Expression Evaluator#

The Expression Evaluator task performs various operations on input values to produce an output. It supports mathematical expressions through the mathjs engine, XPath queries, and Regular Expressions. It can also evaluate multiple expressions until one returns a Boolean true, similar to an if (condition) else statement.

Warning

This task is deprecated and will be removed starting with version 12. Its functionality has been split into three separate actions: Generic Expression Evaluator, Regular Expression Evaluator, and XPath Expression Evaluator.

Workflows#

Data Flow	Control Flow

Inputs#

Name	Data Type	Description
`<custom list>`	`<custom>`	Defines the input values used in the operation
Activate	`any`	Triggers the task

Outputs#

Name	Data Type	Description
`<custom list>`	`<custom>`	Defines the output values generated by the operation
Error	`Error`	Details about any error that occurs during processing

Settings#

The General tab includes standard task settings and the following parameters:

Name	Data Type	Values	Default Value	Description
Expression Type	`enum`	`Generic` `XPath` `RegularExpression`	`Generic`	Defines the type of expression to evaluate
Evaluator Behavior	`enum`	`EvaluateAll` `EvaluateUntilTrue`	`EvaluateAll`	Determines whether all expressions are evaluated or the evaluation stops when a `true` result is found
Clear Inputs	`Boolean`		false	When enabled, clears input values after the task is triggered

The Inputs Tab includes the following settings:

Name	Data Type	Description
Name	`String`	Input Name
Type	`Long` `Decimal` `DateTime` `Boolean` `String` `Integer`	Defines the input data type
Collection Type	`None` `Array` `Map`	Specifies the structure of the input
Default Value	`any`	Default value assigned to the input parameter

The Outputs Tab includes the following settings:

Name	Data Type	Description
Name	`String`	Output Name
Type	`Long` `Decimal` `DateTime` `Boolean` `String` `Integer`	Defines the output data type
Collection Type	`None` `Array` `Map`	Specifies the structure of the output
Expression	`any`	Operation applied to the input value

Note

Expressions can be tested by entering sample input values and evaluating the result.

Action Settings#

Expression Type `Generic`#

The Generic expression type uses the mathjs library, a JavaScript-based math engine. It supports mathematical operations and a subset of native JavaScript functions.

Expression Type `XPath`#

The XPath expression type searches for a specific path within an object and returns the value or an array of values corresponding to that path.

Expression Type `Regular Expression`#

The Regular Expression expression type applies a pattern to the input value and returns matching results as a single value or array.

Evaluator Behavior#

EvaluateUntilTrue: Stops processing when an expression returns a true value and outputs the corresponding result.
EvaluateAll: Evaluates all configured expressions and outputs all results.
Clear Inputs: When enabled, resets the inputs after task execution.

Note

Test mathjs expression at https://jsbin.com/devacu/edit?html,js,output. Additional documentation is available at http://mathjs.org/docs/expressions/syntax.html and http://mathjs.org/docs/reference/functions.html ⧉.

Remarks#

The Expression Evaluator provides flexible operations for transforming input data. While mathjs supports many JavaScript-like functions, it is not a full JavaScript engine; some native JavaScript code may not execute as expected.