To be precise, Assume that the Parent node has 5 Sales orders (1,2,3,4,5). When a Sales order 1 is accessed the supply function method is triggered and corresponding details of sales order 1 are stored in the child node. When sales order 2 is triggered supply function method is triggered and the details of sales order 2 are stored in the child node. Now if we don’t have a singleton option in the node and if select the lead for sales order 1, this time the supply function method will not be triggered as the element is already available in the memory. The same if I have had the singled property selected, then when I accessed the 2nd sales order the memory allocated for the first sales order will be destroyed. Now if I choose the first sales order then once again supply function method gets triggered and loads the data, this time it clears the second element which is already available in the child node. This way it ensures that only one element available in the child node.

 

Supply Function: Supply function is a method assigned to the context node which is being executed every time the context node is being accessed. It is used for initializing or invalidating the context node.