Moving Pages

I thought I'd draw attention to a desire of mine for ikiwiki. I'm no power-user, and mostly I do fairly simple stuff with my wiki.

However, I would like the ability (now) to rename/move/delete pages. As part of having a genealogy wiki, I've put name and dates of birth/death as part of the title of each article (so to avoid cases where people have the same name, but are children/cousins/etc of others with that name). However, some of this information changes. For instance, I didn't know a date of death and now I do, or I had it wrong originally, or it turns out someone is still alive I didn't know about. All of these cases leave me with bad article titles.

So, I can go ahead and move the file to a new page with the correct info, orphan that page, provide a link for the new page if desired, and otherwise ignore that page. But then, it clutters up the wiki and serves no useful purpose.

Anyway to consider implementing rename/move/delete ? I certainly lack the skills to appreciate what this would entail, but feel free to comment if it appears impossible, and then I'll go back to the aforementioned workaround. I would prefer simple rename, however.

Thanks again to Joey for putting ikiwiki together. I love the program.

Kyle=

Took a bit too long, but done now. --Joey

The MediaWiki moving/renaming mechanism is pretty nice. It's easy to get a list of pages that point to the current page. When renaming a page it sticks a forwarding page in the original place. The larger the size of the wiki the more important organization tools become.

I see the need for:

a new type of file to represent a forwarding page
a rename tool that can
- move the existing page to the new name
- optionally drop a forwarding page
- optionally rewrite incoming links to the new location

Brad

This could be implemented through the use of an HTTP redirect to the new page, but this has the downside that people may not know they're being redirected.

This could also be implemented using a combination of raw inline and meta to change the title (add a "redirected from etc." page. This could be done with a plugin. A redirect page would be [[!redirect page="newpage"]]. But then if you click "edit" on this redirect page, you won't be able to edit the new page, only the call to redirect. --Ethan

I'm going to try to run through a full analysis and design for moving and deleting pages here. I want to make sure all cases are covered. --Joey

UI

The UI I envision is to add "Rename" and "Delete" buttons to the file edit page. Both next to the Save button, and also at the bottom of the attachment management interface.

The attachment(s) to rename or delete would be selected using the check boxes and then the button applies to all of them. Deleting multiple attachments in one go is fine; renaming multiple attachments in one go is ambiguous, and it can just error out if more than one is selected for rename. (Alternatively, it could allow moving them all to a different subdirectory.)

The Delete buttons lead to a page to confirm the deletion(s).

The Rename buttons lead to a page with a text edit box for editing the page name. The title of the page is edited, not the actual filename.

There will also be a optional comment field, so a commit message can be written for the rename/delete.

Note that there's an edge case concerning pages that have a "/" encoded as part of their title. There's no way for a title edit box to differentiate between that, and a "/" that is instended to refer to a subdirectory to move the page to. Consequence is that "/" will always be treated literally, as a subdir separator; it will not be possible to use this interface to put an encoded "/" in a page's name.

Once a page is renamed, ikiwiki will return to the page edit interface, now for the renamed page. Any modifications that the user had made to the textarea will be preserved.

Similarly, when an attachment is renamed, or deleted, return to the page edit interface (with the attachments displayed).

When a page is deleted, redirect the user to the toplevel index.

Note that this design, particularly the return to the edit interface after rename, means that the rename button can only be put on the page edit ui. It won't be possible to put it on the action bar or somewhere else. (It would be possible to code up a different rename button that doesn't do that, and use it elsewhere.)

Hmm, unless it saves the edit state and reloads it later, while using a separate form. Which seems to solve other problems, so I think is the way to go.

SubPages

When renaming foo, it probably makes sense to also rename foo/Discussion. Should other SubPages in foo/ also be renamed? I think it's probably simplest to rename all of its SubPages too.

(For values of "simplest" that don't include the pain of dealing with all the changed links on subpages.. as well as issues like pagespecs that continue to match the old subpages, and cannot reasonably be auto-converted to use the new, etc, etc... So still undecided about this.)

When deleting foo, I don't think SubPages should be deleted. The potential for mistakes and abuse is too large. Deleting Discussion page might be a useful exception.

TODO: Currently, subpages are not addressed.

link fixups

When renaming a page, it's desirable to keep links that point to it working. Rather than use redirection pages, I think that all pages that link to it should be modified to fix their links.

The rename plugin can add a "rename" hook, which other plugins can use to update links &etc. The hook would be passed page content, the old and new link names, and would modify the content and return it. At least the link plugin should have such a hook.

After calling the "rename" hook, and rendering the wiki, the rename plugin can check to see what links remain pointing to the old page. There could still be some, for example, CamelCase links probably won't be changed; img plugins and others contain logical links to the file, etc. The user can be presented with a list of all the pages that still have links to the old page, and can manually deal with them.

In some cases, a redirection page will be wanted, to keep long-lived urls working. Since the meta plugin supports creating such pages, and since they won't always be needed, I think it will be simplest to just leave it up to the user to create such a redirection page after renaming a page.

who can delete/rename what?

The source page must be editable by the user to be deleted/renamed. When renaming, the dest page must not already exist, and must be creatable by the user, too.

lWhen deleting/renaming attachments, the allowed_attachments PageSpec is checked too.

RCS

Three new functions are added to the RCS interface:

rcs_remove(file)
rcs_rename(old, new)
rcs_commit_staged(message, user, ip)

See rcs updates needed for rename and remove.

conflicts

Cases to consider:

Alice clicks "delete" button for a page; Bob makes a modification; Alice confirms deletion. Ideally in this case, Alice should get an error message that there's a conflict. Update: In my current code, alice's deletion will fail if the file was moved or deleted in the meantime; if the file was modified since alice clicked on the delete button, the modifications will be deleted too. I think this is acceptable.
Alice opens edit UI for a page; Bob makes a modification; Alice clicks delete button and confirms deletion. Again here, Alice should get a conflict error. Note that this means that the rcstoken should be recorded when the edit UI is first opened, not when the delete button is hit. Update: Again here, there's no conflict, but the delete succeeds. Again, basically acceptible.
Alice and Bob both try to delete a page at the same time. It's fine for the second one to get a message that it no longer exists. Or just to silently fail to delete the deleted page.. Update: It will display an error to the second one that the page doesn't exist.
Alice deletes a page; Bob had edit window open for it, and saves it afterwards. I think that Bob should win in this case; Alice can always notice the page has been added back, and delete it again. Update: Bob wins.
Alice clicks "rename" button for a page; Bob makes a modification; Alice confirms rename. This case seems easy, it should just rename the modified page. Update: it does
Alice opens edit UI for a page; Bob makes a modification; Alice clicks rename button and confirms rename. Seems same as previous case. Update: check
Alice and Bob both try to rename a page at the same time (to probably different names). Or one tries to delete, and the other to rename. I think it's acceptible for the second one to get an error message that the page no longer exists. Update: check, that happens
Alice renames a page; Bob had edit window open for it, and saves it afterwards, under old name. I think it's acceptible for Bob to succeed in saving it under the old name in this case, though not ideal. Update: Behavior is the same as if Alice renamed the page and Bob created a new page with the old name. Seems acceptable, though could be mildly confusing to Bob (or Alice).
Alice starts creating a new page. In the meantime, Bob renames a different page to that name. Alice should get an error message when committing; and it should have conflict markers. Ie, this should work the same as if Bob had edited the new page at the same time as Alice did. Update: That should happen. Haven't tested this case yet to make sure.
Bob starts renaming a page. In the meantime, Alice creates a new page with the name he's renaming it to. Here Bob should get a error message that he can't rename the page to an existing name. (A conflict resolution edit would also be ok.) Update: Bob gets an error message.
Alice renames (or deletes) a page. In the meantime, Bob is uploading an attachment to it, and finishes after the rename finishes. Is it acceptible for the attachment to be saved under the old name? Update: Meh. It's certianly not ideal; if Bob tries to save the page he uploaded the attachment to, he'll get a message about it having been deleted/renamed, and he can try to figure out what to do...
I don't know if this is a conflict, but it is an important case to consider; you need to make sure that there are no security holes. You dont want someone to be able to rename something to /etc/passwd. I think it would be enough that you cannot rename to a location outside of srcdir, you cannot rename to a location that you wouldn't be able to edit because it is locked, and you cannot rename to an existing page.

Well, there are a few more cases (like not renaming to a pruned filename, and not renaming from a file that is not a known source file or is locked), but yes, that's essentially it.

PS, the first thing I do to any web form is type /etc/passwd and ../../../../etc/passwd into it. --Joey