Add pivot table with limitations

[mikez]

worksheet.addPivotTable(configuration);

Note: Pivot table support is in its early stages with certain limitations, including:

• No support for reading xlsx documents with existing pivot tables (writing is supported).
• Pivot table configurations must consist of one "value" item and use the sum metric.
• Only one pivot table can be added for the entire document.

Example usage

const workbook = new Excel.Workbook();

const worksheet1 = workbook.addWorksheet('Sheet1');
worksheet1.addRows([
  ['A', 'B', 'C', 'D', 'E'],
  ['a1', 'b1', 'c1', 4, 5],
  ['a1', 'b2', 'c1', 4, 5],
  ['a2', 'b1', 'c2', 14, 24],
  ['a2', 'b2', 'c2', 24, 35],
  ['a3', 'b1', 'c3', 34, 45],
  ['a3', 'b2', 'c3', 44, 45],
]);

const worksheet2 = workbook.addWorksheet('Sheet2');
worksheet2.addPivotTable({
  // Source data: entire sheet range
  sourceSheet: worksheet1,
  // Pivot table fields: via header row in `worksheet1`
  rows: ['A', 'B'],
  columns: ['C'],
  values: ['E'], // Exactly 1 field
  metric: 'sum', // Metric: 'sum' only
});

[Siemienik]

Hello @mikez , Thank you for the latest changes, I'm really happy that Exceljs has possibility to gain new feature even with limitations.
I added few comments, I would be glad for answering that 😄

Good job and I love the direction when it comes. 🥇

[Siemienik]

Would It be enabled to add partially configured pivot table without for instance rows set?

[mikez]

At this time, the code doesn't support that. You need at least one item in each of {rows, columns, values}.
However, this could be a potential feature down the road if it is requested.

[Siemienik]

Does it always start from row 1?

[mikez]

I made the simplifying assumption that the source data is represented by the entire sheet, with the first row representing the header. Do you think this assumption is too simplistic and won't capture 95% of the cases?

[Siemienik]

What will happen if someone remove the pivot table from one of these places, or overwrite one of them?
What do you think about making wb.workbook.pivotTables a getter returning pivottables from all worksheets? Or .. a function?
Can it attach one pivotTable to multiple sheets?

[mikez]

What will happen if someone remove the pivot table from one of these places, or overwrite one of them?

@Siemienik It seems you're pointing at the mutability of worksheet.pivotTables and worksheet.workbook.pivotTables and concerns for that clients might mutate this. If you think this type of safety is needed and consistent with elsewhere in ExcelJS, we can definitely make it a getter. I'll take your advice here.

Can it attach one pivotTable to multiple sheets?

At this time, I intend for there to be at most one pivotTable in at most one sheet across the entire workbook. The user should not have to mutate worksheet.pivotTables or worksheet.workbook.pivotTables and only access worksheet.addPivotTable.

[Siemienik]

You may try this way:

Suggested change

	${[...range(0, sharedItems.length)].map(index => `<item x="${index}" />`).join('\n ')}
	${sharedItems.map((item, index) => `<item x="${index}" />`).join('\n ')}

[mikez]

Clever. I like this. I will update and force push this.

[mikez]

@Siemienik: I added few comments, I would be glad for answering that 😄

Thank you. Please guide me where I might want to add clarifications to the documentation or comments to make it clearer for other readers.

[Siemienik]

LGTM, thank you for booting up new feature into exceljs 👏

[mikez]

👉 Feedback and discussion here.