Expression Generator

Expression Generator

About

A expression generator is a column data generator that can generate data created from:

  • other columns (known as parent columns)
  • by giving an expression (or formula).

Howto

Syntax

columns:
  - name: columnName
    DataGenerator:
      type: expression
      ColumnParents: 
           - columnParentName1 # variable x
           - columnParentName2 # variable y
           - ...... # variable "z", "a", "b", "c", "d","e","f"
      expression: "javascriptExpression"  # See below for example
Mandatory Key Description
ColumnParents The column generator used in the expression
expression The expression in javascript where the parents columns maps by order to the following variables “x”, “y”, “z”, “a”, “b”, “c”, “d”,“e”, “f”

How to hide intermediate columns ?

When creating an expression generator, you may want to create columns that should not appear in the data generated. For this purpose, you can use the hidden property.

Example:

- name: columnToHide
  Hidden: true  # The column will not be added to the output.
  Description: An hidden column
  DataGenerator:
    type: entity

Snippet of expression

This section is showing snippet of expression (Javascript).

Time

  • Month where x represents the date value of the first parent columns
x.getMonth()+1 // Month
  • Month names. The below snippet use a date column as parent and lookup an array to get the month name.
var monthNames = ['Jan', 'Feb', 'Maa', 'Apr', 'Mei', 'Jun', 'Jul', 'Aug', 'Sep', 'Okt', 'Nov', 'Dec']; 
monthNames[x.getMonth()]
  • Year number
x.getFullYear()

Email

Email String concatenation where:

  • x would be a name from the first parent column
  • y would be a company name from the second parent column
  • z would be a TLD domain extension (.com, …)
x+'@'+y+'.'+z

Data Type

The below data type are supported:

Data Type
Integer
Float
Double
Numeric
Decimal
Date
Timestamp
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