I’m trying to implemenent a Vaadin Grid Tree in a Polymer Project but not getting the desired behavior. Although I’ve followed the demo example and the data is rendered as it should be, the expanded behavior is not the expected, duplicating the entries, and not expanding/collapsing the correct items (see attached images).
Hello. So you are apparently using items property, which currently does not support tree structure. Only dataProvider is supported, please note that the [demo]
(https://cdn.vaadin.com/vaadin-grid/4.1.8/demo/#grid-tree-demos) is explicitly called “Assigning Tree Data Using Data Provider”.
Please follow the [issue]
(https://github.com/vaadin/vaadin-grid/issues/1142) to track the Tree support with the "items" property. We are not going to ship it in the upcoming v5.0.0, but that is likely to be fixed in one of the subsequent minor releases.