Undo only your own changes in a shared document

How to do it

A shared undo history lets one person's Ctrl+Z wipe out a colleague's paragraph. Tag local edits with an origin and let the undo manager track only that origin. Group fast typing into one undo step, such as all keys within half a second. Undo after an offline period still only touches the person's own changes. Deleting a whole document or record still follows Let people undo or confirm destructive actions.

Examples

TypeScript example

const LOCAL = Symbol('local-edit');
const body = doc.getText('body');
const undo = new Y.UndoManager(body, { trackedOrigins: new Set([LOCAL]), captureTimeout: 500 });

export function typeText(position: number, value: string) {
  doc.transact(() => body.insert(position, value), LOCAL);
}

Python example

from playwright.sync_api import expect

def test_undo_leaves_other_peoples_text(browser):
    first, second = (browser.new_context().new_page() for _ in range(2))
    for page in (first, second):
        page.goto("https://staging.example.com/docs/42")
    first.get_by_role("textbox", name="Document").press_sequentially("one ")
    second.get_by_role("textbox", name="Document").press_sequentially("two")
    first.keyboard.press("Control+z")
    expect(first.get_by_role("textbox", name="Document")).to_have_text("two")

How to check

A test with two browsers types "one" in the first and "two" in the second, then presses undo in the first. The document holds "two" and not "one".

Related rules

• APP-44 Let people undo or confirm destructive actions in Web app interface