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IDL Reference Guide: iTools Object Classes |
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The IDLitParameter::OnDataChangeUpdate method is called when a data value has been updated or a new data object has been associated with the visualization object.
| Note A visualization class based on the IDLitVisualization class must implement this method in order for changes or additions to the data parameters to be updated automatically in the resulting visualizations. |
Obj->[IDLitParameter::]OnDataChangeUpdate, Data, ParameterName
An object reference to the IDLitData object or the IDLitParameterSet object containing the changed parameter data. If Data is an IDLitParameterSet object, the ParameterName argument must be set to the string '<PARAMETER SET>'.
An upper-case scalar string containing the name of the parameter that has changed. The parameter specified via this argument must be registered with the visualization object. If oData is an IDLitParameterSet object, this argument must be set to the string '<PARAMETER SET>'.
None
Normally, an implementation of this method will contain a CASE statement that switches based on the value of the ParameterName argument. For example, the following code handles a parameter named Z:
PRO MyVis::OnDataChangeUpdate, oData, ParameterName
CASE ParameterName OF
'Z': BEGIN
;; do something with the z data
END
'<PARAMETER SET>': BEGIN
oZ = oData->GetByName('Z')
;; do something with the z data.
END
ENDCASE
END
| Note The Z parameter is handled twice — once if supplied as an individual IDLitData object and once if supplied via the IDLitParameterSet object. |
See Creating an OnDataChangeUpdate Method in the section Creating a New Visualization Type for more discussion of the OnDataChangeUpdate method.
IDL Online Help (March 06, 2007)