Get current cache outside of graph - acumatica

Question

I've created a custom selector that has logic which depends on the value of a field in a header section of a screen. Since the logic is not in the graph which holds the views, how would I obtain the current value of the cache for this header section? I've set the field I'm referencing in the header to commitchanges=true and I've even put SyncPosition=true in the header section of the page. The following logic does not give me the current value that is (I'm assuming) in the cache:
mh = (xTACMappingHeader)PXSelect< xTACMappingHeader,
Where< xTACMappingHeader.mappingName, Equal<Required<xTACMappingDetail.mappingName>>>>.Select(new PXGraph<FinancialTranslatorMaint>(), md.MappingName);
What's the best way to retrieve the current value of the cache in a graph outside of that graph?
Thanks...

Answer 1

You get hold of graph using CacheAttached event. See example below.
public class YourAttribute : PXEventSubscriberAttribute
{
private PXGraph _Graph = null;
public override void CacheAttached(PXCache sender)
{
_Graph = sender.Graph;
base.CacheAttached(sender);
}
}

Answer 2

PXCache objects never exist outside of graph. You can access current graph through the _Graph field of PXCustomSelectorAttribute:
protected PXGraph _Graph;
something like:
mh = (xTACMappingHeader)PXSelect<…>.Select(_Graph, md.MappingName);
to access current value of the cache:
_Graph.Caches[typeof(YourDAC)].Current
While initializing caches, Acumatica Framework invokes CacheAttached() method on for every field attribute. PXCustomSelectorAttribute assigns value for the _Graph field based on Graph property of the currently initializing PXCache object:
public class PXCustomSelectorAttribute : PXSelectorAttribute
{
...
public override void CacheAttached(PXCache sender)
{
...
_Graph = sender.Graph;
...
}
...
}