This plugin provides basic FOR and FOREACH loop constructions.

ALERT! This plugin provides some macros which do not follow normal macro expansion rules and may behave strangely under some more advanced usage scenarios (such as when CALC is involved). Please consider replacing your usage of ForEachPlugin with one of the alternatives described in Foswiki:Support.Faq39

Syntax Rules

Tag Description
%FOREACH{"_var_" in="_list_"}% body %NEXT{"_var_"}% Loop over _body_ setting control variable _var_ to each successive element of _list_
%FOR{"_var_" start="_int_" stop="_int_" step="_int_"}% body %NEXT{"_var_"}% Loop over _body_ setting control variable _var_ to each integer in the range start to stop in steps of step

Parameters Description
"..." Loop control variable. Within the body of the text this may be referred to as $var. %FOREACH{"var" ...}% must have a matching %NEXT{"var"}%
in="..." Comma separated list. May contain Foswiki macros
"..." Loop control variable. Within the body of the text this may be referred to as $var. %FOR{"var" ...}% must have a matching %NEXT{"var"}%
"start"="..." Starting integer
"stop"="..." Stop integer
"step"="..." Increment/decrement var in steps of step. THIS IS REQUIRED

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

FOREACH Examples

Basic Usage

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

... gives ...

... if installed.

Nested loops are possible:

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

Lists may contain Foswiki macros 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 |
DaqSlowControl Formfield STATUS not found in DaqSlowControl
HODO Formfield STATUS not found in HODO
Homepages Formfield STATUS not found in Homepages
InterWikis Formfield STATUS not found in InterWikis
Main Formfield STATUS not found in Main
PionBeam Formfield STATUS not found in PionBeam
Sandbox Formfield STATUS not found in Sandbox
System Formfield STATUS not found in System

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 
  • 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 Foswiki is running.

  • Download the ZIP file from the Plugin web (see below)
  • Unzip in your Foswiki installation directory. Content:
    File: Description:
    data/System/ForEachPlugin.txt Plugin topic
    data/System/ForEachPlugin.txt,v Plugin topic repository
    lib/Foswiki/Plugins/ Plugin Perl module
  • Test if the installation was successful:
    • enter samples here

Plugin Info

Plugin Author: Original 2005: Magnus Lewis Smith - From 2009 Kenneth Lavrsen and put in Feel Free to Modify policy
Release: 1.102
Version: 10382 (2010-12-22)
Change History:  
22 Dec 2010: (1.102) Foswikitask:Item10183 - Add link to Foswiki:Support.Faq39
10 Nov 2010: (1.101) Foswikitask:Item9993 - Fix Release Version
04 Jun 2009: (1.100) Ported unmodified to Foswiki by Kenneth Lavrsen
28 Sep 2005: (1.000) Initial version
Foswiki Dependency: $Foswiki::Plugins::VERSION 1.024
CPAN Dependencies: none
Other Dependencies: none
Perl Version: 5.008
License: GPL (GNU General Public License)
Plugin Home:

Related Topics: SitePreferences, Plugins
Topic revision: r1 - 04 Jun 2009, ProjectContributor
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