Re: [Phpwiki-talk] Diff feature request...

[Steve W. <sw...@pa...>]

On Tue, 18 Sep 2001, Adam Shand wrote:

>
> > I've noticed that the page-edit lock frustrates users, when they do a
> > long edit and it fails.
>
> i've never understood this.  why don't wiki's tell you when you *try* to
> edit a page that someone else is already editing it?  that seems more
> sensible to me then after a page has been being edited for X amount of
> time user should have the option of waiting or breaking the lock.

HTTP is a stateless protocol. That is, you make a connection, get the
page, and disconnect. Compare this to a telnet session, which is stateful.

If Keesha fetches HomePage and starts to edit it, she gets the current
version in the Edit page. Maybe she edits it, maybe not. Maybe she goes
home for the day.

Elmer then wants to edit HomePage. But the Wiki tells him someone else is
editing it so he waits, and waits and waits.

Meanwhile Keesha's computer is crashed overnight by the new "nimbda" worm.
She never gets to save her changes. In fact, now there is a lock on the
file and noone can change it.

This is one of many scenarios possible because HTTP is stateless. The
server has no way of knowing when (if ever) Keesha will save her changes.

WebDAV extends the HTTP with new features to handle collaboration like
this. A WikiWikiWeb, however, is just a quick and dirty solution to
collaboration on content. We don't worry (much) about such fundamental
problems.

If you think the current situation is frustrating, the previous situation
was far far worse: you'd spend a long time making changes to a page, save
those changes, and then come back an hour later and find someone
accidentally saved *their* copy over yours, and all your changes are not
only lost, they are irrecoverable! This is the Lost Update Problem.

Now, at least you can pull your copy from the archive. The irritating
page-edit lock, as it exists now, at least prevents you from losing
everything.

~swain


---
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