Lazy loading, how does it work?

 

I have table Document and table File. File contains binary data and I don't want it to load unless I need this data.

 

SYSDocument.PropertyMetadata.SYSFile.ReferenceStrategy = new EntityReferenceStrategy(EntityReferenceLoadStrategy.DoNotLoad, MergeStrategy.OverwriteChanges);

After placing code above it works (entity not loaded) and no errors which proves me that my code doesn't need "File" just yet. No bindings, nothing needs it.

 

Question is, what triggers lazy loading and how I can see which line of code caused lazy loading to happen? I like the feature but also want to be able to contol it. Or at least understand why DevForce decides to load it.

 

 

 

Is there any way for me to trace who is accessing this entity to see why it's doing it? I like lazy loading behavior when I need entity but in this case it doesn't seem to be needed..

 

If you haven't changed the reference strategy, the call to SysDocument.SysFile will lazily load the SysFile.  If you've set the reference load strategy to DoNotLoad, which you did in an earlier post, then the SysFile won't be retrieved.   DevForce scalar navigation properties don't return null, they return a null entity if no entity exists.   More here - http://drc.ideablade.com/xwiki/bin/view/Documentation/null-entity.

 

Also remember that if you're working in Silverlight all lazy loads are asynchronous.  When called, these properties return a pending entity or pending entity list.