START

START node is obligatory for every scenario!

This node defines input variables for the scenario. Variables can be defined manually in a settings panel or imported in a JSON or CSV format. It is also possible to define validators for specified input variables, which ensures that proper values are submitted.

Example of input variables in CSV format:

true;var3;DOUBLE;;
true;var4;aa#bb#cc;;

Columns of this CSV contain, respectively, an information whether the variable is required, variable name, type, description and tags.

Available types: STRING, DOUBLE, INTEGER, DICTIONARY, MAP, VECTOR, BOOLEAN

Parameters of the node:

• Variables (adding / removing))

  • Variable type, name, description (shown as a field description in a form)

  • Possible values of dictionaries

  • required / non-required

• Validators

  • Define validator per variable; multiple validators available

  • If the validation fails, the engine returns an error (HTTP 400)

  • We can define a custom error description providing it as a Groovy/Python/R script result

  • Any returned value other than logical true is treated as failure of the validation

• Variable definition import from JSON file

Example of validation code (verification of variable length):

if ((object as String).length()!=32) {
    result=’Error. Incorrect string length.’
}
else {
    result=true
}
return result

Complex variable validation

In case we need validate complex types (MAP, VECTOR) there is validation API based on JSON Schema (https://json-schema.org/) or Swagger / OpenAPI.

In case of successful validation, we return the boolean value true, otherwise we return a text containing an error message. The message will be returned in the API response.

JSON Schema validator example

import com.algolytics.sce.core.scenario.validator.JsonSchemaValidator
def schemaStr = '''
    <JSON Schema for the variable>
'''
errors = JsonSchemaValidator.validate(object, schemaStr)
if (errors.size() > 0) {
    return errors.toString()
} else {
    return true
}

Swagger validator example

​import com.algolytics.sce.core.scenario.validator.*
import org.openapi4j.core.validation.ValidationSeverity
def schemaStr = '''
    <Swagger for the variable>
'''
validationData = OpenApi3Validator.validateForJson(object, schemaStr, 'AlgolyticsRequestZonk')
if (validationData.isValid()) {
    return true
} else {
    return validationData.results().items(ValidationSeverity.ERROR).toString()
}