Transform Classes

It is possible to define any number and type of new transformation classes with specialized configurations. Rierino is shipped with the following default classes:

Payload Manipulation

Add Value To Payload

This class(com.rierino.handler.transform.AddToPayloadTransform) extends a selected payload element with a constant Json node provided as string.

Parameter	Definition	Example
element	Json path of payload element to create / extend	parameters
value	Json string to extend element with	{"test":false}

Transform Payload with JMESPath

This class(com.rierino.handler.transform.JMESPayloadTransform) transforms event payload using a JMESPath pattern.

Parameter	Definition	Example
pattern	JMESPath pattern to calculate value	{language:parameters.language, currency:parameters.currency}
patternElement	Json path to payload element which defines JMESPath pattern to calculate value	parameters.pattern
extend	Whether calculated value should replace payload or extend it	true
store	Whether JMESPath expression should be cached for future executions (defaults to true)	false
inputElement	Json path for the input element to transform	parameters
outputElement	Json path to output calculated results	result
errorAs	Element to include error message on, if the pattern fails	error

JMESPath — JMESPath

JMESPath Page

Transform Payload Array with JMESPath

This class(com.rierino.handler.transform.JMESArrayPayloadTransform) transforms array elements of an event payload using a JMESPath pattern with access to a parent data element as well (which is not supported by JMESPath out of box).

Parameter	Definition	Example
pattern	JMESPath pattern to calculate value	{parentValue: data.value, entryValue: entry.value}
patternElement	Json path to payload element which defines JMESPath pattern to calculate value	parameters.pattern
dataElement	Json path to payload element which will populate "data" field in JMES input	parameters.parent
arrayElement	Json path to payload element which is an array will populate "entry" field in JMES input with each of its entries	parameters.results
entryPath	Json path to extract specific element from array "entry" to simplify JMESPath patterns	data.main
filter	Whether JMESPath returns a boolean value for filtering arrayElement only (defaults to true)	false
excludeNulls	Whether null results should be excluded from JMESPath results (defaults to true)	false
outputElement	Json path to output results on event payload (null replaces arrayElement itself)	output
store	Whether JMESPath expression should be cached for future executions (defaults to true)	false
errorAs	Element to include error message on, if the pattern fails	error

Add Expression To Payload

This class(com.rierino.handler.transform.AddExpToPayloadTransform) adds the result of an expression to event payload.

Parameter	Definition	Example
element	Json path of payload element to use / extend	date
as	Json path to return results in (null for replacing element)	result
expression	Expression to execute	now

This transformation allows additional parameters based on the expression value:

replace

Replaces given char sequence in element with a new char sequence.

Parameter	Definition	Example
target	Text to find	old
replacement	Text to replace with	new

replaceAll

Replaces all matchings of a regex in element with a new char sequence.

Parameter	Definition	Example
target	Regex to find	[0-9]
replacement	Text to replace with	0

regex

Replaces named parameters found from a regex in element with given pattern.

Parameter	Definition	Example
target	Regex to find	/source/(?<folder>\\w+)/(?<file>\\w+)
replacement	Pattern to replace with	/target/${folder}/${file}

substring

Returns substring from element.

Parameter	Definition	Example
beginIndex	Char index to start from	0
endIndex	Char index to end with (null means till the end)	5

split

Splits element into an array with a given delimiter.

Parameter	Definition	Example
delimiter	Regex delimiter to use	,

join

Joins an element array with a given delimiter.

Parameter	Definition	Example
delimiter	Delimiter to join elements	,

concat

Concatenates element with a prefix and/or suffix.

Parameter	Definition	Example
prefix	Prefix to append	pre_
suffix	Suffix to append	_post

kv

Performs a lookup for configuration parameter value - such as secrets or connection parameters.

Parameter	Definition	Example
parameter	Parameter reference	rierino.mongo.main.uri
type	Lookup/injection type (static, dynamic, both)	static

Lookup & Map within Payload

This class(com.rierino.handler.transform.LookupPayloadTransform) traverses a list of ids in event payload and enriches them with another list matching on ids.

Parameter	Definition	Example
lookup	Json path of payload element to lookup from	lookup
lookupId	Name of id fields in lookup array	id
traverse	Json traverse expression of payload element to enrich	list.*
traverseId	Name of id fields in traverse entries	id
as	Name of field to inject lookup values in traversed path (null for merged results)	-

Use Script on Payload

This class(com.rierino.handler.transform.ScriptingPayloadTransform) allows using scripting languages to transform event payload.

Parameter	Definition	Example
script	Full scripting code returning output (or editing event payload directly)	value * 2
language	Scripting engine to use (if helperClass is not defined)	groovy
helperClass	Java class name for the scripting engine helper	com.rierino.handler.util.helper.JavaScriptHelper
nodePath	Json path to the input node in event payload	parameters
paramsPath	Key-value pairs for passing multiple variables from different Json paths	foo=data.in,bar=data.val
outputPath	Json path to output on event payload	data.output

Generate ID in Payload

This class(com.rierino.handler.transform.GenerateIDTransform) uses an ID generator to create a unique ID inside the payload.

Parameter	Definition	Example
element	Json path to add generated id on	id
generator	ID generator class	com.rierino.handler.util.generator.NumberIDGenerator
generatorId	assigned to generator	product_gen
version	ID generator version to use	1
*	All additional parameters that are applicable for the ID generator class	numberGenerator=com.rierino.handler.util.generator.EpochNumberGenerator

ID generators are cached inside GenerateIDTransform by generatorId value, so, parameter changes are not applied unless the service is restarted or version parameter value is updated. Both actions create a new instance of the generator.

Copy In Payload

This class(com.rierino.handler.transform.CopyInPayloadTransform) copies data from one section of payload to another.

Parameter	Definition	Example
from	Json path to copy from	parameters.filters
to	Json path to copy to	filters
move	Whether element should be moved instead of a copy	true

Remove From Payload

This class(com.rierino.handler.transform.ReducePayloadTransform) removes list of elements from event payload.

Parameter	Definition	Example
list	Comma separated list of Json paths to remove	product.metadata,product.internal

Do Nothing

Thıs class(com.rierino.handler.transform.NoopTransform) performs no action on the event, and is typically used as a placeholder.

Metadata Access

Add Error To Payload

This class(com.rierino.handler.transform.AddErrorToPayloadTransform) copies event error details to event payload.

Parameter	Definition	Example
element	Json path of payload element to create / extend	error

Add Metadata To Payload

This class(com.rierino.handler.transform.AddMetaToPayloadTransform) copies request metadata to event payload as "meta" element.

Append Partition To Payload

This class(com.rierino.handler.transform.AppendPartitionToPayloadTransform) appends partition digits from a payload element to another payload element. Typically used for creating a linked entity with the same partition as a master entity.

Parameter	Definition	Example
from	Json path for id to get partition digits from	guest.id
to	Json path to add partition digits to	basket.id
char	Delimiter before the partition digits	-

Add Event Parameter To Payload

This class(com.rierino.handler.transform.EventParameterToPayloadTransform) copies list of elements from full event contents to payload. Parameters defined for this transform step act as key value pairs, where keys are the target payload paths and values are the event source content paths (e.g. sessionId=requestMeta.sessionId).

Add Request Id To Payload

This class(com.rierino.handler.transform.RequestIdToPayloadTransform) adds requestId to event payload.

Parameter	Definition	Example
element	Json path of payload element to create / extend	requestId

Set Event Result

This class(com.rierino.handler.transform.SetResultTransform) resets the result data of an event, typically used for returning specific contents in case of an error.

Parameter	Definition	Example
status	Result status to set for the event	FAIL
errorPattern	JMES pattern to apply on event payload to return error contents	{"failId": id}
errorCode	Error code to return for the event	123
errorMessage	Error message to return for the event	Could not find requested id
errorHttp	Http error code to return for the event	404

Add Claims To Payload

This class(com.rierino.handler.transform.AddClaimsToPayloadTransform) adds claims from request metadata (if configured in gateway token) to event payload.

Parameter	Definition	Example
element	Json path of payload element to create / extend (claims as default)	user