Loop¶

Description

This component allows inserting loops in the flow. The loop will be repeated, as long as the given condition is met (therefore, it is a loop of type WHILE… DO).

Input Parameters

Loop accepts zero or more values, zero or more records, zero or more lists and zero or more pages. These elements are used to assign variables to the loop output condition expression. The information about available functions can be found in Appendix A.

Output Values

None.

Example

After an Extractor component has received information about several people, being one of the attributes the birth date, an example wrapper obtains information about each of the years in which this person has been alive. This is done by accessing another resource that accepts as an input the specific year to obtain information about and returns the most relevant events from that year.

Using ITPilot it is possible to construct a loop, where each iteration accesses each of the specific years. The components used in this part of the process are shown in Example of Loop component operation.

For each record obtained by the Extractor component an Expression component (Expression_1) is created that obtains the age of this person, applying the expression:

SUBTRACT(2012,GETYEAR(TODATE('MM/dd/yyyy',Record_Constructor_1_output.DATE)))

, where the date of birth is subtracted from the current date to check the age of this person (to simplify the example, only the date of birth is taken into account). The output condition of the loop can be defined like this:

AGE = 0

, where AGE is the value resulting from the previous subtraction.

Finally, another expression component (Expression_2) needs to be created within the loop to subtract 1 from the AGE expression in each iteration so the previously defined output condition can be met: SUBTRACT(AGE, 1)

Example of Loop component operation¶