Decision

Decision steps are used to take different routes through the application depending on the contents of variables or data sources.

Decision steps are invisible to the operator. To allow the operator to decide which route to take in a application, use a User step in conjunction with a decision step.

Outgoing routes To configure the outgoing routes for a Decision step, start by connecting the decision step element to two or more items, then double-click on the little cogwheels that appear after the decision step. Route conditions Each route has to define one or more conditions for when the route should be taken. The order in which these conditions are evaluated is not defined, except that the default route is always taken last. (See below.)

Conditions come in two types: Binary and unary. Binary conditions compare one value (L-value or left hand side value) to another value (R-value or right hand side value). A natural language example would be "if A equals B" where A is the L-value and B is the R-value. Unary conditions only have an Lvalue; an example would be "if A exists".

The following condition types are available for variables:

• Equals: Holds true if the variable is equal to the comparison value.

• NotEquals: Holds true if the variable is different from the comparison value.

• GreaterThan and LessThan: Hold true if the variable is greater or less than the comparison value (only works for numeric values).

• IsTrue: Holds true if the variable value is different from 0.

• IsFalse: Holds true if the variable value is 0.

• IsNull: Holds true if the variable is empty.

• IsNotNull: Holds true if the variable is not empty.

The following condition types are available for data sources:

• IsEmpty: Holds true if the data source is empty (e.g. the underlying SQL query returns no results).

• IsNotEmpty: Holds true if the data source is not empty.