/// <summary>
/// Add merge views for any views in the chain requiring a merge (group view).
/// Appends to the list of view specifications passed in one ore more
/// new view specifications that represent merge views.
/// Merge views have the same parameter list as the (group) view they merge data for.
/// </summary>
/// <param name="specifications">is a list of view definitions defining the chain of views.</param>
/// <exception cref="ViewProcessingException">indicating that the view chain configuration is invalid</exception>
internal static void AddMergeViews(IList <ViewSpec> specifications)
{
if (Log.IsDebugEnabled)
{
Log.Debug(".addMergeViews Incoming specifications=" + specifications.Render());
}
// A grouping view requires a merge view and cannot be last since it would not group sub-views
if (specifications.Count > 0)
{
var lastView = specifications[specifications.Count - 1];
var viewEnum = ViewEnumExtensions.ForName(lastView.ObjectNamespace, lastView.ObjectName);
if ((viewEnum != null) && (viewEnum.Value.GetMergeView() != null))
{
throw new ViewProcessingException(
"Invalid use of the '" +
lastView.ObjectName +
"' view, the view requires one or more child views to group, or consider using the group-by clause");
}
}
var mergeViewSpecs = new LinkedList <ViewSpec>();
foreach (var spec in specifications)
{
var viewEnum = ViewEnumExtensions.ForName(spec.ObjectNamespace, spec.ObjectName);
if (viewEnum == null)
{
continue;
}
var mergeView = viewEnum.Value.GetMergeView();
if (mergeView == null)
{
continue;
}
// The merge view gets the same parameters as the view that requires the merge
var mergeViewSpec = new ViewSpec(
mergeView.Value.GetNamespace(), mergeView.Value.GetName(),
spec.ObjectParameters);
// The merge views are added to the beginning of the list.
// This enables group views to stagger ie. Marketdata.Group("symbol").Group("feed").xxx.Merge(...).Merge(...)
mergeViewSpecs.AddFirst(mergeViewSpec);
}
specifications.AddAll(mergeViewSpecs);
if (Log.IsDebugEnabled)
{
Log.Debug(".addMergeViews Outgoing specifications=" + specifications.Render());
}
}
public void TestForName()
{
ViewEnum?enumValue = ViewEnumExtensions.ForName(
ViewEnum.CORRELATION.GetNamespace(),
ViewEnum.CORRELATION.GetName());
Assert.AreEqual(enumValue, ViewEnum.CORRELATION);
enumValue = ViewEnumExtensions.ForName(ViewEnum.CORRELATION.GetNamespace(), "dummy");
Assert.IsNull(enumValue);
enumValue = ViewEnumExtensions.ForName("dummy", ViewEnum.CORRELATION.GetName());
Assert.IsNull(enumValue);
}
