Issue with `SitecoreParentMapper` and caching

Hi,

I have a problem with Glass mapper caching. I try to describe the issue as good as possible. Given is the following base model:

public interface IBaseItem
{
    ...

    [SitecoreParent(IsLazy = true, InferType = true)]
    IBaseItem Parent { get; set; }

    ...
}

Where there are several content types which can be loaded into Parent (due to infertype). All of them have [SitecoreType(Cachable = true)]. To build my 3-level main navigation, I call the following code for each item:

protected bool IsAncestorOfItem(IBaseItem potentialAncestor, IBaseItem item)
{
    while (item != null)
    {
        if (item.ItemId == potentialAncestor.ItemId)
        {
            return true;
        }

        item = item.Parent;
    }

    return false;
}

With enabled Glass cache (new SitecoreContext { CacheEnabled = true };) this results in the following error:

Exception: System.NullReferenceException
Message: Object reference not set to an instance of an object.
Source: Glass.Mapper
   at Glass.Mapper.AbstractService.RunConfigurationPipeline(AbstractTypeCreationContext abstractTypeCreationContext)
   at Glass.Mapper.AbstractService.InstantiateObject(AbstractTypeCreationContext abstractTypeCreationContext)
   at Glass.Mapper.Sc.SitecoreService.CreateType(Type type, Item item, Boolean isLazy, Boolean inferType, Dictionary`2 parameters, Object[] constructorParameters)
   at Glass.Mapper.Sc.DataMappers.SitecoreParentMapper.MapToProperty(AbstractDataMappingContext mappingContext)
   at Glass.Mapper.Pipelines.ObjectConstruction.Tasks.CreateInterface.InterfacePropertyInterceptor.LoadValue(AbstractPropertyConfiguration propertyConfiguration)
   at Glass.Mapper.Pipelines.ObjectConstruction.Tasks.CreateInterface.InterfacePropertyInterceptor.Intercept(IInvocation invocation)
   at Castle.DynamicProxy.AbstractInvocation.Proceed()
   at Castle.Proxies.IOverviewPageProxy.get_Parent()
   at Feature.Navigation.Services.MainNavigationService.IsAncestorOfItem(IBaseItem potentialAncestor, IBaseItem item)
   .........

The error won’t be thrown for all items. Usually the first item called after an app pool recycle works, all other calls doesn’t work. If I disable Glass cache (new SitecoreContext { CacheEnabled = false };) I have no issues at all.

[mikeedwards83]

Hi @rootix I am working on an implementation at the moment that means if the requested model is set to be cachable then lazy loading is disabled. This will remove the need to mark every property as lazy=false and I hope resolve the issue you have described.

[kevinbrechbuehl]

Ehm no 😉 I just completely the property, didn’t see that true is the default value. And yes, of course both of you are right, when setting this explicitely to false then it works perfectly.

So the key message here is: Do not use lazy loading in properties when using Glass cache. Is there a way to globally disable lazy loading (also if this was set on a property)? Could this be disabled somewhere within the SitecoreService if cache is enabled?

Thanks for helping me out!