Intrinsic Functions and Operators

Logi Analytics products include a set of intrinsic scripting functions and operators, modeled on VBScript, that provide commonly-required functionality and which are available in all "formula"-capable element attribute values. This topic identifies these functions and operators and also identifies some reserved words to be aware of.

• General Information
• Functions
• Operators

General Information

Intrinsic functions and operators are available regardless of which scripting language has been specified as the default for a Logi application, except as noted below. Formulas are expressions made up of literals, tokens, functions, and operators.

Functionnames are case-insensitive reserved words. Functions return values, which are usually the result of computations based on data and constants.

Use "Formula Attributes"

During development using Logi Studio, formulae with functions can be entered into some attribute values. So-called "formula attributes" are those whose values can evaluate a formula and/or tokens; not all attributes are formula attributes.

There is no comprehensive list of the formula attributes - mostly because not all tokens are evaluated equally, so for each attribute it's often more about what type of tokens can be evaluated, as opposed to whether tokens are evaluated at all.

A a general rule, with the exception of the ID attribute, token evaluation is supported in most attributes. However, for reasons of backward compatibility, some tokens are not evaluated in Super Element formulae. These situations are subject to periodic review and requests to make specific attributes evaluate formulae and/or tokens, or Super Element formula evaluate tokens, are welcome; please use the DevNet Enhancement Ideas area to make such a request.

The method used to indicate that an evaluation is needed depends on the attribute characteristics:

In attributes that expect a True or False value, such as the Division element's Condition attribute, shown above left, any formula entered will be automatically evaluated. Similarly, all attributes that are actually named "Formula", as in the Calculated Column element, will expect to evaluate a formula.

However, in some attributes that typically expect text, such as the Label element's Caption attribute, shown above right, a leading equals sign can be used to trigger a formula evaluation. There is no published list of the elements that fall into this category, so learning them is a matter of experience. When in doubt, try it with and without the leading equals sign.

Formulae are typically evaluated by the scripting engine, based on the scripting language set in the _Settings definition, General element. The language choice may affect a few intrinsic operators, such as those for string concatenation and logical comparison. By default, Studio's New Application Wizard sets the choice to Javascript. Formula errors will be displayed as either an empty value or "???" - when this occurs, syntax errors are a common cause. The Debugger Trace page often provides detailed information about these errors.

Use Tokens

Tokens are placeholders for data or values, and are resolved at runtime by the Logi Engine. Datalayer data is represented in formulae using @Data tokens, in this format: @Data.UnitPrice~. Tokens are case-sensitive. Some of the other tokens include @Request, @Local, and @Session.

Here are some examples of formulae using @Data tokens:

Multiply a data column by an constant value to calculate the tax applied to the price.
@Data.UnitPrice~ * .04

Get the number of days from the order date to the shipment date.
DateDiff("d", CXMLDate("@Data.OrderDate~"), CXMLDate("@Data.ShippedDate~") )

Concatenate columns and strings together, in a Label caption, language is VBScript. This might return: "Smith, John".
=@Data.LastName~ & ", " & @Data.FirstName~

Use Super-Elements

In super-elements, such as the Analysis Grid, users can build formulae at runtime in the element's user interface; functions can be part of these formulae and they're typed directly into the appropriate UI panels. Data is represented in these formulae by enclosing the column name within square brackets, for example: [UnitPrice]

Here are some examples of formulae in a super-element user interface:

Multiply two data columns, UnitPrice and Quantity, to make an ExtendedPrice column.
[UnitPrice] * [Quantity]

Get the number of weekdays since the shipment date.
DateDiff("w", [ShippedDate], Now )

Concatenate columns and strings together. Language is Javascript. This might return: "Smith, John".
[LastName] + ', ' + [FirstName]

Functions

The following table describes the intrinsic functions, which accept one or more parameters and return a single value. Double-quotes are used around string parameters and tokens that contain date/time values. In the Syntax column below, parameters in square brackets are optional.
 

Operators

The following table describes the intrinsic operators, which are used for arithmetic operations and logical comparisons. Some intrinsic operators may be overridden depending on scripting language choice, as noted.
 

You may represent true and false values as True and False.