(r7) VarURLPARAM < TWiki

Tags: view all tags

#VarURLPARAM
---+++ URLPARAM{"name"} -- get value of a URL parameter
   * Returns the value of a URL parameter.
   * Syntax: =%<nop>URLPARAM{"name"}%=
   * Supported parameters:
     | *Parameter:* | *Description:* | *Default:* |
     | ="name"= | The name of a URL parameter | required |
     | =default="..."= | Default value in case parameter is empty or missing | empty string |
     | =newline="$br"= | Convert newlines in textarea to other delimiters. Variables =$br= (for =&lt;br /&gt;= tag), =$n= (for newline) are expanded. Other text is encoded based on =encode= parameter. | no conversion |
     | =encode="off"= | Turn off encoding. See important security note below | =encode="safe"= |
     | =encode="quote"= | Escape double quotes with backslashes (=\"=), does not change other characters; required when feeding URL parameters into other TWiki variables. This encoding does not protect against cross-site scripting. | =encode="safe"= |
     | =encode="moderate"= | Encode special characters into HTML entities for moderate cross-site scripting protection: ="<"=, =">"=, single quote (='=) and double quote (="=) are encoded. Useful to allow TWiki variables in comment boxes. | =encode="safe"= |
     | =encode="safe"= | Encode special characters into HTML entities for cross-site scripting protection: ="<"=, =">"=, ="%"=, single quote (='=) and double quote (="=) are encoded. | (this is the default) |
     | =encode="entity"= | Encode special characters into HTML entities. See [[%IF{"'%INCLUDINGTOPIC%'='TWikiVariables'" then="#"}%VarENCODE][ENCODE]] for more details. | =encode="safe"= |
     | =encode="html"= | As =encode="entity"= except it also encodes newline (=\n=) and linefeed (=\r=) | =encode="safe"= |
     | =encode="url"= | Encode special characters for URL parameter use, like a double quote into =%22= | =encode="safe"= |
     | =multiple="on"= %BR% =multiple="[<nop>[$item]]"= | If set, gets all selected elements of a =&lt;select multiple="multiple"&gt;= tag. A format can be specified, with =$item= indicating the element, e.g. =multiple="Option: $item"= | first element |
     | =separator=", "= | Separator between multiple selections. Only relevant if multiple is specified | ="\n"= (newline) |
   * Example: =%<nop>URLPARAM{"skin"}%= returns =print= for a =.../view/%WEB%/%INCLUDINGTOPIC%?skin=print= URL
   * __%X% Notes:__
      * *IMPORTANT:* There is a risk that this variable can be misused for [[http://en.wikipedia.org/wiki/Cross-site_scripting][cross-site scripting]] (XSS) if the encoding is turned off. The =encode="safe"= is the default, it provides a safe middle ground. The =encode="entity"= is more aggressive, but some TWiki applications might not work.
      * URL parameters passed into HTML form fields must be entity [[%IF{"'%INCLUDINGTOPIC%'='TWikiVariables'" then="#"}%VarENCODE][ENCODEd]].%BR% Example: =&lt;input type="text" name="address" value="%<nop>URLPARAM{ "address" encode="entity" }%" /&gt;=
      * Double quotes in URL parameters must be escaped when passed into other TWiki variables.%BR% Example: =%<nop>SEARCH{ "%<nop>URLPARAM{ "search" encode="quotes" }%" noheader="on" }%=
      * 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.
      * Watch out for TWiki internal parameters, such as =rev=, =skin=, =template=, =topic=, =web=; they have a special meaning in TWiki. Common parameters and view script specific parameters are documented at TWikiScripts.
      * If you have =%<nop>URLPARAM{= in the value of a URL parameter, it will be modified to =%&lt;nop&gt;URLPARAM{=. This is to prevent an infinite loop during expansion.
   * Related: [[%IF{"'%INCLUDINGTOPIC%'='TWikiVariables'" then="#"}%VarENCODE][ENCODE]], [[%IF{"'%INCLUDINGTOPIC%'='TWikiVariables'" then="#"}%VarSEARCH][SEARCH]], FormattedSearch, [[%IF{"'%INCLUDINGTOPIC%'='TWikiVariables'" then="#"}%VarQUERYSTRING][QUERYSTRING]]

Topic revision: r7 - 2010-03-20 - TWikiContributor

Webs
TWiki

Account
- Log In
- Register User

~~Edit~~
~~Attach~~

Copyright © 1999-2025 by the contributing authors. All material on this collaboration platform is the property of the contributing authors.
Ideas, requests, problems regarding TWiki? Send feedback
Note: Please contribute updates to this topic on TWiki.org at TWiki:TWiki.VarURLPARAM.