>SUM(1,2,3)</f> - The formula
<v>6</v> - the calculated value

The formula value is imported, but the calculated value is skipped. The feature will be useful if Manual calculation option is supported: https://feedback.telerik.com/Project/184/Feedback/Details/191275-spreadsheet-add-support-for-different-calculation-options-automatic-or-manual

Removing/adding rows/columns inside a worksheet requires all the data after them to be translated according to the change. This operation is slow and affects editing performance.

Add support for images embedded in cells.

Similar to clicking "Place in Cell' in MS Excel which embeds the floating image into the cell:

 

Alternative: Floating Images

It would be beneficial for the clients if every cell has this "cached value" even if the formula can't be evaluated for some reason with the SpreadProcessing - no need for recalculation, just reading the value. It should read the last values while the document was being saved at the originator.

Getting a method like "GetCachedValueString ..." , ideal with the same formatting used for the cell and localization, would be helpful. 

For all characters which cannot be represented in XML as defined by the XML 1.0 specification, the characters are escaped using the Unicode numerical character representation escape character format _xHHHH_, where H
represents a hexadecimal character in the character's value. This is dedined in the OpenXML specification in 22.9.2.19 ST_Xstring (Escaped String).

Currently this causes the following issues:

- Documents conaining such characters are imported incorrectly, e.g. <si><t>_x001B_</t></si> is imported as the plain text _x001B_

- ArgumentException with clarification similar to "' ', hexadecimal value 0x1B, is an invalid character." is thrown when trying to export such documents. Example code to reproduce:

            Workbook workbook = new Workbook();
            Worksheet worksheet = workbook.Worksheets.Add();

            CellSelection selection = worksheet.Cells[1, 1]; //B2 cell
            selection.SetValue(string.Format("Error Value: {0} ", Encoding.ASCII.GetString(new byte[] { 27 })));

            string fileName = @"D:\temp\SampleFile.xlsx";
            IWorkbookFormatProvider formatProvider = new XlsxFormatProvider();
            using (FileStream output = new FileStream(fileName, FileMode.Create))
            {
                formatProvider.Export(workbook, output);
            }

Formulas like =0.0001/10 or formulas that produce small values results in 0 instead of exponential numbers.


Available in LIB version: 2017.1.313

Some of the leftmost borders are omitted when exported to PDF.