Template Select should allow run-time options

[spuder]

Component name

Select

Link to component documentation on our website

https://esphome.io/components/select/template.html

Describe the enhancement

Currently all options in the template select must be defined at compile time.
The component should allow updating values at run time (without needing a 3rd party api like home assistant).

Use cases

esp32 fetches a list of printers from a rest api using http_request.get.
I want to select the correct mqtt topic to subscribe to based on the result of the select box

Anything else?

No response

[spuder]

Here is an example with a modification to the template sensor that shows what I'm looking for.
The printer list is updated dynamically from a rest call.

external_components:
- source:
    type: git
    url: https://github.com/spuder/esphome
    ref: template_select_options
  components: [ template ]
  refresh: 0s

Working code here: esphome/esphome@dev...spuder:esphome:template_select_options

cons

While this works, it currently requires a browser refresh to populate the values in the drop down box.

[jesserockz]

The problem with this is that the options are only sent to HA once per connection. They cannot be updated
To allow something like this, we need to add new logic to the api and HA to allow updating an entities info anytime after connection. THis would be a bigger change than simply updating the list inside the select and requires it's own feature-request and discussion/decisions before it is tackled.