Thanks for the try, Ondina.
My scenario is different from what you've described. First of all the messages are retrieved not based on authorId. The collection of messages returned contains messages from different authors. Moreover, they are retrieved from a different server than list of contacts (authors). At any point in time a status of one of the authors may change and then as a result the collection of messages will have to be re-rendered to show the correct status icon for that author. But regardless of how these two collections are retrieved, only the messages collection is assigned as a data provider for the List component. The list component is using ItemRenderer for rendering each message in the list. So ItemRenderer has to access the authors list (proxy) to find the status and name of the author. My question is how to access proxies from the ItemRenderer?