I was wondering if it is possible to link the item state of a an equipment item in the model to the state of a child item. For example, I have an equipment item “Garage Door”. This equipment contains different controls for opening and closing it, as well as the garage door state item. The state of Garage Door is per default “null” because the opening state of the garage door is stored in a child item linked to the respective channel.
I am now wondering, whether I can show the open state, i.e. “Open”, “Closed” as the state label of the parent item without manually writing rules for that.
There are actually two different ideas here. The first, can you set a group item to the state of one of it’s member items, is mostly no. A group can only have a state when it has an aggregation function. All the available aggregation functions calculate a group state in the basis of all the members items. The answer to this question is then “mostly no” because the only way to use an aggregation function to get the value of one member item is if that item is the only member of the group.
The second idea is: can you display the value of one member of a group when viewing that group, and the answer is absolutely. When the UI is showing you an item, group or otherwise, it is using either the default standalone widget for that item or the default list widget for that item. The Getting Started tutorial takes you through an example of how to create and configure default widgets like that, so you could just set the default widgets for this equipment group to a widget which displays that item states you are interested in.