Allow Excel Javascript API to check for merge cells. Currently it can only merge/unmerge cells but can not check the cell status.

I have a number of exported XLL functions with optional arguments. When calls to these functions are made from Excel, the optional arguments are populated with a default value (e.g. zero for doubles). For functions where the default value (for example zero for doubles) is a potentially-valid input for an optional parameter, there is no easy way to "tell" when it should be interpreted as default or a valid input.

It seems to me this could be handled by adding some additional metadata to the xlfRegister function call.

Add possibilities to disable screen updating to speed up things (Application.ScreenUpdating)

I would like to be able to access the page layout properties of the document so that I can set the print area.

How to find the dirty cell/cells from excel sheet using Excel Javascript API.

If a cell is edited by value / formula / format, that became dirty. So I need to find, what are all the cells are dirty(edited) from range of cells.

Please refer this stack over flow link - https://stackoverflow.com/questions/50817709/find-the-dirtyedited-cell-cells-from-excel-sheet-using-excel-javascript-api

In Excel API, I can't choose cells based if they have formulas or values.

In VBA, I can do that by using Range.SpecialCells method. Also, I can specify if I want to get only text values, numbers, errors and/or booleans.

Please, support this for Excel JavaScript API, because currently, I'm looping all the worksheet's used range rectangle to get the values, and my loops spend a lot of time skipping blank cells.

Use a method like numberFormat that takes a table to format the font colors, weights ... of the data in a table.

For Example :

const sheet = context.workbook.worksheets.getItem("Sample");
const formats = [
["red", "red"],
["red", "red"],
["red", "red"]
];

const range = sheet.getRange("D3:E5");
range.XXX = formats;

I would like to see the VBA environment support in statements.
E.g.:
If X in (1,5,7)
or
If Y in ("Open","Ready")

I know we can use case statements, but sometimes the code can become a lot more concise with an In statement.

When designing and developing a VBA the developer can be reasonably sure that all the Excel APIs that are required for the project are available.
If the developer wants to convert an existing VBA project to Excel-JS there is currently no easy way to find out if the VBA APIs being used exist in the restricted subset of Excel-JS APIs.

It would be extremely useful to have a tool that analysed a VBA project and produced a unique list of all the VBA OM calls.

A frequent scenario when creating reports is to create in advance ranges containing things like header, detail and totals formats somewhere and then when creating the report (which may have a variable number of columns and detail lines etc) use the predefined range formats to set the report formats using the stored range formats.
Its difficult to do this copying entire sheets or trying to set all the imdividual formats of a cell by trial and error using code.

When multiple workbooks are open Excel treats their worksheets in a similar way across all open workbooks: you just qualify range references with the workbook name.
Excel-JS should behave the same way when the user opens multiple workbooks.

We can read/update custom properties in Word. It would be great if we can have similar function in Excel also.

It would be extremely helpful in certain cases to prevent user to interact with the sheet/workbook while some action in the task pane is required or when some process is running (e.g. when some complex sheet changes are being performed - formatting, inserting columns, inserting data, charts....).

Currently when you lock cells and enable worksheet protection, you cannot change anything in the cells.

A VERY common and basic need is to allow editing of certain cell values but maintain or lock things like conditional formatting.

Writing a row to a sheet that has autofilters (CTRL+Shift+L) on can be difficult / error prone. Please provide a way through the Office-js API to clear/remove the autofilters on a sheet.