Wiki Safety Belt

Oxfam users have reported pain regarding collaborative authoring on wiki pages. They are have examples of people losing their edits (in obviously a mysterious way), with people resorting to weird worarounds.

This proposal comes from Duncan Booth for a very near-term fix.

Proposal

Put a “safety belt” in the page that notices, upon save, that the wiki page was edited by someone else since the start of your editing.

Out of Scope

The key to this proposal is to do something immediate that doesn’t require heavy analysis and funding. As an example, something that could be done in less than 4 hours. Thus the following are not in scope:

• Any other content except a wiki page
• Locking
• Versioning
• History
• Diff

Details

• When an author clicks “Edit” on a wiki page and gets back the form for editing, include a hidden field that contains the modification date/time of the previous edit.
• When the author saves their changes, compare that date-time to the modification date-time just before saving.
• If the wiki pages has a more recent modification date-time, trigger a form error.
• Return the editing form, with:
  • A form error saying the page has been modified since you started editing. Provide the first and last name of the person that did the editing.
  • Include any unsaved changes to any of the fields, particularly the text field.
  • Show a widget that asks if they want to overwrite the previous person’s edits.
  • An updated hidden field with the date-time of the more recent edit.
• Clicking save then submits and overwrites that person’s edits, unless it had been modified again while the form error was being processed. If so, repeat error process.

Alternatives

We could choose to invest a bit more money and throw some AJAX at this, to improve the user experience.

For example, clicking the “save” button could issue an AJAX request checking to see if it had changed, then popping up a dialog showing the name of the more-recent modifier. This would be inconsistent with other form-saving error displays, so probably not worth it.

We could let the person know sooner by pinging the server every 15 seconds and showing a message. This is notably more complex and increases the load on the server.