`SelectableTreeView`: Unable to load multiple instances on one page

[JeremyCaney]

In a previous commit, I introduced a new OnTopic.SelectableTreeView wrapper around the Ext.Tree control (2b644b9). The goal of this was to simplify the configuration of trees by centralizing common configuration values used by OnTopic.

Unfortunately, in doing so, this appears to have introduced a bug when there are multiple Relationship attributes on a content type. In this case, the tree from the first relationship is rendered for the second relationship, and a tree is not rendered for the first relationship. As a result, not only might this display the wrong tree, but it also won't render the correct selected items.

Positively, the backing field continues to operate correctly. As such, existing values won't be overwritten when submitting updates. Further, new values set in the rendered tree will be persisted. Negatively, there is no way to remove existing values, nor to make any updates to the relationship without a rendered tree.

It's unclear what's going on here. Presumably, the trees are not being properly namespaced.

[JeremyCaney]

This was due to the root configuration being defined in the global OnTopic.SelectableTreeView.defaults object. This created a new Ext.tree.AsyncTreeNode instance, but as that was shared between all instances of SelectableTreeView, it interfered with data binding. Moving this into the constructor solves the issue.