Transformations
A set of built-in transformations are available to coerce strings to other data types. The transformations can be applied to any string, including strings resulting from the resolution of configurations tokens.
After transformation, the JSON node representing the transformation is replaced by the result value.
The following sections describe how to use transformations, and describe the transformations available:
Usage
{
"$transformation": string or transformation
}
A transformation is a JSON object with a required main attribute, starting with
a $
. The following example transforms a string to an integer:
{"$int": string}
The value of a transformation value can be a JSON string or another transformation that results in a string. The following example shows a nested transformation:
{
"$array": {
"$base64:decode": string
}
}
The input string must match the format expected by the transformation. In the
previous example, because the final transformation is to an array, the input
string must be a string that represents an array, such as
"[ \"one\", \"two\" ]"
.
In the first transformation, the encoded string is transformed to a
base64-decoded string. In the second, the string is transformed into a JSON
array, for example, [ "one", "two" ]
.
array
{"$array": string}
Returns a JSON array of the argument.
- string
-
String representing a JSON array.
- array
-
JSON array.
The following example transformation results in the JSON array
[ "one", "two" ]
:
{"$array": "[ \"one\", \"two\" ]"}
bool
{"$bool": string}
Returns a Boolean with a value represented by the argument.
Returns true
if the input value equals "true"
(ignoring case). Otherwise,
returns false
.
- string
-
String containing the boolean representation.
- boolean
-
Boolean value represented by the argument.
If the configuration token &{capture.entity}"
resolves to "true"
, the
following example transformation results in the value true
:
{"$bool": "&{capture.entity}"}
decodeBase64
{
"$base64:decode": string,
"$charset": "charset"
}
Transforms a base64-encoded string into a decoded string.
If $charset
is specified, the decoded value is interpreted with the character
set.
- string
-
Base64-encoded string.
$charset
-
The name of a Java character set, as described in Class Charset.
- string
-
Base64-decoded string in the given character set.
The following example transformation returns the Hello
string:
{
"$base64:decode": "SGVsbG8=",
"$charset": "UTF-8"
}
encodeBase64
{
"$base64:encode": string,
"$charset": "charset"
}
Transforms a string into a base64-encoded string. Transforms to null
if the
string is null
.
If $charset
is specified, the string is encoded with the character set.
- string
-
String to encode with the given character set.
$charset
-
The name of a Java character set, as described in Class Charset.
- string
-
Base64-encoded string.
int
{"$int": string}
Transforms a string into an integer.
If the parameter is not a valid number in radix 10, returns null
.
- string
-
String containing the integer representation.
- int
-
Integer value represented by the argument.
The following example transformation results in the integer 1234
:
{"$int": "1234"}
list
{"$list": string}
Transforms a comma-separated list of strings into a JSON array of strings
- string
-
A string representing a comma-separated list of strings.
- array
-
The JSON array of the provided argument. Values are not trimmed of leading spaces.
The following example transformation results in the array of strings
["Apple","Banana","Orange","Strawberry"]
:
{"$list": "Apple,Banana,Orange,Strawberry"}
The following example transformation results in the array of strings
["Apple"," Banana"," Orange"," Strawberry"]
, including the untrimmed spaces:
{"$list": "Apple, Banana, Orange, Strawberry"}
The following example transformation results in the array of strings
["1","2","3","4"]
, and not an array of JSON numbers [1,2,3,4]
:
{"$list": "1,2,3,4"}
number
{"$number": string}
Transform a string into a Java number, as defined in Class Number.
- strings
-
A string containing the number representation.
- number
-
The number value represented by the argument.
The following example transformation results in the number 0.999
:
{"$number": ".999"}
object
{"$object": string}
Transforms a string representation of a JSON object into a JSON object.
- string
-
String representation of a JSON object.
- object
-
JSON object of the argument.
The following example transformation
{"$object": "{\"ParamOne\":{\"InnerParamOne\":\"InnerParamOneValue\",\"InnerParamTwo\": false}}"}
results in the following JSON object:
{
"ParamOne": {
"InnerParamOne": "myValue",
"InnerParamTwo": false
}
}