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TWiki::Func Module Documentation

Official list of stable TWiki functions for Plugin developers

Description

This module defines official funtions that Plugins and add-on scripts can use to interact with the TWiki engine and content.

Plugins should only use functions published in this module. If you use functions in other TWiki libraries you might impose a security hole and you will likely need to change your Plugin when you upgrade TWiki.

The version of the TWiki::Func module is defined by the VERSION number of the TWiki::Plugins module, currently 1.025. This can be shown by the %PLUGINVERSION{}% variable. The "Since" field in the function documentation refers to the VERSION number and the date that the function was addded.

Functions: CGI Environment

getSessionValue( $key ) ==> $value

Description: Get a session value from the Session Plugin (if installed)
Parameter: $key Session key
Return: $value Value associated with key; empty string if not set; undef if session plugin is not installed
Since: TWiki::Plugins::VERSION 1.000 (27 Feb 2001)

setSessionValue( $key, $value ) ==> $result

Description: Set a session value via the Session Plugin (if installed)
Parameter: $key Session key
Parameter: $value Value associated with key
Return: $result "1" if success; undef if session plugin is not installed
Since: TWiki::Plugins::VERSION 1.000 (17 Aug 2001)

getSkin( ) ==> $skin

Description: Get the name of the skin, set by the SKIN preferences variable or the skin CGI parameter
Return: $skin Name of skin, e.g. "gnu". Empty string if none
Since: TWiki::Plugins::VERSION 1.000 (29 Jul 2001)

getUrlHost( ) ==> $host

Description: Get protocol, domain and optional port of script URL
Return: $host URL host, e.g. "http://example.com:80"
Since: TWiki::Plugins::VERSION 1.000 (7 Dec 2002)

getScriptUrl( $web, $topic, $script ) ==> $url

Description: Compose fully qualified URL
Parameter: $web Web name, e.g. "Main"
Parameter: $topic Topic name, e.g. "WebNotify"
Parameter: $script Script name, e.g. "view"
Return: $url URL, e.g. "http://example.com:80/cgi-bin/view.pl/Main/WebNotify"
Since: TWiki::Plugins::VERSION 1.000 (7 Dec 2002)

getScriptUrlPath( ) ==> $path

Description: Get script URL path
Return: $path URL path of TWiki scripts, e.g. "/cgi-bin"
Since: TWiki::Plugins::VERSION 1.000 (7 Dec 2002)

getViewUrl( $web, $topic ) ==> $url

Description: Compose fully qualified view URL
Parameter: $web Web name, e.g. "Main". The current web is taken if empty
Parameter: $topic Topic name, e.g. "WebNotify"
Return: $url URL, e.g. "http://example.com:80/cgi-bin/view.pl/Main/WebNotify"
Since: TWiki::Plugins::VERSION 1.000 (7 Dec 2002)

getOopsUrl( $web, $topic, $template, $param1, $param2, $param3, $param4 ) ==> $url

Description: Compose fully qualified "oops" dialog URL
Parameter: $web Web name, e.g. "Main". The current web is taken if empty
Parameter: $topic Topic name, e.g. "WebNotify"
Parameter: $template Oops template name, e.g. "oopslocked"
Parameter: $param1 ... $param4 Parameter values for %PARAM1% ... %PARAM4% variables in template, optional
Return: $url URL, e.g. "http://example.com:80/cgi-bin/oops.pl/ Main/WebNotify?template=oopslocked&param1=joe"
Since: TWiki::Plugins::VERSION 1.000 (7 Dec 2002)

getPubUrlPath( ) ==> $path

Description: Get pub URL path
Return: $path URL path of pub directory, e.g. "/pub"
Since: TWiki::Plugins::VERSION 1.000 (14 Jul 2001)

getCgiQuery( ) ==> $query

Description: Get CGI query object. Important: Plugins cannot assume that scripts run under CGI, Plugins must always test if the CGI query object is set
Return: $query CGI query object; or 0 if script is called as a shell script
Since: TWiki::Plugins::VERSION 1.000 (7 Dec 2002)

writeHeader( $query )

Description: Prints a basic content-type HTML header for text/html to standard out
Parameter: $query CGI query object
Return: none
Since: TWiki::Plugins::VERSION 1.000 (7 Dec 2002)

redirectCgiQuery( $query, $url )

Description: Redirect to URL
Parameter: $query CGI query object
Parameter: $url URL to redirect to
Return: none, never returns
Since: TWiki::Plugins::VERSION 1.000 (7 Dec 2002)

Functions: Preferences

extractNameValuePair( $attr, $name ) ==> $value

Description: Extract a named or unnamed value from a variable parameter string
Parameter: $attr Attribute string
Parameter: $name Name, optional
Return: $value Extracted value
Since: TWiki::Plugins::VERSION 1.000 (7 Dec 2002)

getPreferencesValue( $key, $web ) ==> $value

Description: Get a preferences value from TWiki or from a Plugin
Parameter: $key Preferences key
Parameter: $web Name of web, optional. Current web if not specified; does not apply to settings of Plugin topics
Return: $value Preferences value; empty string if not set
Since: TWiki::Plugins::VERSION 1.000 (7 Dec 2002)

getPluginPreferencesValue( $key ) ==> $value

Description: Get a preferences value from your Plugin
Parameter: $key Plugin Preferences key w/o PLUGINNAME_ prefix.
Return: $value Preferences value; empty string if not set
Since: TWiki::Plugins::VERSION 1.021 (27 Mar 2004)

getPreferencesFlag( $key, $web ) ==> $value

Description: Get a preferences flag from TWiki or from a Plugin
Parameter: $key Preferences key
Parameter: $web Name of web, optional. Current web if not specified; does not apply to settings of Plugin topics
Return: $value Preferences flag "1" (if set), or "0" (for preferences values "off", "no" and "0")
Since: TWiki::Plugins::VERSION 1.000 (7 Dec 2002)

getPluginPreferencesFlag( $key ) ==> $flag

Description: Get a preferences flag from your Plugin
Parameter: $key Plugin Preferences key w/o PLUGINNAME_ prefix.
Return: $flag Preferences flag "1" (if set), or "0" (for preferences values "off", "no" and "0", or values not set at all)
Since: TWiki::Plugins::VERSION 1.021 (27 Mar 2004)

getWikiToolName( ) ==> $name

Description: Get toolname as defined in TWiki.cfg
Return: $name Name of tool, e.g. "TWiki"
Since: TWiki::Plugins::VERSION 1.000 (27 Feb 2001)

getMainWebname( ) ==> $name

Description: Get name of Main web as defined in TWiki.cfg
Return: $name Name, e.g. "Main"
Since: TWiki::Plugins::VERSION 1.000 (27 Feb 2001)

getTwikiWebname( ) ==> $name

Description: Get name of TWiki documentation web as defined in TWiki.cfg
Return: $name Name, e.g. "TWiki"
Since: TWiki::Plugins::VERSION 1.000 (27 Feb 2001)

Functions: User Handling and Access Control

getDefaultUserName( ) ==> $loginName

Description: Get default user name as defined in TWiki.cfg's $defaultUserName
Return: $loginName Default user name, e.g. "guest"
Since: TWiki::Plugins::VERSION 1.000 (7 Dec 2002)

getWikiName( ) ==> $wikiName

Description: Get Wiki name of logged in user
Return: $wikiName Wiki Name, e.g. "JohnDoe"
Since: TWiki::Plugins::VERSION 1.000 (7 Dec 2002)

getWikiUserName( $text ) ==> $wikiName

Description: Get Wiki name of logged in user with web prefix
Return: $wikiName Wiki Name, e.g. "Main.JohnDoe"
Since: TWiki::Plugins::VERSION 1.000 (7 Dec 2002)

wikiToUserName( $wikiName ) ==> $loginName

Description: Translate a Wiki name to a login name based on Main.TWikiUsers topic
Parameter: $wikiName Wiki name, e.g. "Main.JohnDoe" or "JohnDoe"
Return: $loginName Login name of user, e.g. "jdoe"
Since: TWiki::Plugins::VERSION 1.000 (7 Dec 2002)

userToWikiName( $loginName, $dontAddWeb ) ==> $wikiName

Description: Translate a login name to a Wiki name based on Main.TWikiUsers topic
Parameter: $loginName Login name, e.g. "jdoe"
Parameter: $dontAddWeb Do not add web prefix if "1"
Return: $wikiName Wiki name of user, e.g. "Main.JohnDoe" or "JohnDoe"
Since: TWiki::Plugins::VERSION 1.000 (7 Dec 2002)

isGuest( ) ==> $flag

Description: Test if logged in user is a guest
Return: $flag "1" if yes, "0" if not
Since: TWiki::Plugins::VERSION 1.000 (7 Dec 2002)

permissionsSet( $web ) ==> $flag

Description: Test if any access restrictions are set for this web, ignoring settings on individual pages
Parameter: $web Web name, required, e.g. "Sandbox"
Return: $flag "1" if yes, "0" if no
Since: TWiki::Plugins::VERSION 1.000 (27 Feb 2001)

checkAccessPermission( $type, $wikiName, $text, $topic, $web ) ==> $flag

Description: Check access permission for a topic based on the TWiki.TWikiAccessControl rules
Parameter: $type Access type, e.g. "VIEW", "CHANGE", "CREATE"
Parameter: $wikiName WikiName of remote user, i.e. "Main.PeterThoeny"
Parameter: $text Topic text, optional. If empty, topic $web.$topic is consulted
Parameter: $topic Topic name, required, e.g. "PrivateStuff"
Parameter: $web Web name, required, e.g. "Sandbox"
Return: $flag "1" if access may be granted, "0" if not
Since: TWiki::Plugins::VERSION 1.000 (27 Feb 2001)

Functions: Content Handling

webExists( $web ) ==> $flag

Description: Test if web exists
Parameter: $web Web name, required, e.g. "Sandbox"
Return: $flag "1" if web exists, "0" if not
Since: TWiki::Plugins::VERSION 1.000 (14 Jul 2001)

topicExists( $web, $topic ) ==> $flag

Description: Test if topic exists
Parameter: $web Web name, optional, e.g. "Main"
Parameter: $topic Topic name, required, e.g. "TokyoOffice", or "Main.TokyoOffice"
Return: $flag "1" if topic exists, "0" if not
Since: TWiki::Plugins::VERSION 1.000 (14 Jul 2001)

getRevisionInfo($theWebName, $theTopic, $theRev, $attachment ) ==> ( $date, $user, $rev, $comment )

Description: Get revision info of a topic
Parameter: $theWebName Web name, optional, e.g. "Main"
Parameter: $theTopic Topic name, required, e.g. "TokyoOffice"
Parameter: $theRev revsion number, or tag name (can be in the format 1.2, or just the minor number)
Parameter: $attachment attachment filename
Return: ( $date, $user, $rev, $comment ) List with: ( last update date, login name of last user, minor part of top revision number ), e.g. ( 1234561, "phoeny", "5" )
$date in epochSec
$user  
$rev  
$comment WHAT COMMENT?
Since: TWiki::Plugins::VERSION 1.000 (29 Jul 2001)

checkTopicEditLock( $web, $topic ) ==> ( $oopsUrl, $loginName, $unlockTime )

Description: Check if topic has an edit lock by a user
Parameter: $web Web name, e.g. "Main", or empty
Parameter: $topic Topic name, e.g. "MyTopic", or "Main.MyTopic"
Return: ( $oopsUrl, $loginName, $unlockTime ) The $oopsUrl for calling redirectCgiQuery(), user's $loginName, and estimated $unlockTime in minutes. The $oopsUrl and $loginName is empty if topic has no edit lock.
Since: TWiki::Plugins::VERSION 1.010 (31 Dec 2002)

setTopicEditLock( $web, $topic, $lock ) ==> $oopsUrl

Description: Lock topic for editing, or unlock when done
Parameter: $web Web name, e.g. "Main", or empty
Parameter: $topic Topic name, e.g. "MyTopic", or "Main.MyTopic"
Parameter: $lock Set to 1 to lock topic, 0 to unlock
Return: $oopsUrl Empty string if OK; the $oopsUrl for calling redirectCgiQuery() in case lock is already taken when trying to lock topic
Since: TWiki::Plugins::VERSION 1.010 (31 Dec 2002)

readTopicText( $web, $topic, $rev, $ignorePermissions ) ==> $text

Description: Read topic text, including meta data
Parameter: $web Web name, e.g. "Main", or empty
Parameter: $topic Topic name, e.g. "MyTopic", or "Main.MyTopic"
Parameter: $rev Topic revision to read, optional. Specify the minor part of the revision, e.g. "5", not "1.5"; the top revision is returned if omitted or empty.
Parameter: $ignorePermissions Set to "1" if checkAccessPermission() is already performed and OK; an oops URL is returned if user has no permission
Return: $text Topic text with embedded meta data; an oops URL for calling redirectCgiQuery() is returned in case of an error
Since: TWiki::Plugins::VERSION 1.010 (31 Dec 2002)

saveTopicText( $web, $topic, $text, $ignorePermissions, $dontNotify ) ==> $oopsUrl

Description: Save topic text, typically obtained by readTopicText(). Topic data usually includes meta data; the file attachment meta data is replaced by the meta data from the topic file if it exists.
Parameter: $web Web name, e.g. "Main", or empty
Parameter: $topic Topic name, e.g. "MyTopic", or "Main.MyTopic"
Parameter: $text Topic text to save, assumed to include meta data
Parameter: $ignorePermissions Set to "1" if checkAccessPermission() is already performed and OK
Parameter: $dontNotify Set to "1" if not to notify users of the change
Return: $oopsUrl Empty string if OK; the $oopsUrl for calling redirectCgiQuery() in case of error
Since: TWiki::Plugins::VERSION 1.010 (31 Dec 2002)

getPublicWebList( ) ==> @webs

Description: Get list of all public webs, e.g. all webs that do not have the NOSEARCHALL flag set in the WebPreferences
Return: @webs List of all public webs, e.g. ( "Main",  "Know", "TWiki" )
Since: TWiki::Plugins::VERSION 1.000 (7 Dec 2002)

getTopicList( $web ) ==> @topics

Description: Get list of all topics in a web
Parameter: $web Web name, required, e.g. "Sandbox"
Return: @topics Topic list, e.g. ( "WebChanges",  "WebHome", "WebIndex", "WebNotify" )
Since: TWiki::Plugins::VERSION 1.000 (7 Dec 2002)

Functions: Rendering

expandCommonVariables( $text, $topic, $web ) ==> $text

Description: Expand all common %VARIABLES%
Parameter: $text Text with variables to expand, e.g. "Current user is %WIKIUSER%"
Parameter: $topic Current topic name, e.g. "WebNotify"
Parameter: $web Web name, optional, e.g. "Main". The current web is taken if missing
Return: $text Expanded text, e.g. "Current user is TWikiGuest"
Since: TWiki::Plugins::VERSION 1.000 (7 Dec 2002)

renderText( $text, $web ) ==> $text

Description: Render text from TWiki markup into XHTML as defined in TWiki.TextFormattingRules
Parameter: $text Text to render, e.g. "*bold* text and =fixed font="
Parameter: $web Web name, optional, e.g. "Main". The current web is taken if missing
Return: $text XHTML text, e.g. "<b>bold</b> and <code>fixed font</code>"
Since: TWiki::Plugins::VERSION 1.000 (7 Dec 2002)

internalLink( $pre, $web, $topic, $label, $anchor, $createLink ) ==> $text

Description: Render topic name and link label into an XHTML link. Normally you do not need to call this funtion, it is called internally by renderText()
Parameter: $pre Text occuring before the TWiki link syntax, optional
Parameter: $web Web name, required, e.g. "Main"
Parameter: $topic Topic name to link to, required, e.g. "WebNotify"
Parameter: $label Link label, required. Usually the same as $topic, e.g. "notify"
Parameter: $anchor Anchor, optional, e.g. "#Jump"
Parameter: $createLink Set to "1" to add question linked mark after topic name if topic does not exist;
set to "0" to suppress link for non-existing topics
Return: $text XHTML anchor, e.g. "<a href="/cgi-bin/view/Main/WebNotify#Jump">notify</a>"
Since: TWiki::Plugins::VERSION 1.000 (7 Dec 2002)

search text( $text ) ==> $text

Description: This is not a function, just a how-to note. Use: expandCommonVariables("%SEARCH{...}%" );
Parameter: $text Search variable
Return: $text Search result in TWiki.FormattedSearch format

formatTime( $time, $format, $timezone ) ==> $text

Description: Format the time in seconds into the desired time string
Parameter: $time Time in epoc seconds
Parameter: $format Format type, optional. Default e.g. " TWiki::Plugins::VERSION 1.010 (31 Dec 2002) - 19:30", can be "iso" (e.g. "2002-12-31T19:30Z"), "rcs" (e.g. "2001/12/31 23:59:59", "http" for HTTP header format (e.g. "Thu, 23 Jul 1998 07:21:56 GMT")
Parameter: $timezone either not defined (uses the displaytime setting), "gmtime", or "servertime"
Return: $text Formatted time string
Note: if you used the removed formatGmTime, add a third parameter "gmtime"
Since: TWiki::Plugins::VERSION 1.020 (26 Feb 2004)

formatGmTime( $time, $format ) ==> $text

NOTE: The following function is deprecated and should not be used. Use formatTime() instead
Description: Format the time to GM time
Parameter: $time Time in epoc seconds
Parameter: $format Format type, optional. Default e.g. "31 Dec 2002 - 19:30", can be "iso" (e.g. "2002-12-31T19:30Z"), "rcs" (e.g. "2001/12/31 23:59:59", "http" for HTTP header format (e.g. "Thu, 23 Jul 1998 07:21:56 GMT")
Return: $text Formatted time string
Since: TWiki::Plugins::VERSION 1.000 (7 Dec 2002)

Functions: File I/O

getDataDir( ) ==> $dir

Description: Get data directory (topic file root)
Return: $dir Data directory, e.g. "/twiki/data"
Since: TWiki::Plugins::VERSION 1.000 (7 Dec 2002)

getPubDir( ) ==> $dir

Description: Get pub directory (file attachment root). Attachments are in $dir/Web/TopicName
Return: $dir Pub directory, e.g. "/htdocs/twiki/pub"
Since: TWiki::Plugins::VERSION 1.000 (7 Dec 2002)

readTopic( $web, $topic ) ==> ( $meta, $text )

NOTE: The following function is deprecated and should not be used. Use readTopicText() instead
Description: Read topic text and meta data, regardless of access permissions.
Parameter: $web Web name, required, e.g. "Main"
Parameter: $topic Topic name, required, e.g. "TokyoOffice"
Return: ( $meta, $text ) Meta data object and topic text
Since: TWiki::Plugins::VERSION 1.000 (7 Dec 2002)

readTemplate( $name, $skin ) ==> $text

Description: Read a template or skin file. Embedded template directives get expanded
Parameter: $name Template name, e.g. "view"
Parameter: $skin Skin name, optional, e.g. "print"
Return: $text Template text
Since: TWiki::Plugins::VERSION 1.000 (7 Dec 2002)

readFile( $filename ) ==> $text

Description: Read text file, low level. NOTE: For topics use readTopicText()
Parameter: $filename Full path name of file
Return: $text Content of file
Since: TWiki::Plugins::VERSION 1.000 (7 Dec 2002)

saveFile( $filename, $text )

Description: Save text file, low level. NOTE: For topics use saveTopicText()
Parameter: $filename Full path name of file
Parameter: $text Text to save
Return: none
Since: TWiki::Plugins::VERSION 1.000 (7 Dec 2002)
TODO: This should return an error for the different failure modes.

writeWarning( $text )

Description: Log Warning that may require admin intervention to data/warning.txt
Parameter: $text Text to write; timestamp gets added
Return: none
Since: TWiki::Plugins::VERSION 1.020 (16 Feb 2004)

writeDebug( $text )

Description: Log debug message to data/debug.txt
Parameter: $text Text to write; timestamp gets added
Return: none
Since: TWiki::Plugins::VERSION 1.020 (16 Feb 2004)

Functions: I18N related

getRegularExpression( $regexName ) ==> $pattern

Description: Retrieves a TWiki predefined regular expression
Parameter: $regexName Name of the regular expression to retrieve. See notes below
Return: String or precompiled regular expression matching as described below
Since: TWiki::Plugins::VERSION 1.020 (9 Feb 2004)

Notes: TWiki internally precompiles several regular expressions to represent various string entities in an I18N-compatible manner. Plugins are encouraged to use these in matching where appropriate. The following are guaranteed to be present; others may exist, but their use is unsupported and they may be removed in future TWiki versions. Those which are marked "CC" are for use within character classes and may not produce the desired results outside of them.

Name down Matches CC
lowerAlpha Lower case characters Y
mixedAlpha Alphabetic characters Y
mixedAlphaNum Alphanumeric charactecs Y
upperAlpha Upper case characters Y
wikiWordRegex WikiWords N

Example:

   my $upper = TWiki::Func::getRegularExpression("upperAlpha");
   my $alpha = TWiki::Func::getRegularExpression("mixedAlpha");
   my $capitalized = qr/[$upper][$alpha]+/;

setTopicRevisionTag( $web, $topic, $rev, $tag ) ==> $success

Description: sets a names tag on the specified revision
Parameter: $web webname
Parameter: $topic topic name
Parameter: $rev the revision we are taging
Parameter: $tag the string to tag with
Return: $success  
TODO: we need an error mechanism!
Since: TWiki::Plugins::VERSION 1.022 (20 April 2004)

checkDependencies

Description: checks a list of Perl dependencies at runtime
Parameter: $context Context description e.g. name of the module being checked
Parameter: $deps List of hashes containing dependency information
Returns: undef if dependencies are OK, an error message otherwise
Since: TWiki::Plugins::VERSION 1.025 (01 Aug 2004)

The dependencies are expressed as a list of hashes. Each hash contains the name of a package and (optionally) a boolean constraint on the VERSION variable in that package. It is usually used from the initPlugin method like this:

   if( $TWiki::Plugins::VERSION >= 1.025 ) {
      my @deps = (
            { package => 'TWiki::Plugins::CalendarPlugin', constraint => '>= 5.030' },
            { package => 'Time::ParseDate' },
            { package => 'Apache::VMonitor' }
      );
      my $err = TWiki::Func::checkDependencies( $pluginName, \@deps );
      if( $err ) {
            TWiki::Func::writeWarning( $err );
            print STDERR $err; # print to webserver log file
            return 0; # plugin initialisation failed
      }
   }

Copyright and License

Copyright (C) 2000-2004 Peter Thoeny, Peter@Thoeny.com

This program is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 2 of the License, or (at your option) any later version.

This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details, published at http://www.gnu.org/copyleft/gpl.html

NOTE: Above text is copied from the TWiki::Plugins/PerlDocPlugin output of TWiki::Func in twiki format. In case you want to get dynamically updated documentation based on the actual Perl module, install the PerlDocPlugin and replace above text with %PERLDOC{"TWiki::Func"}%.

-- PeterThoeny - 31 Dec 2002