To define a mapping rule in which the input for the destination
node is provided by the return value of a function and not from a
source node:
Procedure
Select the Functions tab. In the Functions tab,
the list of available functions is displayed.
In the Functions tab, expand folder
that contains the function to assign to the destination node. This
function must have no input parameters. For example, the Get Current
Date and Time function has no parameters and returns the current
date and time.
Select the function icon and drag it into the Mapping Editors
middle pane, near the destination node you want to map.
In the Mapping Editor, drag from the function icon to the
destination node. A link from the function to the destination node
is displayed.
Optional: Test if the mapping rule is valid
by right-clicking on the function in the mapping rule and selecting Apply
Function Graph. If the mapping rule is valid, the square
function icon in the graphical representation of the mapping link
is not displayed and a function icon is shown to the left of the destination
node icon, as shown in Figure 1.