Expressions

Expressions specify how to find or calculate a value when the report runs. Properties of a print template item that can be configured using expressions are located in the Expressions Panel . To learn more about how to configure a property with an expression see the Expression Editor.

Expressions allow you to:

• Compute complex values.
• Build complex strings.
  • For example, you could use an expression to build a phrase with embedded data values, or you could build the URL for an image that you want to include in a print template.
• Use conditional values in a print template.

Expression Components

Expressions inGeocortex Print Designer can be made up of one or many of the following components:

• Functions
• Operators
• Literals
• Parameters

To see a complete list of the operators, literals, and functions that you can use in expressions, see Operators, Literals, and Functions.

Syntax of Expressions

Follow the syntax conventions below when you create expressions:

• Type a question mark (?) before query parameter names, for example: ?queryparameter

• Add the Parameters prefix before print parameters names, for example: [Parameters.printparameter]

• Enclose string literals in single quotes ('), for example: 'USA'

  The use of quotation marks ("), for example, "Quoted Text", results in an error.

• To embed an apostrophe into a string literal, type two apostrophes, for example: 'It''s an example'

• The Boolean literals are True and False.

• Enclose date-time literals in hash marks (#), for example: [OrderDate] >= #1/1/2016#

• Use a question mark (?) to represent a null reference (one that does not refer to any object), for example: [Region] != ?

• Use round brackets () to control the order in which an expression is evaluated, for example: 2 * ([Quantity] - 1)

• If an expression contains terms of different types, you can use dedicated functions to convert the types, for example: Max(ToDecimal([Quantity]),[UnitPrice])

• Refer to Operators, Literals, and Functions for a complete list of supported operators, literals, and functions.

Types of Expressions

String Expressions

String expressions are expressions that evaluate to a string. A complex string expression combines (concatenates) a number of string literals, and functions using the concatenation operator, +.

String literals are enclosed in single quotes, for example, 'This is a string literal'. Note that you cannot use double quotes (") instead of single quotations. To embed an apostrophe into a string literal, type a two apostrophes, for example, 'It''s an example' appears in the report as: It's an example

See also...

String Functions

Conditional Expressions

You can use conditional values in a report by using the logical function, Iif(). The Iif() function takes three arguments: a Boolean expression, a value to use if the Boolean expression evaluates to True, and a value to use if the Boolean expression evaluates to False. The arguments are separated by commas: Iif(BoolenExpression, TruePart, FalsePart).