For the add columns buttons: simple process to identify the column numbers of new columns.

 

Nothing complicated.  Plan on a column number that is the sum of the column numbers before and after, then divide by 2.

Except for new column at the end.  That one is last column number + 1.

Setting and related checkbox to show/hide the interface for row/column maintenance

Hidden by default

Visible on demand

Basic rendering of sheets working A-1 for 1 or more cells (varying number of rows and columns)

 

The basic process to create a new tiddly sheet also creates the tiddler(s) supporting that sheet

 For a tiddly sheet to function, we need a way to identify the row and column position of each cell, and to alter these positions when adding a row or column of cells, when deleting rows or columns, moving rows/columns, and swapping cells.

Maybe other things I'm not thinking of just yet.

I just firmed up a little the process of adding new TiddlySheet instances, and setup the process to create a supporting tiddler, a tiddler referenced by the TiddlySheet.  That reference as a standard field in the TiddlySheet.

2 Screenshots:

Advanced Search tiddler showing there aren't any supporting tiddlers in existence yet, and the TiddlySheets manager tiddler, before creating a new tiddly sheet.

Same tiddlers showing the results after pressing the "+" button, and the new tiddly sheet automatically opened at the bottom of the story river.

Next task on deck: upon creation of new tiddly sheet, set it up to start out with one cell (one row, one column).

"TiddlySheets Manager": first version of sidebar tab to manage TiddlySheet tiddlers

 

Update

• Just started: formalizing the design for storage of the various things for a TiddlySheet.
• Adding columns and rows: "+" text markers (for the eventual interface and functionality) replaced with buttons (just the cosmetic setup for now)
• Played around with simple formatting of table, rows, columns, cells, just to start chewing on eventual apperance of TiddlySheets and the possibility of having configuration settings for some things.

First prototype of a TiddlySheet

Nothing fancy to start.

Just setup TiddlyWiki / HTML / CSS code to pull together a simple table, along with simple structure to show mock-up of buttons to add columns and add rows to a tiddly sheet.

Tentative plan is to eventually have ability to toggle between various modes, like "view", "data editing" (to just edit content), and "table editing" (to adjust the table in whatever way, including adding columns, adding rows, swapping cells in the sheet).  Something lke that.