Variable {editUri} is a performance optimization hack: The ActiveTree template is called recursive for each node and then creates an "edit" link in each. This is expensive with many nodes. With client side expand/collapse, we always render the entire tree in fluid, with a bigger tree we're easily creating the link thousands of times. The hack below creates the link once, the usage then adds the child parameter. Ugly but effective in this case. Don't do this at home, kids.