ForEachPlugin

This plugin provides basic FOR and FOREACH loop constructions.

Syntax Rules

• All parameters are required, and must appear in the specified order.

FOREACH Examples

Basic Usage

%FOREACH{"web" in="Main, Sandbox, TWiki"}%
   * [[$web.WebHome]]
%NEXT{"web"}%

... gives ...

• Main.WebHome
• Sandbox.WebHome
• TWiki.WebHome

... if installed.

• Main.WebHome
• Sandbox.WebHome
• TWiki.WebHome

Nested loops are possible:

%FOREACH{"i" in="1, 2, 3"}% %FOREACH{"j" in="a, b, c"}% $i$j %NEXT{"j"}% %NEXT{"i"}%

Lists may contain TWiki Variables or other plugins.

• The body of the loop may need to delay expansion: use $percnt to replace % if necessary.

%FOREACH{"web" in="%WEBLIST{"$name" separator=", "}%"}%
| $web | $percntFORMFIELD{"STATUS" topic="$web.%HOMETOPIC%" default="Formfield STATUS not defined in $web" alttext="Formfield STATUS not found in $web"}$percnt |
%NEXT{"web"}%

FOR Examples

Count up and down in steps

• %FOR{"counta" start="1" stop="10" step="2"}% $counta %NEXT{"counta"}%
• 1 3 5 7 9
• %FOR{"countb" start="1" stop="10" step="1"}% $countb %NEXT{"countb"}%
• 1 2 3 4 5 6 7 8 9 10
• %FOR{"countc" start="10" stop="1" step="-1"}% $countc %NEXT{"countc"}%
• 10 9 8 7 6 5 4 3 2 1

Nested loops are possible:

%FOR{"outer" start="1" stop="3" step="1"}%
%FOR{"inner" start="3" stop="1" step="-1"}%
   * $outer - $inner 
%NEXT{"inner"}%
%NEXT{"outer"}%

• 1 - 103
• 1 - 102
• 1 - 101
• 1 - 100
• 2 - 103
• 2 - 102
• 2 - 101
• 2 - 100
• 3 - 103
• 3 - 102
• 3 - 101
• 3 - 100

Error trapping

• %FOR{"countd" start="10" stop="1" step="1"}% $countd %NEXT{"countd"}% (invalid step)
• FOR countd : Bad step
• %FOR{"counte" start="a" stop="b" step="c"}% $countd %NEXT{"counte"}% (non-integers)
• FOR{"counte" start="a" stop="b" step="c"} : Not a number

Plugin Settings

Plugin settings are stored as preferences variables. To reference a plugin setting write %<plugin>_<setting>%, i.e. %INTERWIKIPLUGIN_SHORTDESCRIPTION%

• One line description, is shown in the TextFormattingRules topic:
  • Set SHORTDESCRIPTION = Loop over successive elements of a list, or a range of numbers.

• Debug plugin: (See output in data/debug.txt)
  • Set DEBUG = 0

Plugin Installation Instructions

Note: You do not need to install anything on the browser to use this plugin. The following instructions are for the administrator who installs the plugin on the server where TWiki is running.

• Download the ZIP file from the Plugin web (see below)
• Unzip ForEachPlugin.zip in your twiki installation directory. Content:

  File:	Description:
  data/TWiki/ForEachPlugin.txt	Plugin topic
  data/TWiki/ForEachPlugin.txt,v	Plugin topic repository
  lib/TWiki/Plugins/ForEachPlugin.pm	Plugin Perl module

• Test if the installation was successful:
  • enter samples here

Plugin Info

Related Topics: TWikiPreferences, TWikiPlugins

-- TWiki:Main.MagnusLewisSmith - 28 Sep 2005