When the column width is not an integer number, but a decimal fraction one, the width which is exported is not calculated correctly. 

For example, if there is a cell with some text and its column's width is autofit, it's exported with different actual width.

In addition, if the exported xlsx file is imported back in the Spreadsheet, the column width is a bit different from the one which was exported (only for the first export-import roundtrip).

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.

The MATCH function searches for a specified item in a range of cells and returns the relative position of the item found in this range.

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/CustomFunctions

Available in R3 2017 Official Release Version

Comparison operators (equal '=', not equal '<>') doesn't work as expected with references to empty cells. For example, expressions of type '=IF(A1="", TRUE, FALSE)' are evaluated to false when A1 cell is empty. 

In MS Excel, such expression is evaluated to TRUE if the cell is empty - i.e. empty cell value is considered equal to an empty string "".

Workaround: Use ISBLANK function if possible. Its results are consistent with MS Excel.

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

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.

One should be able to set the axis titles in the code. The attached images show an example of the exported document opened in Excel. 

Implement text orientation for cell content import/export from/to XLSX format

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

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

From the OOXML Specification: A comment is a rich-text note that is attached to and associated with a cell, separate from other cell content.

In Office 365 there are two types of comments:

• Comments/Notes
• Threaded Comments

This item applies to Comments/Notes only.

For Threaded Comments, please follow: SpreadProcessing: Comments (Threaded Comments)

Some functions are exported from Excel with the _xlfn. prefix as compatibility measure with older versions of MS Excel (future functions, see here https://msdn.microsoft.com/en-us/library/dd907480(v=office.12).aspx , https://support.office.com/en-ca/article/Issue-An-xlfn-prefix-is-displayed-in-front-of-a-formula-882f1ef7-68fb-4fcd-8d54-9fbb77fd5025 )

RadSpreadProcessing do not support these and the spreadsheet treats the function as not supported even when it is.

Example:

    <row r="1" spans="2:2" x14ac:dyDescent="0.25">
      <c r="B1" t="b">
        <f>_xlfn.ISFORMULA(C2)</f>
        <v>0</v>
      </c>
    </row>


This could be observed with the ISFORMULA function.

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.

Implement export to XPS file format.

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

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

If shape extent is declared, the two cell anchor points for the drawing element are ignored. For example if the TwoCellAnchorElement's from and two points declare that the image should be anchored starting from cell A1to F10 and further in the drawing declaration there is defined extents element with image size values, anchor element's points are ignored.