Requesting Data

Data can be refreshed from multiple points throughout the display/parameter hierarchy.  The simplest point to refresh data is a call to DisplayViewModelBase.RefreshData, which will automatically request data for all parameters on the display using the current time range.  Individual IParameterSetControllers can also have data refreshed individually, which may be useful when a parameters display option changes.

The refresh of data is a ‘fire and forget’ call, meaning that the call will immediately return.  The data request sub-system will run through a data request pipeline before updating a data result on the individual IParameterController.  Notification of new data being available on a parameter is achieved by the events IParameterController.DataResultChanged or IParameterController.SampleDataResultChanged, the data result property on the parameter can then be queried.