Performs Base64 decoding of a field. The decoded value is subsequently decoded as binary representation of a string according to the charset parameter. To work with actual binary data, use ISO-8859-1 character set.

ParameterTypeRequiredDefaultDescription
asstringoptional[a]_base64Decode Name of the field in which to store the decoded value.
charsetstringoptional[a]UTF-8 The character set to use when transforming bytes to string. Validated type is java.nio.char set.Charset.
  Valid ValuesISO-8859-1
   UTF-8
field[b]stringrequired  The field on which to decode Base64 values.

[a] Optional parameters use their default value unless explicitly set

[b] The argument name field can be omitted.

Omitted Argument Names

The argument name for field can be omitted; the following forms of this function are equivalent:

logscale
base64Decode("value")

and:

logscale
base64Decode(field="value")

Behavior on Invalid Encoding

An input field that does not contain a valid Base64 encoding may result in the following behavior:

  • Characters outside the base encoding alphabet are ignored.

  • If the base encoding is invalid, the output field is not created.

  • When decoding to a code point that is invalid with respect to the selected charset, the invalid code point is replaced with a placeholder character.

Decode the Base64 value in encoded and stores it in decoded:

logscale
decoded := base64Decode(encoded)