Leaf Expand Buttons with Lazy Child Loading
A relation-graph demo that shows how leaf nodes can display built-in expand buttons before they have children. Expanding those placeholders triggers a one-shot simulated async load, appends new nodes and lines with the graph instance API, and reruns tree layout so the new branch settles into place.
Lazy Child Loading from Leaf Expand Buttons
What This Example Builds
This example builds a full-height left-to-right tree that mixes one static branch with one highlighted lazy-loading branch. The canvas starts with a white b subtree that is already populated and a gold c subtree whose leaf placeholders c1, c2, and c3 already show expand buttons even though they do not have children yet.
Users can click the built-in expand button on those placeholder leaves, see a Loading...