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: 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 &#034;. Does not encode newline (\n) or linefeed (\r). 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=""
    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="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="search" Special encoding used for SEARCH: Substitute % characters into non-printable characters, so that TWikiVariables are no longer expanded. Also escapes quotes. Used to feed a search string from a URLPARAM into SEARCH without expanding any variables, such as when searching for %BR%. type="url"
    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.
     
  • 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: %SET{ "lunch" value="%ENCODE{ "string with "quotes"" type="quotes" }%" remember="1" }%
    • 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
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Topic revision: r10 - 15 Jul 2018 - TWikiContributor
 
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