Expressions in Calculator

Expressions allow you to include the following elements:

• References to other fields of the input dataset (via field names) or other expressions previously computed in the same Calculator node (via expression names). To avoid errors, make sure the expression you are referencing appears higher than the current one in the expression list.
• References to variables on the input port. (Use the Var. prefix to access input variables.)

Note: Names of fields, variables, and expressions are case-insensitive.

• Parentheses that define the order of operations
• Mathematical and relational operators
• Logical operators (and, or, not, or xor) and values (true (1) and false (0))
• Functions as described in the syntax reference (see Function List)
• String expressions in double quotes (e.g., "string expression")
• Integer and real numbers
• Single-line and multi-line comments

Note: Mathematical operations (such as addition or subtraction) on the date/time data may produce a real number with a fractional part. By default, the result equals the number of days (integer part) and the number of hours (fractional part). For example, the subtraction operation 02.01.2020 12:00 - 01.01.2020 00:00 returns 1.5. The node will interpret it as one full day (24 hours) and 12 hours.

Caching

Enable caching in Calculator expressions when you use the Data() function for recursive value computation.

We also recommend to use caching with functions whose result depends on the time of computation, such as Random(), Today(), and similar functions.

Code pane toolbar

The code pane toolbar provides several commands for quick and convenient access.

•  Preview (F3): Use this button to display up to 100 rows of the result table for calculation check.
  •  Console: Open this pane at the bottom of the Preview window to view errors found during expression evaluation. If there are no errors, the Console pane remains empty.
    • Use the  Show and  Hide buttons on the top right to expand or collapse the Console pane.
• Logical operators:
  • AND: Logical AND
  • OR: Logical OR
  • NOT: Logical NOT
  • XOR: Logical XOR (exclusive OR)
• Comparison operators:
  • = (equal to)
  • <> (not equal to)
  • < (less than)
  • > (greater than)
  • <= (less than or equal to)
  • >= (greater than or equal to)
• Templates:
  •  Number: Enter a real number. (The command inserts 0.0 into the expression code.)
  •  String: Enter a string value (inserts "").
  •  Date: Enter a date (inserts StrToDate("____-__-__", "YYYY-MM-DD")).
  •  Time: Enter a time value (inserts StrToDate("__:__:__", "HH:NN:SS")).
• Logical values:
  • FALSE: Insert False
  • TRUE: Insert True

Comments

The Calculator supports two types of comments:

• Single-line comment: Begin these with //. The comment continues to the end of the line.
• Multi-line comment: Begin these with /* and end them with */. The comment includes all the characters in between.

In the code area, use Ctrl + / to comment or uncomment code.

// Single-line comment example.

IF(IsNull(gate_one),gate_two,gate_one) // a single-line comment continues to the end of the line.

/* A multi-line comment
   includes all characters
   between slash-asterisk
   and asterisk-slash. */

Read on: JavaScript Syntax in Calculator