Livecycle

Creating basic calculations

About basic calculations

Simple expressions are the most basic instances of scripting. These expressions do not involve using FormCalc built-in functions and are never more than a single line in size. You must add simple expressions to the calculate event of a particular field or object in order for the value of the expression to output onto your form.

Examples of basic calculations

These are all examples of simple expressions:

2

“abc”

2 – 3 * 10 / 2 + 7

Each simple expression evaluates to a single value by following a traditional order of operations, even if that order is not always obvious from the expression syntax. For example, the following sets of expressions produce equivalent results:

 

Expression	Equivalent to	Result
“abc”	“abc”	abc
2 – 3 * 10 / 2 + 7	2 – (3 * 10 / 2) + 7	-6
(10 + 2) * (5 + 4)	(10 + 2) * (5 + 4)	108
0 and 1 or 2 > 1	(0 and 1) or (2 >1)	1 (true)
2 < 3 not 1 == 1	(2 < 3) not (1 == 1)	0 (false)

As implied in the previous table, all FormCalc operators carry a certain precedence when they appear within expressions. The following table illustrates this operator hierarchy.

 

Precedence	Operator
Highest	=
	(Unary) – , + , not
	* , /
	+ , -
	< , <= , > , >= , lt , le , gt , ge
	== , <> , eq , ne
	& , and
Lowest	| , or

All of the previous examples are valid, simple expressions that you can add to a form field or object that will accept calculations and scripts. For example, if you create a new form in LiveCycle Designer ES with a single numeric field, add the following calculation to the calculate event in the Script Editor.

Then, when you click the Preview PDF tab to view the completed form, the value of the simple expression appears in the text field.

If the value does not appear in the preview, ensure that your simple expression appears in the calculate event of the form design object. You need to also ensure that you installed LiveCycle Designer ES and Acrobat correctly.

Creating basic calculations