Jinja2 - How to get |list "value" for function?

Configuration Frontend
1

Hi,

With unavailable-entities-sensor I can get all unavailable entities.
Now I would like to filter them “up” to devices.
So with

{{ state_attr('sensor.unavailable_entities','entity_id')|map('device_id')|unique|list }}

I can get the list of device IDs.
But how can I translate the device IDs to device names? My approach is

{{ state_attr('sensor.unavailable_entities','entity_id')|map('device_id')|unique|list|map(device_attr(??????,'name'))|list }}

But what is the “keyword” for the piped list value in Jinja?

Thanks in advance!!!

2

device_attr() accepts entity ID’s, so you can leave out that conversion:

{{ state_attr('sensor.unavailable_entities','entity_id') 
| map('device_attr', 'name') | unique | list }}
1 Like
3

map("device_attr","name") should do the job, so

{ state_attr('sensor.unavailable_entities','entity_id')|map('device_id')|unique|list|map("device_attr","name")|list }}

For other available device attributes, see What attributes do devices have?

list | map(f,arg]) generates a list by applying the function with the name f to every element of its input. It takes an element from the list as the first argument for f and the second from arg, so it generates [f(list[0],arg),f(list[1],arg),...]

Edit: Skipping the device_id altogether as suggested by @Didgeridrew is even better of course, but that’s how it would work to map to name form device id

4

Thank you for your answer!
That is the solution for my specific case. But just for interest and learning: Is there a kind of “value” keyword for piped lists/maps in Jinja?
I’m coming from Java/C#/Javascript, so honestly Jinja sometimes is kinda weird or at least unnecessary complex for me. But I guess it’s a philosophy thing.

Edit: I got the point that map('device_id') is calling the function device_id and passing the value entity_id(list results) as argument. Calling functions via String argument is definitely not part of my C-like philosophy. :sweat_smile:

5

No, the elements of the list in a | map(...) filter are the (first) argument to the function. map() applies a function to every element of a list:

Assume a function

add(a,b):
  return a+b

then you can do

[1,2,3] | map ('add',5) | list`

which turns into

[add(1,5),add(2,5),add(3,5)]

so, ultimately

[6,7,8]

(Functional programming is a weird thing to get the head wrapped around. :exploding_head:)

1 Like