Chapter 3: Data Management 57
iTool Developer’s Guide iTool Data Objects
In this example we do not specify an iTool data type for the data container object
itself.
Tip
Often, you will organize data using a subclass of the IDLitDataContainer class: the
IDLitParameterSet.
See “IDLitDataContainer” (IDL Reference Guide) for a complete description of the
data container object, its methods, and its properties.
Parameter Sets
The IDLitParameterSet class is a specialized subclass of the IDLitDataContainer
class that provides the ability to associate parameters with the contained IDLitData
and IDLitDataContainer objects. This association allows the iTool developer to
package a set of data parameters in a single container, which is then provided to the
iTools system for processing and display. See “IDLitParameterSet” (IDL Reference
Guide) for a complete description of the parameter set object, its methods, and its
properties.
Note
Do not confuse parameter sets, which are containers for data objects, with
parameters, which define how data is used by a visualization object. Parameters are
described in “Parameters” on page 61.
Using a parameter set object is very similar to using a data container object. The
parameter set itself is created using standard IDL object-creation syntax. The
parameter set object allows for the association of a parameter with each added data
object. For example, the following statements create a new parameter set and add the
data object created in the previous section, assigning a parameter:
; Create a parameter set object
oParameterSet = OBJ_NEW('IDLitParameterSet')
; Add a data object, assigning a parameter
oParameterSet->Add, oData, PARAMETER_NAME = 'Y data'
