Item5805: Trunk doesn't work with ShorterUrlCookbook

When I merged the fix of Item5382 to trunk, I attempted to test it, then I realized that TWiki:TWiki/ShorterUrlCookbook doesn't work with trunk. Wen used, it leads to a "Not Found" error (message generated from TWiki::UI::handleRequest: it searches for an entry within $TWiki::cfg{SwitchBoard} and if none is find, error!).

I didn't test yet, but I suspect that it happens cause $req->action() is empty (or with the web's name).

-- TWiki:Main/GilmarSantosJr - 22 Jul 2008

I changed overall path handling a little, so I could achieve more flexiblity:

• It's possible to keep using regular bin scripts (view, edit, save, etc), so legacy/alien apache auth works as always wordek
• CLI interface is more stable
• It's possible to eliminate all regular bin scripts and use only twiki_cgi.pl (legacy/alien apache auth could work by using Location directives instead of Files)
• It's possible to replace regular bin scripts by twiki_cgi.pl and keep those needed to legacy/alien apache auth
• All items above works in the traditional way and with TWiki:TWiki.ShorterUrlCookbook

I have some assumptions:

• twiki_cgi.pl is always used in one of the following ways:
  • ScriptAlias /twiki/bin /path/to/twiki/bin/twiki_cgi.pl (map bin to twiki_cgi.pl, so the action is the first component of path_info)
  • Alias /twiki /path/to/twiki/bin/twiki_cgi.pl (ShorterUrl. First component of path_info is not an action. Same constraints of ShorterUrl applies)
• ShorterUrl should work with both twiki_cgi.pl and view (so, who already uses view doesn't need to change config)
• Regular script are always used with ScriptAlias /twiki/bin /path/to/twiki/bin (the traditional way: many entry points)

So, changes were:

• regular bin scripts define TWIKI_ACTION environment variable with its name
• twiki_cgi.pl ensure there's no TWIKI_ACTION environment variable
• CGI engine tests if TWIKI_ACTION is defined:
  • If it is, then set $req->action (a regular script was used. With SorterUrl or not)
  • If not, then check if the first component of PATH_INFO corresponds to an action, I mean, check if exists $TWiki::cfg{SwitchBoard}{comp} (twiki_cgi.pl was called. With ShorterUrl or not)
    • If it exists, then set action to it and remove it from PATH_INFO (no ShorterUrl)
    • If not, assume that action is view (ShorterUrl)

Corner cases:

• If PATH_INFO is not defined or empty
  • And TWIKI_ACTION is defined, then default web and topic is used (Main.WebHome in most cases)
  • And TWIKI_ACTION not defined, then assume that action is view

The reason to keep regular bin scripts is the use of legacy/alien apache auth and CLI interface. I think this solution is flexible enough. Unit tests can keep using path_info as it was always used.

Please, verify this and give feedback.

-- TWiki:Main.GilmarSantosJr - 10 Aug 2008

Yes, that makes sense. It has the added unwritten benefit that by adding TWIKI_ACTION to $TWiki::cfg{SafeEnv}, then will provide the action name.

-- TWiki:Main.CrawfordCurrie - 11 Aug 2008

I sent this to twiki-dev mailing list, but it's cool to also document here:

I didn't understand this unwritten benefit. Action name is available to TWiki from $twiki->{request}->action() and to plugins from TWiki::Func::getCgiQuery()->action(). The environment variable is used only by regular scripts (not twiki_cgi.pl) and CGI/CLI engines. The portable way is to check action() from TWiki::Request.

-- TWiki:Main.GilmarSantosJr - 11 Aug 2008

Crawford gave an excellent reason to add TWIKI_ACTION to $TWiki::cfg{AccessibleENV}:

> The portable way is to check action() from TWiki::Request.

From code, yes. But now template and topic authors can write:

%ENV{TWIKI_ACTION}%

e.g.

%INCLUDE{"OtherTopicVersion"}%

to include OtherTopicviewVersion, OtherTopicpreviewVersion etc etc.

(if TWIKI_ACTION is added to $TWiki::cfg{AccessibleENV}, that is)

I made TWiki::Request::action() set $ENV{TWIKI_ACTION}, so it's available to TWiki core and plugins no matter what engine is in use.

-- TWiki:Main.GilmarSantosJr - 16 Aug 2008