%META:TOPICINFO{author="PeterThoeny" date="1042362854" format="1.0" version="1.17"}%
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---# Managing Topics

_Browser-based rename, move, and delete for individual topics_

---++ Overview

You can use browser-based controls to change a topic's name, move it to another TWiki web, or delete it to a hidden =Trash= web.

---++ How to Rename/Move/Delete a Topic

	1. *Click* on ==[More]== (bottom right of page) on the topic to be changed, then, in the new screen, on ==[Rename/move]==. You can now rename and/or move/delete in one operation:
	1. *Move/Delete:* Select the target web if other than the current web - choose =Trash= to [[#DeleteTopic][delete a topic]].
	1. *Rename:* Enter the new topic name - default is current name <br />
	  %X% *NOTE:* You'll be warned if any of the topics to be affected are locked (being edited), or if there is a name conflict.
	1. *Prevent updates* by unchecking individual items on the list of referring links - these topics will NOT to be updated with the new name (by default, all referring links will be updated).
	1. *Click* on ==[Rename/Move]==: the topic will be renamed and links to the topic updated as requested.
		* If any of the referring pages are locked then they will be listed: you can correct these later by again pressing ==[Rename/Move]==.
		* %H% There is a __Put back__ feature that allows you to undo a ==Rename/Move/Delete== - an instruction line and undo link will appear at the bottom of the modified topic. This allows you to revert from the _last modification only_.

#DeleteTopic
---++ Deleted Topics: How to Clear the Trash

Deleted topics are moved to a special ==Trash== web - they are NOT physically erased from the server. All webs share =Trash= - in case of a name conflict with a topic already =Trash=, the user is alerted and asked to choose a new name.

The =Trash= web should be be cleared periodically, by archiving (saving) the text and RCS files if required (recommended), then deleting them from the =Trash= directory. 

	* %X% This can only be done from on the server, not through the browser. 
		* %T% Since simple FTP access to the ==Trash== directory is all that's required for maintenance, it's possible to grant =Trash= admin privileges to multiple users, while strictly limiting server access. 

---++ Redirecting from an Old Topic

You can use TWikiMetaData to place a command in the %TWIKIWEB%.WebTopicViewTemplate and %TWIKIWEB%.WebTopicNonWikiTemplate that will indicate that a topic has been moved by searching for the tag %<nop>META:TOPICMOVED{...}%. Customize something like this:

<blockquote style="background-color:#f0f0f0">
<verbatim>
%<nop>METASEARCH{type="topicmoved" web="%WEB%" topic="%TOPIC%" 
title="This topic used to exist and was moved to: "}%
</verbatim>
</blockquote>

---++ How Rename/Move Works

	1. %<nop>SEARCH%, with a special template, finds and displays all occurrences of the topic name in other topics, site-wide. These referring links are by default automatically changed to the new topic and/or web name. This includes relevant TWikiMetaData definitions.
		* User can omit one or more topics from the update list by unchecking them.
		* =&lt;pre&gt;= and =&lt;verbatim&gt;= are honoured - no changes are made to text within these areas.
	2. The topic is moved (if locks allow).
	3. References are changed (locks and permissions permitting).
	4. Any referring topics that can't be changed due to locks are listed - user can take note and change them at another time.

---+++ How Referring Topics Are Found

Referring topics are found using the %<nop>SEARCH% variable - see the template ==searchrenameview.tmpl==. First, matching topics in the current web are listed - matches are to ==topic==.  Next, all webs (including the current one) are listed that match ==web.topic==. Because %<nop>SEARCH% is used, webs marked in WebPreferences as =NOSEARCHALL= will not show up in the search for references to the =topic= being changed.

Changed references are kept are as short as possible, ex: =topic= is used in preference to =web.topic=.

---+++ Effect of User Access Settings

User permissions affect the Rename function in various ways. To rename a topic, you need both ==ALLOWTOPICCHANGE== and ==ALLOWTOPICRENAME== permission for that topic. To alter referring topics, you need change permission. See TWikiAccessControl for information on setting up access permissions.

---++ Special Considerations

Consider carefully whether to make browser-based *Rename/Move/Delete* widely available, or to restrict it to an administrator/moderator group. Allowing all users to easily manipulate topics can be extremely useful in refactoring a busy web or site. However, there are at least two significant potential drawbacks to take into account: 
	* When referring links are updated, the modified topics appear in WebChanges, creating the impression that editorial changes were made. This can undermine the usefulness of WebChanges.
	* Due to [[#RenameLimitations][current limitations]], fairly heavy use of Rename/Move/Delete functions can lead to an accumulation of minor technical problems (ex: broken links) and usability issues (ex: user confusion). If Rename... is used heavily, these negatives will obviously increase, in number and effect.

Ultimately, the size, objectives, and policies of your TWiki site, the real-world behavior of your user group, and most importantly, the initial TWiki site management leadership, will determine the most effective implementation of this feature, and the success of the site overall.

#RenameLimitations
---++ Known Issues

*Rename/Move* is fairly complicated due to the dynamic generation of links. Ideally, it would be possible to run the required part of rendering in a way that would allow identification of the text to be changed. Unfortunately, these hooks don't exist in TWiki at present.  Instead, %<nop>SEARCH% is used with a special template to show the text to be changed, and the selected topics are then altered. One drawback is that =search= can show matches that will not be updated due to case differences. Other mismatches with actual rendered output are also possible as the approaches are so different.

The following shows some limitations of square bracket processing.

<blockquote style="background-color:#f0f0f0">
<verbatim>
[[Old Topic]]  => [[NewTopic][Old Topic]]
[[old topic]]  => [[NewTopic][old topic]]
[[old t opic]] => not changed
[[OldTopic]]	=> [[NewTopic]]
</verbatim>
</blockquote>

-- Main.MikeMannix - 27 Dec 2001
%META:TOPICMOVED{by="MikeMannix" date="999329908" from="TWiki.RenameTopic" to="TWiki.ManagingTopics"}%
