URLPARAM{"name"} -- get value of a URL parameter

  • Returns the value of a URL parameter.
  • Syntax: %URLPARAM{"name"}%
  • Supported parameters:
    Parameter: Description: Default:
    "name" The name of a URL parameter required
    newline="$br" Convert newlines in textarea to other delimiters. Variables $br (for <br /> 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 ENCODE for details. encode="safe"
    encode="html" Encode special characters into HTML entities. In addition to encode="entity", it also encodes space, newline (\n) and linefeed (\r). Useful to encode text properly in HTML input fields. encode="safe"
    encode="url" Encode special characters for URL parameter use, like a double quote into %22 encode="safe"
    If set, gets all selected elements of a <select multiple="multiple"> 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)
    format="..." Format the result. $value expands to the URL parameter. If multiple is specified, $value expands to the result of the concatenated items. "$value"
    default="..." Default value in case parameter is empty or missing. The format parameter is not applied. empty string
  • Example: %URLPARAM{"skin"}% returns print for a .../view/TWiki/VarURLPARAM?skin=print URL
  • ALERT! Notes:
    • IMPORTANT: There is a risk that this variable can be misused for 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 should be encoded as "html".
      Example: <input type="text" name="address" value="%URLPARAM{ "address" encode="html" }%" />
    • Double quotes in URL parameters must be escaped when passed into other TWiki variables.
      Example: %SEARCH{ "%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 %URLPARAM{ in the value of a URL parameter, it will be modified to %<nop>URLPARAM{. This is to prevent an infinite loop during expansion.
  • Category: DevelopmentVariables, SystemInformationVariables
  • Related: ENCODE, ENTITY, SEARCH, FormattedSearch, QUERYSTRING
Topic revision: r9 - 2012-11-15 - TWikiContributor
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