SumSheet examples

Every example is a small working application, open right on the page: what the sheet can do and how it behaves inside someone else’s interface. The core does not compute in them — a stand-in does — so the numbers in the cells mean nothing: watch the behaviour. A real core with real recalculation is in the live example.

It’s worth going through them in order: the first ones answer “how much do I need to write to get a sheet”, then come individual capabilities, and at the end, edge cases like a million rows and running without a screen.

• Minimal sheethow many lines it takes to get a working sheet
• Sheet with the ribbonhow to add our ribbon if you need it
• Embedding into a third-party pagewhat happens to the host page around the sheet: its font, background and scrolling
• A million rowsthe cost of three gestures on a workbook at the limit — scrolling, fill-dragging and zooming: p50 and p95 frame times and calls to the core as numbers, not promises
• Crosshairhighlighting the row and column of the active cell: off by default, enabled with a property
• Read-onlythe workbook is visible but cannot be edited: commands are grayed out with a reason rather than hidden, and editing never starts at all
• Custom headersthe integrator sets the row and column labels, and the header strip width is computed from that text
• Sheet without header stripsthe strips are hidden with a single property, and the sheet itself takes the freed space
• Custom menu itema third-party item in our menu: below the divider, under its owner’s name and with its own command — it cannot pass itself off as ours
• Custom keyboard shortcutthe third-party shortcut fires, while the ones taken by the sheet (Ctrl+D, Ctrl+R, F2, Shift+Space) stay with the sheet — the refusal is visible in words
• Custom languagea language that is not among our three is brought by the page owner: labels are translated, and anything untranslated falls back along a chain instead of disappearing
• Drop a workbook herea third-party document is opened from bytes: the shell carries the file, parsing stays behind the contract seam, and a refusal comes in the words of whoever opened it — on the showcase this is a stub that takes csv, tsv and txt and honestly refuses xlsx
• Two people in one documenttwo frames side by side: move the selection in one and the other shows the remote cursor with a name; the screen says plainly that only windows of this browser are visible
• Assistants drive the sheetup to ten external participants, each in its own process: walking its own column, selecting a region and writing in a total — as intents through the same channel; a refusal of anything beyond that is visible both to it and to the person; if they were not started, the page says so
• Custom eventtwo outward extension points: onCommand delivers any intent of the surface (ours and third-party), onGesture the cost of a finished gesture as numbers
• Hyperlinka link is a cell property: one core operation sets it together with the text, removes it leaving the text, and lists the links of the sheet itself
• Find and replacesearch is one request, replace is two, and the first does not change the workbook: the core computes a plan of edits, and the same path as typing writes them
• Notessix comment actions through one contract operation — list, create, delete, reply, undo, redo; the core names the text, the number, and the normalized address
• Sheet outlineeight actions — one operation: the shell names the range, axis and action, and the core computes the levels and what to hide
• Page layoutwhere a page break falls — the only SDK method that asks and changes nothing; printing itself is done by the host, and that is a boundary, not a gap
• Allow editing rangessix of the ten intents the operation has: the password goes behind the contract seam and never comes back — only the protection method comes back
• Workbook linksa formula computes from another workbook: the list of links, their state and the source address come from the core, and the window owner opens the workbook
• Headlessa workbook is opened, edited and read from Node — without a single call to the DOM

Next

• How the sheet works inside — Architecture.
• What you can call today — the Compute Contract reference.