ENCODE{string} -- encode a string to URL entities, HTML entities, CSV format, and more

  • Encode "special" characters in a string to HTML numeric entities, URL entities. Also escapes special characters for CSV use and more.
  • 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: %ENCODE{"string"}%
  • Supported parameters:
    Parameter: Description:Sorted ascending Default:
    type="url" Encode special characters for URL parameter use, like a double quote into %22 (this is the default)
    type="safe" Encode special characters into HTML entities for cross-site scripting protection: "<", ">", "%", single quote (') and double quote (") are encoded. 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="entity" Encode special characters into HTML entities, like a double quote into &#034;. Does not encode newline (\n) or linefeed (\r). type="url"
    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 ENTITY. type="url"
    type="json" Escape double quotes and backslashes with backslashes (\" and \\, respectively), escape non-printable characters with hex code \u0000 ... \u001F, does not change other characters. Use this to properly escape text for a JSON string. Example result: This is a string with \"quoted\" and \\backslashed\\ text. type="url"
    type="quotes" Escape double quotes with backslashes (\"), does not change other characters. This type does not protect against cross-site scripting. type="url"
    type="csv" Escape single quotes and double quotes by repeating them, other characters do not change. Use this to properly escape fields in CSV reports that output comma-separated values, such as "field 1","field 2 with ''single'' and ""double"" quotes". type="url"
    type="entity"
    extra=" $n$r"
    For type="entity" only, use the extra parameter to encode additional characters to HTML numeric entities. Formatting tokens can be used, such as "$n" for newline. Note that type="entity" extra=" $n$r" is equivalent to type="html". type="url"
    extra=""
    newline="..." Replace a newline with the specified value before encoding.
    Please note that newline="<br/>" does not bring <br/> to the output because < and > are encoded (except with the quotes and csv types). To have <br/> in the output, you need to specify newline="$br". However, newline="$br" does not work in combination with type="url" (the defautl type). This shouldn't be a problem because it's very rare to need to have <br/> encoded in a URL.
    In addition to $br, $n has a special meaning in a newline parameter value - $n results in a newline in the output.
    This parameter is expected to be used in combination with the moderate, safe, entity, or html type. With the other types, it causes unuseful results.
     
    "string" String to encode required (can be empty)
  • Examples:
    • %ENCODE{"spaced name"}% expands to spaced%20name
    • %ENCODE{"spaced name" type="entity" extra=" "}% expands to spaced&#32;name
  • Notes:
    • Values of HTML input fields should be encoded as "html". A shorter %ENTITY{any text}% can be used instead of the more verbose %ENCODE{ "any text" type="html" }%.
      Example: <input type="text" name="address" value="%ENTITY{any text}%" />
    • Double quotes in strings must be escaped when passed into other TWiki variables.
      Example: %SEARCH{ "%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 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: ENTITY, FORMFIELD, QUERYPARAMS, URLPARAM


This topic: TWiki > WebHome > TWikiVariables > VarENCODE
Topic revision: r9 - 18 Jun 2015 - TWikiContributor
 
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