The Transformer version 8.x expression editor is not the same expression editor as the one used in Framework Manager or the Web studios.
The expression editor can be invoked from a number of places within Transformer. The functionality varies depending upon whether you are creating a calculated dimension, calculated category, calculated column or calculated measure.
An expression is any combination of operators, constants, functions, and other components that evaluates to a single value. You build expressions to create calculations. A calculation is an expression that you use to create a new value from existing values contained within a data item.
An expression can include
functions, such as Day and Months-Between
The Functions folder in the Available Components box contains functions provided by Transformer. These are pre-defined calculations, such as string, numeric, and date calculations, that are designed to operate on various data types.
constants, such as numbers, strings, and date
Constants are typed directly into the expression once the type of value is determined. Remember to press Enter to complete the entry.
The expression editor is context-sensitive, so it presents only options that are relevant at each stage of expression building.
operators, such as +
Operators specify what happens to the values on either side of the operator. There are four types:
mathematical operators perform mathematical operations on two parts of an expression (for example: +, -, *, /, ^)
string operators concatenate two character strings (+)
logical operators define a relationship between two parts of an expression (for example: and, not, or)
comparison operators filter data by comparing one or more values that you enter against the values in the expression (for example: like, =)
Note: Transformer supports mathematical operators and string concatenate operators. It also supports logical operators and comparison operators, but only in an if-then-else conditional construct.
the if-then-else conditional construct
You can build expressions in four functional areas in Transformer:
calculated columns in a data source
calculated categories
calculated measures
calculations that apply to a set of categories or levels within a dimension
The components that are available to build an expression depend on:
the type of calculation
the type of data class (numeric, date, or text)
the type of data column
whether the calculation includes an if-then-else conditional construct
As you add or type each component in the expression, the syntax is evaluated against mathematical rules. The Tips window of the expression editor provides information about the selected component.