Lazy Loading Tree Results In Unnecessary Network Activity

[acabler]

Using the tree dijit with a ForestStoreModel and a JsonRestStore, there is a lot of unnecessary network activity. On every expansion, the root is queried once again for every node. From reading the docs, this is not supposed to happen since the goal of lazy loading is efficiency.

[bill]

Not sure which docs you were reading but the ForestStoreModel API doc, in the "event summary" section, explains that:

onSetItem(item, attribute, oldValue, newValue) Updates the tree view according to changes to an item in the data store. Developers should override this method to be more efficient based on their app/data.

Actually, many of the methods in ForestStoreModel need to be overridden, as documented in that documentation section.

Sorry that this is kind of confusing, but anyway it will become easier with #13781.

[bill]

test file to reproduce problem, modified from original Tree_with_JRS.html to not automatically open the tree nodes