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r82 - 19 Mar 2006 - 20:23:10 - TWikiContributorYou are here: Baanboard.com Wiki >  TWiki Web > TWikiVariables

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

Variable Names

Variable names must start with a letter. The following characters can be letters, numbers and the underscore '_'. You can use both upper-case and lower-case letters and you can mix the characteres. E.g. %MYVAR%, %MyVar%, %My2ndVar%, and %My_Var% are all valid variable names. Variables are case sensitive. %MyVAR% and %MYVAR% are not the same variable.

By convention all settings, predefined variables and variables used by plugins are always UPPER-CASE.

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 TWiki.TWikiPreferences
  2. plugin topics (see TWikiPlugins)
  3. local site level in Main.TWikiPreferences
  4. user level in individual user topics in Main web
  5. web level in WebPreferences of each web
  6. topic level in topics in webs
  7. 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.TWikiPreferences, 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 - TWiki-4.1.1, Mon, 05 Feb 2007, build 12770 - 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

AQUA -- start aqua colored text

  • AQUA is one of the rendering shortcut settings predefined in TWikiPreferences. See the section rendering shortcut settings in that topic for a complete list of colors.
  • Syntax: %AQUA% aqua text %ENDCOLOR%
  • Expands to: aqua text
  • Note: %<color>% text must end with %ENDCOLOR%. If you want to switch from one color to another one you first need to end the active color with %ENDCOLOR%, e.g. write %RED% some text %ENDCOLOR% %GREEN% more text %ENDCOLOR%.
  • Related: ENDCOLOR, TWikiPreferences, StandardColors

ATTACHURL -- full URL for attachments in the current topic

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

AUTHREALM -- authentication realm

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

BB -- bullet with line break

BB2 -- level 2 bullet with line break

BB3 -- level 3 bullet with line break

BB4 -- level 4 bullet with line break

BLACK -- start black colored text

  • BLACK is one of the rendering shortcut settings predefined in TWikiPreferences. See the section rendering shortcut settings in that topic for a complete list of colors.
  • Syntax: %BLACK% black text %ENDCOLOR%
  • Expands to: black text
  • Note: %<color>% text must end with %ENDCOLOR%. If you want to switch from one color to another one you first need to end the active color with %ENDCOLOR%, e.g. write %RED% some text %ENDCOLOR% %GREEN% more text %ENDCOLOR%.
  • Related: ENDCOLOR, TWikiPreferences, StandardColors

BLUE -- start blue colored text

  • BLUE is one of the rendering shortcut settings predefined in TWikiPreferences. See the section rendering shortcut settings in that topic for a complete list of colors.
  • Syntax: %BLUE% blue text %ENDCOLOR%
  • Expands to: blue text
  • Note: %<color>% text must end with %ENDCOLOR%. If you want to switch from one color to another one you first need to end the active color with %ENDCOLOR%, e.g. write %RED% some text %ENDCOLOR% %GREEN% more text %ENDCOLOR%.
  • Related: ENDCOLOR, TWikiPreferences, StandardColors

BR -- line break

BROWN -- start brown colored text

  • BROWN is one of the rendering shortcut settings predefined in TWikiPreferences. See the section rendering shortcut settings in that topic for a complete list of colors.
  • Syntax: %BROWN% brown text %ENDCOLOR%
  • Expands to: brown text
  • Note: %<color>% text must end with %ENDCOLOR%. If you want to switch from one color to another one you first need to end the active color with %ENDCOLOR%, e.g. write %RED% some text %ENDCOLOR% %GREEN% more text %ENDCOLOR%.
  • Related: ENDCOLOR, TWikiPreferences, StandardColors

BULLET -- bullet character

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 02:34
  • 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 characters below space, except newline ("\n") and linefeed ("\r")
    • HTML special characters "<", ">", "&", single quote (') and double quote (")
    • 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;. Does not encode \n or \r. type="url"
    type="html" As type="entity" except it also encodes \n and \r type="url"
    type="quote" Escape double quotes with backslashes (\"), does not change other characters type="url"
    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
  • ALERT! Note: Values of HTML input fields must be entity encoded.
    Example: <input type="text" name="address" value="%ENCODE{ "any text" type="entity" }%" />
  • ALERT! Note: Double quotes in strings must be escaped when passed into other TWiki variables.
    Example: %SEARCH{ "%ENCODE{ "string with "quotes"" type="quotes" }%" noheader="on" }%

ENDCOLOR -- end colored text

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

  • Syntax: %ENDSECTION{"name"}%
  • Syntax: %ENDSECTION{type="include"}%
  • Supported parameter:
    Parameter: Description:
    "name" Name of the section.
    type="..." Type of the section being terminated; supported types "section", "include", "templateonly".
  • If the STARTSECTION is named, the corresponding ENDSECTION must also be named with the same name. If the STARTSECTION specifies a type, then the corresponding ENDSECTION must also specify the same type. If the section is unnamed, ENDSECTION will match with the nearest unnamed %STARTSECTION% of the same type above it.
  • Related: STARTSECTION

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

FORMFIELD{"fieldname"} -- 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 2008-05-14T02:34:40Z
    $rcs RCS format timestamp 2008/05/14 02:34:40
    $http E-mail & http format timestamp Wed, 14 May 2008 02:34:40 GMT
    $epoch Number of seconds since 00:00 on 1st January, 1970 1210732480
  • Variables can be shortened to 3 characters
  • Example: %GMTIME{"$day $month, $year - $hour:$min:$sec"}% expands to 14 May, 2008 - 02:34:40
  • 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, REVINFO, SERVERTIME

GRAY -- start gray colored text

  • GRAY is one of the rendering shortcut settings predefined in TWikiPreferences. See the section rendering shortcut settings in that topic for a complete list of colors.
  • Syntax: %GRAY% gray text %ENDCOLOR%
  • Expands to: gray text
  • Note: %<color>% text must end with %ENDCOLOR%. If you want to switch from one color to another one you first need to end the active color with %ENDCOLOR%, e.g. write %RED% some text %ENDCOLOR% %GREEN% more text %ENDCOLOR%.
  • Related: ENDCOLOR, TWikiPreferences, StandardColors

GREEN -- start green colored text

  • GREEN is one of the rendering shortcut settings predefined in TWikiPreferences. See the section rendering shortcut settings in that topic for a complete list of colors.
  • Syntax: %GREEN% green text %ENDCOLOR%
  • Expands to: green text
  • Note: %<color>% text must end with %ENDCOLOR%. If you want to switch from one color to another one you first need to end the active color with %ENDCOLOR%, e.g. write %RED% some text %ENDCOLOR% %GREEN% more text %ENDCOLOR%.
  • Related: ENDCOLOR, TWikiPreferences, StandardColors

GROUPS -- a formatted list of groups

H -- help icon

HOMETOPIC -- home topic in each web

HTTP -- get HTTP headers

  • Called with the name of an HTTP header field, returns its value. Capitalization and the use of hyphens versus underscores are not significant.
  • Syntax: %HTTP%
  • Syntax: %HTTP{"Header-name"}%
  • Examples:
    %HTTP%  
    %HTTP{"Accept-language"}% en-us,en;q=0.5
    %HTTP{"User-Agent"}% CCBot/1.0 (+http://www.commoncrawl.org/bot.html)
  • ALERT! Note: You can see the HTTP headers your browser sends to the server on a number of sites e.g. http://www.ericgiguere.com/tools/http-header-viewer.html
  • Related: HTTPS, REMOTE_ADDR, REMOTE_PORT, REMOTE_USER

HTTP_HOST -- environment variable

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: