Is a simple card that expands a group to a list of entities to be used with entities, glance, etc. Some people still wanted to reuse their automation groups to show them on the UI without redoing things.
Keep in mind that you can use this with any cards that take as parameter entities array (like glance, entitites, etc.).
Is there some way to get this to work with the light card?
I get the following: 2018-12-07 10:22:33 ERROR (MainThread) [frontend.js.latest.201812050] https://REDACTED/frontend_latest/4a0b71976892b9590a9c.chunk.js:4818:651 Uncaught Error: Specify an entity from within the light domain.
Hi
I this cards works fine with single groups, but I can’t get it work with a group with groups inside.
For example, every room is a group, additional I have a group for every floor. Also my house is a group with all floor groups inside.
I want to configurate a entity-filter for every floor and for the whole house, so that I can see if a window or a switch is on/open.
If I configurate it like this, lovelace crash.
Use individual entities for your floor/whole house groups, not groups ex: "first floor: (entity 1)(entity 2) etc…
much harder but it will work that way.
Sorry, i don’t get it.
The Thing is, that a group for example is a room with entities inside.
Many rooms are a floor, so the floor group is a group of room groups.
Many floors are a house, so the house group is a group of floor groups.
In the end I just need to Change the entities of a room and the floors and house is updated.
Your not a programmer, aren’t you?
Because this is the first lesson a programmer learns, if part of a code is entered multiple times, then put it in a method.
Even in the official docs of home assistant (Groups) the first thing you see are groups inside a group.
Why would they explain it that way, when you should not use it?
I dunno… it’s a storm in a teacup… I still have a couple of groups so for instance I can group some automations together to enable/disable as a group bu they are decoupling the front-end display from the back-end. How many times do you plan on adding an entity to lovelace? It’s almost 95% or the time do it once done forever… Or cut and paste…
Right now, I work with the group card. So I normally don’t add any entity to lovelance (except cameras or valves).
That’s the great thing with this card!
In the last couple of weeks, some smart plugs, sensors, cameras, arrived and I had to add new entitys all the time.
But as said, I add them to groups and lovelance is updated automatically.
For example I have a card with all rooms of a floor, and I have a card for every room.
I use have the group card for switches in the floor and in the room.
When I add a switch, I only have to add it to the group and both cards are updated.
Totally simple!
to me the nice thing about this it lets me put the same group multiple places without having to duplicate the entries. For example think of a header with time/date at the top of each page. I can put the entities in a group and then just put the group on each page. Adding new things, like /outside temp/outside weather (sunny, cloudy, rainy, etc) is as simple as adding them to the group then they show up on every page. Also, I have an upstairs bathroom, I also have views setup for every bedroom upstairs. I have the bathroom duplicated on each room view. It would be nice if that were a group that could be included on each page. Saves on the typing.
I particularly like combining this with the Entity Filter card, for example to view all people that are home without having to put everyone of them in the configuration.
type: 'custom:group-card'
card:
type: entity-filter
state_filter:
- home
card:
type: glance
title: Devices at home
group: group.all_devices
Keep in mind that you can use this with any cards that take as parameter 
if you like the cards so much that wish to express your gratitude.
