TWiki Variables

Special text strings expand on the fly to display user data or system info

TWikiVariables are text strings - %VARIABLE% or %VARIABLE{ parameter="value" }% - that expand into content whenever a topic is rendered for viewing. There are two types of variables:

  1. Preferences variables: Can be defined and changed by the user
  2. Predefined variables: Defined by the TWiki system or by Plugins (for example, the SpreadSheetPlugin? introduces a %CALC{}% variable)

Using Variables

To use a variable type its name. For example,

  • type %T% to get TIP (a preferences variable)
  • type %TOPIC% to get TWikiVariables (a predefined variable)
  • type %CALC{ "$UPPER(Text)" }% to get TEXT (a variable defined by Plugin)

Note:

  • To leave a variable unexpanded, precede it with an exclamation point, e.g. type !%TOPIC% to get %TOPIC%
  • Variables are expanded relative to the topic they are used in, not the topic they are defined in
  • Type %ALLVARIABLES% to get a full listing of all variables defined for a particular topic

Preferences Variables

Unlike predefined variables, preferences variables can be defined by the user in various places.

Setting Preferences Variables

You can set variables in all the following places:
  1. local site level in SitePreferences
  2. user level in individual user topics in Main web
  3. web level in WebPreferences of each web
  4. topic level in topics in webs
  5. plugin topics (see TWikiPlugins)
  6. session variables (if sessions are enabled)

Settings at higher-numbered levels override settings of the same variable at lower numbered levels, unless the variable was included in the setting of FINALPREFERENCES at a lower-numbered level, in which case it is locked at the value it has at that level.

The syntax for setting Variables is the same anywhere in TWiki (on its own TWiki bullet line, including nested bullets):
[multiple of 3 spaces] * [space] Set [space] VARIABLENAME [space] = [space] value

Examples:
  • Set VARIABLENAME = value
    • Set VARIABLENAME = value
Spaces between the = sign and the value will be ignored. You can split a value over several lines by indenting following lines with spaces - as long as you don't try to use * as the first character on the following line.
Example:
   * Set VARIABLENAME = value starts here
     and continues here

Whatever you include in your Variable will be expanded on display, exactly as if it had been entered directly.

Example: Create a custom logo variable
  • To place a logo anywhere in a web by typing %MYLOGO%, define the Variable on the web's WebPreferences topic, and upload a logo file, ex: mylogo.gif. You can upload by attaching the file to WebPreferences, or, to avoid clutter, to any other topic in the same web, e.g. LogoTopic. Sample variable setting in WebPreferences:
    • Set MYLOGO = %PUBURL%/%WEB%/LogoTopic/mylogo.gif

You can also set preferences variables on a topic by clicking the link Edit topic preference settings under More topic actions. Preferences set in this manner are not visible in the topic text, but take effect nevertheless.

Access Control Variables

These are special types of preferences variables to control access to content. TWikiAccessControl explains these security settings in detail.

Local values for variables

Certain topics (a users home topic, web site and default preferences topics) have a problem; variables defined in those topics can have two meanings. For example, consider a user topic. A user may want to use a double-height edit box when they are editing their home topic - but only when editing their home topic. The rest of the time, they want to have a normal edit box. This separation is achieved using Local in place of Set in the variable definition. For example, if the user sets the following in their home topic:
   * Set EDITBOXHEIGHT = 10
   * Local EDITBOXHEIGHT = 20
Then when they are editing any other topic, they will get a 10 high edit box. However when they are editing their home topic, they will get a 20 high edit box. Local can be used wherever a preference needs to take a different value depending on where the current operation is being performed.

Use this powerful feature with great care! %ALLVARIABLES% can be used to get a listing of the values of all variables in their evaluation order, so you can see variable scope if you get confused.

Frequently Used Preferences Variables

The following preferences variables are frequently used. They are defined in TWikiPreferences#Miscellaneous_Settings:

  • %BR% - line break
  • %BULLET% - bullet sign
  • %BB% - line break and bullet combined
  • %BB2% - indented line break and bullet
  • %RED% text %ENDCOLOR% - colored text (also %YELLOW%, %ORANGE%, %PINK%, %PURPLE%, %TEAL%, %NAVY%, %BLUE%, %AQUA%, %LIME%, %GREEN%, %OLIVE%, %MAROON%, %BROWN%, %BLACK%, %GRAY%, %SILVER%, %WHITE%)
  • %H% - HELP Help icon
  • %I% - IDEA! Idea icon
  • %M% - MOVED TO... Moved to icon
  • %N% - NEW New icon
  • %P% - REFACTOR Refactor icon
  • %Q% - QUESTION? Question icon
  • %S% - PICK Pick icon
  • %T% - TIP Tip icon
  • %U% - UPDATED Updated icon
  • %X% - ALERT! Alert icon
  • %Y% - DONE Done icon

There are additional useful preferences variables defined in TWikiPreferences, in Main.SitePreferences, and in WebPreferences of every web.

Predefined Variables

Most predefined variables return values that were either set in the configuration when TWiki was installed, or taken from server info (such as current username, or date and time). Some, like %SEARCH%, are powerful and general tools.

  • ALERT! Predefined variables can be overridden by preferences variables
  • ALERT! Plugins may extend the set of predefined variables (see individual Plugins topics for details)
  • TIP Take the time to thoroughly read through ALL preference variables. If you actively configure your site, review variables periodically. They cover a wide range of functions, and it can be easy to miss the one perfect variable for something you have in mind. For example, see %INCLUDINGTOPIC%, %INCLUDE%, and the mighty %SEARCH%.

This version of TWiki - Foswiki-1.0.10, Wed, 08 Sep 2010, build 8969 - predefines the following variables:

ACTIVATEDPLUGINS -- list of currently activated plugins

ALLVARIABLES -- list of currently defined TWikiVariables

  • Syntax: %ALLVARIABLES%
  • Expands to: a table showing all defined TWikiVariables in the current context

ATTACHURL -- full URL for attachments in the current topic

ATTACHURLPATH -- path of the attachment URL of the current topic

AUTHREALM -- authentication realm

  • String defined as {AuthRealm} in configure. This is used in certain password encodings, and in login templates as part of the login prompt.
  • Syntax: %AUTHREALM%
  • Expands to: Enter your WikiName. (First name and last name, no space, no dots, capitalized, e.g. JohnSmith?). Cancel to register if you do not have one.
  • Related: TWikiUserAuthentication, SESSIONID, SESSIONVAR, LOGIN, LOGOUT, SESSION_VARIABLE

BASETOPIC -- base topic where an INCLUDE started

  • The name of the topic where a single or nested INCLUDE started - same as %TOPIC% if there is no INCLUDE
  • Syntax: %BASETOPIC%
  • Related: BASEWEB, INCLUDINGTOPIC, INCLUDE, TOPIC

BASEWEB -- base web where an INCLUDE started

  • The web name where the includes started, e.g. the web of the first topic of nested includes. Same as %WEB% in case there is no include.
  • Syntax: %BASEWEB%
  • Related: BASETOPIC, INCLUDINGWEB, INCLUDE, WEB

DATE -- signature format date

DISPLAYTIME -- display time

DISPLAYTIME{"format"} -- formatted display time

  • Formatted time - either GMT or Local server time, depending on setting in configure. Same format qualifiers as %GMTIME%
  • Syntax: %DISPLAYTIME{"format"}%
  • Example: %DISPLAYTIME{"$hou:$min"}% expands to 20:06
  • Related: DISPLAYTIME, GMTIME, SERVERTIME

ENCODE{"string"} -- encodes a string to HTML entities

Encode "special" characters to HTML numeric entities. Encoded characters are:
  • all non-printable ascii chars (< \x1f), except \n (\xa) and \r (\xd)
  • HTML special characters '>', '<', '&', ''' and '"'.
  • TWiki special characters '%', '[', ']', '@', '_', '*' and '='
  • Syntax: %ENCODE{"string"}%
  • Supported parameters:
    Parameter: Description: Default:
    "string" String to encode required (can be empty)
    type="entity" Encode special characters into HTML entities, like a double quote into &#034; URL encoding
    type="url" Encode special characters for URL parameter use, like a double quote into %22 (this is the default)
  • Example: %ENCODE{"spaced name"}% expands to spaced%20name
  • Related: URLPARAM

ENDSECTION{"name"} -- marks the end of a named section

FAILEDPLUGINS -- debugging for plugins that failed to load, and handler list

FORMFIELD{"format"} -- renders a field in the form attached to some topic

  • Syntax: %FORMFIELD{"fieldname"}%
  • Supported parameters:
    Parameter: Description: Default:
    "fieldname" The name of a TWiki form field required
    topic="..." Topic where form data is located. May be of the form Web.TopicName Current topic
    format="..." Format string. $value expands to the field value, and $title expands to the field title "$value"
    default="..." Text shown when no value is defined for the field ""
    alttext="..." Text shown when field is not found in the form ""
  • Example: %FORMFIELD{"ProjectName" topic="Projects.SushiProject" default="(not set)" alttext="ProjectName field found"}%
  • Related: SEARCH

GMTIME -- GM time

GMTIME{"format"} -- formatted GM time

  • Syntax: %GMTIME{"format"}%
  • Supported variables:
    Variable: Unit: Example
    $seconds seconds 59
    $minutes minutes 59
    $hours hours 23
    $day day of month 31
    $wday day of the Week (Sun, Mon, Tue, Wed, Thu, Fri, Sat) Thu
    $dow day of the week (Sun = 0) 2
    $week number of week in year (ISO 8601) 34
    $month month in ISO format Dec
    $mo 2 digit month 12
    $year 4 digit year 1999
    $ye 2 digit year 99
    $tz either "GMT" (if set to gmtime), or "Local" (if set to servertime) GMT
    $iso ISO format timestamp 2017-10-20T20:06:33Z
    $rcs RCS format timestamp 2017/10/20 20:06:33
    $http E-mail & http format timestamp Fri, 20 Oct 2017 20:06:33 GMT
    $epoch Number of seconds since 00:00 on 1st January, 1970 1508529993
  • Variables can be shortened to 3 characters
  • Example: %GMTIME{"$day $month, $year - $hour:$min:$sec"}% expands to 20 Oct, 2017 - 20:06:33
  • ALERT! Note: When used in a template topic, this variable will be expanded when the template is used to create a new topic. See TWikiTemplates#TemplateTopicsVars for details.
  • Related: DISPLAYTIME, GMTIME, SERVERTIME

HOMETOPIC -- home topic in each web

HTTP -- get HTTP headers

HTTPS -- get HTTPS headers

  • The same as %HTTP% but operates on the HTTPS environment variables present when the SSL protocol is in effect. Can be used to determine whether SSL is turned on.
  • Syntax: %HTTPS%
  • Syntax: %HTTPS{'Header-name'}%
  • Related: HTTP, REMOTE_ADDR, REMOTE_PORT, REMOTE_USER

HTTP_HOST -- environment variable

ICON{"name"} -- small documentation graphic or icon of common attachment types

  • Small graphic images stored in TWikiDocGraphics, used to enhance topics. Also a collection of common file type icons. Specify file type only, file name, or full path name of file. Graphics typically have 16x16 pixels.
  • Syntax: %ICON{"name"}%
  • Graphic samples: arrowbright arrowbright, bubble bubble, choice-yes choice-yes, hand hand
  • File type samples: bmp bmp, doc doc, gif gif, hlp hlp, html html, mp3 mp3, pdf pdf, ppt ppt, txt txt, xls xls, xml xml, zip zip
  • Example: %ICON{"info"}% expands to HTML img tag info
  • Related: ICONURL, ICONURLPATH, DefaultPreferences?, FileAttachments, TWikiDocGraphics

ICONURL{"name"} -- URL of small documentation graphic or icon

  • Generates the URL of an image, typically used in an HTML img tag (contrast with %ICON{"name"}%, which generates the full img tag)
  • Syntax: %ICONURL{"name"}%
  • Example: %ICONURL{"info"}% expands to URL http://wiki.softwarelivre.org/pub/System/DocumentGraphics/info.gif, which renders as info.gif
  • Related: ICONURLPATH, ICON, DefaultPreferences?, FileAttachments, TWikiDocGraphics

ICONURLPATH{"name"} -- URL path of small documentation graphic or icon

  • Generates the URL path of an image, typically used in an HTML img tag
  • Syntax: %ICONURLPATH{"name"}%
  • Example: %ICONURLPATH{"info"}% expands to /pub/System/DocumentGraphics/info.gif
  • Related: ICONURL, ICON, DefaultPreferences?, FileAttachments, TWikiDocGraphics

IF{"condition" ...} -- simple conditionals

  • Evaluate a condition and show one text or another based on the result. See details in IfStatements
  • Syntax: %IF{"CONDITION" then="THEN" else="ELSE"}% shows "THEN" if "CONDITION" evaluates to TRUE, otherwise "ELSE" will be shown
  • Example: %IF{"defined FUNFACTOR" then="FUNFACTOR is defined" else=" is not defined"}% renders as ==
  • Related: $IF()? of SpreadSheetPlugin?

INCLUDE{"page"} -- include other topic or web page

  • Syntax: %INCLUDE{"page" ...}%
  • Supported parameters:
    Parameter: Description: Default:
    "SomeTopic" The name of a topic located in the current web, i.e. %INCLUDE{"WebNotify"}%  
    "Web.Topic" A topic in another web, i.e. %INCLUDE{"TWiki.SiteMap"}%  
    "http://..." A full qualified URL, i.e. %INCLUDE{"http://twiki.org:80/index.html"}%. Supported content types are text/html and text/plain.
    IDEA! if the URL resolves to an attachment file on the server this will automatically translate to a server-side include.
     
    pattern="..." A RegularExpression pattern to include a subset of a topic or page none
    rev="2" Include a previous topic revision; N/A for URLs top revision
    warn="off" Warn if topic include fails: Fail silently (if off); output default warning (if set to on); else, output specific text (use $topic for topic name) %INCLUDEWARNING% preferences setting
    section="name" Includes only the specified section, as defined in the included topic by the SECTION and ENDSECTION variables  
    PARONE="val 1"
      PARTWO="val 2"
    Any other parameter will be defined as a variable within the scope of the included topic. The example parameters on the left will result in %PARONE% and %PARTWO% being defined within the included topic.  
  • Examples: See IncludeTopicsAndWebPages
  • Related: BASETOPIC, BASEWEB, INCLUDINGTOPIC, INCLUDINGWEB, STARTINCLUDE, STOPINCLUDE, SECTION, ENDSECTION

INCLUDINGTOPIC -- name of topic that includes current topic

  • The name of the topic that includes the current topic - same as %TOPIC% in case there is no include
  • Syntax: %INCLUDINGTOPIC%
  • Related: BASETOPIC, INCLUDINGWEB, INCLUDE, TOPIC

INCLUDINGWEB -- web that includes current topic

  • The web name of the topic that includes the current topic - same as %WEB% if there is no INCLUDE.
  • Syntax: %INCLUDINGWEB%
  • Related: BASEWEB, INCLUDINGTOPIC, INCLUDE, WEB

LANGUAGES -- list available TWiki languages

  • List the languages available (as PO files) to TWiki. Those are the languages in which TWiki's user interface is available.
  • Syntax: %LANGUAGES{...}%
  • Supported parameters:
    Parameter: Description: Default:
    format format for each item. See below for variables available in the format string. "   * $langname"
    separator separator between items. "\n" (newline)
  • format variables:
    Variable Meaning
    $langname language's name, as informed by the translators
    $langtag language's tag. Ex: en, pt-br, etc.

LOCALSITEPREFS -- web.topicname of site preferences topic

  • The full name of the local site preferences topic. This topic is read for preferences before TWiki.%TWIKIPREFSTOPIC% is read.
  • Syntax: %LOCALSITEPREFS%
  • Expands to: Main.SitePreferences, renders as SitePreferences

LOGIN -- present a full login link

LOGOUT -- present a full logout link

MAKETEXT -- creates text using TWiki's I18N? infrastructure

  • Syntax: %MAKETEXT{"string" args="..."}
  • Supported parameters:
    Parameter Description Default
    "text" or string="text" The text to be displayed. none
    args="param1, param2" a comma-separated list of arguments to be interpolated in the string, replacing the [_N] placeholders in it. none
  • Examples:
    • %MAKETEXT{string="Notes:"}%
      expands to
      Notes:
    • %MAKETEXT{"Contact [_1] if you have any questions." args="%WIKIWEBMASTER%"}%
      expands to
      Contact wikiwebmaster@softwarelivre.org if you have any questions.
    • %MAKETEXT{"Did you want to [[[_1]][reset [_2]'s password]]?" args="TWiki.ResetPassword,%WIKIUSERNAME%"}%
      expands to
      Did you want to reset Main.WikiGuest's password??
  • Notes:
    • TWiki will translate the string to the current user's language only if it has such string in its translation table for that language.
    • Amperstands (&) followed by one letter (one of a...z, A...Z) (say, X) in the translatable string will be translated to <span class='twikiAccessKey'>X</span>. This is used to implement access keys. If you want to write an actual amperstand that stays just before a letter, write two consecutive amperstands (&&): they will be transformed in just one.
    • translatable string starting with underscores (_) are reserved. You should not use translatable phrases starting with an underscore.
    • Make sure that the translatable string is constant. Specially, do not include %VARIABLES% inside the translatable strings (since they will get expanded before the %MAKETEXT{...}% itself is handled).

MAINWEB -- name of Main web

  • The web containing WikiUsers, individual user topics and TWikiGroups?
  • Syntax: %MAINWEB%
  • Expands to: Main
  • Related: TWIKIWEB

META -- displays meta-data

  • Provided mainly for use in templates, this variable generates the parts of the topic view that relate to meta-data (attachments, forms etc.) The formfield item is the most likely to be useful to casual users.
  • Syntax: %META{ "item" ...}%
  • Parameters:
    Item Options Description
    "formfield" name="..." - name of the field. The field value can be shortened as described in FormattedSearch? for $formfield Show a single form field
    "form" none Generates the table showing the form fields. See Form Templates
    "attachments" all="on" to show hidden attachments Generates the table showing the attachments
    "moved" none Details of any topic moves
    "parent" dontrecurse="on": By default recurses up tree, this has some cost.
    nowebhome="on": Suppress WebHome.
    prefix="...": Prefix that goes before parents, but only if there are parents, default "".
    suffix="...": Suffix, only appears if there are parents, default "".
    separator="...": Separator between parents, default is " > ".
    Generates the parent link
  • Related: METASEARCH

METASEARCH -- special search of meta data

  • Syntax: %METASEARCH{...}%
  • Supported parameters:
    Parameter: Description: Default:
    type="topicmoved" What sort of search is required?
    "topicmoved" if search for a topic that may have been moved
    "parent" if searching for topics that have a specific parent i.e. its children
    "field" if searching for topics that have a particular form field value (use the name and value parameters to specify which field to search)
    required
    web="%WEB%" Wiki web to search: A web, a list of webs separated by whitespace, or all webs. current web
    topic="%TOPIC%" The topic the search relates to, for topicmoved and parent searches current topic
    name form field to search, for field type searches. May be a regular expression (see SEARCH).  
    value form field value, for field type searches. May be a regular expression (see SEARCH).  
    title="Title" Text that is prefixed to any search results empty
    default="none" Default text shown if no search hit empty
  • Example: %METASEARCH{type="topicmoved" web="%WEB%" topic="%TOPIC%" title="This topic used to exist and was moved to: "}%
  • Example: You may want to use this in WebTopicViewTemplate and WebTopicNonWikiTemplate:
    %METASEARCH{type="parent" web="%WEB%" topic="%TOPIC%" title="Children: "}%
  • Example: %METASEARCH{type="field" name="Country" value="China"}%
  • Related: SEARCH, META

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Related Topics: UserDocumentationCategory

Topic revision: r0 - 27 Mar 2005 - 13:14:15 - TWikiContributor
 
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