Making Custom Properties aware of their context in EPiServer

What you might want to do inside a custom property is to check the value of some other properties in the current page. What you will notice is that Custom Properties are not aware of the CurrentPage, in order to fetch it you will need to override the
InitializeData method that the base class of all EPiServer properties has.

You can get the pagereference within that method

PageReference _pageLink;

public override void InitializeData(EPiServer.ApplicationConfiguration config,PropertyDataCollection properties)
{
PropertyPageReference pageLinkProperty = properties["PageLink"] as PropertyPageReference;
if (!pageLinkProperty.IsNull) { _pageLink = pageLinkProperty.PageLink;}
base.InitializeData(config, properties);
}