VarENCODE < TWiki

#VarENCODE
---+++ ENCODE{string} -- encode a string to URL or HTML entities
   * Encode "special" characters to HTML numeric entities or to URL entities.
   * Encoded characters:
      * 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: =%<nop>ENCODE{"string"}%=
   * Supported parameters:
     | *Parameter:* | *Description:* | *Default:* |
     | ="string"= | String to encode | required (can be empty) |
     | =type="url"= | Encode special characters for URL parameter use, like a double quote into =%22= | (this is the default) |
     | =type="quotes"= | Escape double quotes with backslashes (=\"=), does not change other characters. This type does not protect against cross-site scripting. | =type="url"= |
     | =type="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. | =type="url"= |
     | =type="safe"= | Encode special characters into HTML entities for cross-site scripting protection: ="<"=, =">"=, ="%"=, single quote (='=) and double quote (="=) are encoded. | =type="url"= |
     | =type="entity"= | Encode special characters into HTML entities, like a double quote into =&amp;#034;=. Does *not* encode newline (=\n=) or linefeed (=\r=). | =type="url"= |
     | =type="entity"= %BR% =extra=" $n$r"= | For =type="entity"= only, use the =extra= parameter to encode additional characters to HTML numeric entities. [[FormatTokens][Formatting tokens]] can be used, such as ="$n"= for newline. Note that =type="entity" extra=" $n$r"= is equivalent to =type="html"=. | =type="url"= %BR% =extra=""= |
     | =type="html"= | Encode special characters into HTML entities. In addition to =type="entity"=, it also encodes space, =\n= and =\r=. Useful to encode text properly in HTML input fields. See equivalent [[%IF{"'%INCLUDINGTOPIC%'='TWikiVariables'" then="#"}%VarENTITY][ENTITY]]. | =type="url"= |
   * Examples:
      * =%<nop>ENCODE{"spaced name"}%= expands to =%ENCODE{"spaced name"}%=
      * =%<nop>ENCODE{"spaced name" type="entity" extra=" "}%= expands to =spaced&amp;#32;name=
   * __Notes:__
      * Values of HTML input fields should be encoded as ="html"=. A shorter =%<nop>ENTITY{any text}%= can be used instead of the more verbose =%<nop>ENCODE{ "any text" type="html" }%=. %BR% Example: =&lt;input type="text" name="address" value="%<nop>ENTITY{any text}%" /&gt;=
      * Double quotes in strings must be escaped when passed into other TWiki variables.%BR% Example: =%<nop>SEARCH{ "%<nop>ENCODE{ "string with "quotes"" type="quotes" }%" noheader="on" }%=
      * Use =type="moderate"=, =type="safe"=, =type="entity"= or =type="html"= to protect user input from URL parameters and external sources against [[http://en.wikipedia.org/wiki/Cross-site_scripting][cross-site scripting]] (XSS). =type="html"= is the safest mode, but some TWiki applications might not work. =type="safe"= provides a safe middle ground, =type="moderate"= provides only moderate cross-site scripting protection.
   * Category: ApplicationsAndComponentsVariables, DevelopmentVariables, ExportAndPublishingVariables
   * Related: [[%IF{"'%INCLUDINGTOPIC%'='TWikiVariables'" then="#"}%VarENTITY][ENTITY]], [[%IF{"'%INCLUDINGTOPIC%'='TWikiVariables'" then="#"}%VarFORMFIELD][FORMFIELD]], [[%IF{"'%INCLUDINGTOPIC%'='TWikiVariables'" then="#"}%VarQUERYPARAMS][QUERYPARAMS]], [[%IF{"'%INCLUDINGTOPIC%'='TWikiVariables'" then="#"}%VarURLPARAM][URLPARAM]]
This topic: TWiki > WebHome > TWikiVariables > VarENCODE
Topic revision: r7 - 2012-11-12 - TWikiContributor
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