Templates in the data: block of Dev->Services aren't casted/converted to the expected type

[rccoleman]

The problem

Templates in the data: block of Dev->Services aren't casted/coerced into the expected field type, but they are in a script. This example from the input_datetime docs works in a script, but not in Dev->Services:

- service: input_datetime.set_datetime
  data:
    entity_id: input_datetime.XXX
    timestamp: "{{ now().timestamp() }}"

In Dev->Services, it results in the following error:

voluptuous.error.MultipleInvalid: expected float for dictionary value @ data['timestamp']

Templates always return strings, but it looks like they're converted to the expected type in a script, but not in the developer tools.

Environment

• Home Assistant Core release with the issue: 0.115.2
• Last working Home Assistant Core release (if known): Unknown
• Operating environment (OS/Container/Supervised/Core): OS
• Integration causing this issue: input_datetime
• Link to integration documentation on our website: https://www.home-assistant.io/integrations/input_datetime/

Problem-relevant configuration.yaml

I created an input_datetime (helper) in the UI for testing, and used this script:

  test:
    sequence:
      - service: input_datetime.set_datetime
        data:
          entity_id: input_datetime.date_test
          timestamp: "{{ now().timestamp() }}"

That works, while putting the following in the data section of Dev->Services with input_datetime.set_datetime results in the error mentioned:

entity_id: input_datetime.date_test
timestamp: "{{ now().timestamp() }}"

Traceback/Error logs

2020-09-20 08:59:17 ERROR (MainThread) [homeassistant.components.websocket_api.http.connection.140399136576464] expected float for dictionary value @ data['timestamp']
Traceback (most recent call last):
  File "/usr/src/homeassistant/homeassistant/components/websocket_api/commands.py", line 137, in handle_call_service
    await hass.services.async_call(
  File "/usr/src/homeassistant/homeassistant/core.py", line 1269, in async_call
    processed_data = handler.schema(service_data)
  File "/usr/local/lib/python3.8/site-packages/voluptuous/validators.py", line 208, in __call__
    return self._exec((Schema(val) for val in self.validators), v)
  File "/usr/local/lib/python3.8/site-packages/voluptuous/validators.py", line 287, in _exec
    raise e if self.msg is None else AllInvalid(self.msg, path=path)
  File "/usr/local/lib/python3.8/site-packages/voluptuous/validators.py", line 283, in _exec
    v = func(v)
  File "/usr/local/lib/python3.8/site-packages/voluptuous/schema_builder.py", line 272, in __call__
    return self._compiled([], data)
  File "/usr/local/lib/python3.8/site-packages/voluptuous/schema_builder.py", line 817, in validate_callable
    return schema(data)
  File "/usr/local/lib/python3.8/site-packages/voluptuous/schema_builder.py", line 272, in __call__
    return self._compiled([], data)
  File "/usr/local/lib/python3.8/site-packages/voluptuous/schema_builder.py", line 594, in validate_dict
    return base_validate(path, iteritems(data), out)
  File "/usr/local/lib/python3.8/site-packages/voluptuous/schema_builder.py", line 432, in validate_mapping
    raise er.MultipleInvalid(errors)
voluptuous.error.MultipleInvalid: expected float for dictionary value @ data['timestamp']

This may actually be a "frontend" issue, so feel free to move if necessary.

Additional information

[probot-home-assistant[bot]]

Hey there @home-assistant/core, mind taking a look at this issue as its been labeled with an integration (input_datetime) you are listed as a codeowner for? Thanks!
_{^{(message by CodeOwnersMention)}}

[rccoleman]

In fairness, this is probably a frontend or template engine issue and not directly related to the datetime integration. I'd move it if I could.

[rccoleman]

This is still an issue with 0.116, and another user saw the issue templates feeding into the rgb_color for a light. I'd fix or add a more appropriate label if I could because this seems like a general issue with Dev->Services.

Tinkerer pointed out that 0.117 will return native types and may address this and hopefully that will unify the behavior of scripts & the dev tools.

[balloob]

The service dev tool does not render templates.

[rccoleman]

And yet, it does, just with this quirk :)

[rccoleman]

This still doesn't work properly in 0.117, despite the change to have templates return native data types. I created an input_number helper and attempted to set the value using Dev->Services like this:

The service data is this:

entity_id: input_number.test
value: "{{ states('input_number.test')|float + 10.0 }}"

And the error is this:

voluptuous.error.MultipleInvalid: expected float for dictionary value @ data['value']

It seems like we're in a sort of middle ground where templates are evaluated in dev tools, but types aren't being handled properly. I see people running across this regularly in Discord, and it makes it difficult to support them when the behavior in DevTools doesn't reflect what will happen in a script/automation. Here's the latest example:

https://discord.com/channels/330944238910963714/672223497736421388/769651662541291530

[balloob]

Nah, it's not a middle ground. Dev tools do not support templates. Persistent notification and notify do support templates in their own service handling.

[bramkragten]

Should we move this to the frontend as a feature request?

[balloob]

Would you expect the frontend to process the data and then call the service? Or would you expect the websocket API call service command to get a flag to "render templates"?

I kinda like the idea of putting it in the frontend, because we could show the user what the values are that we passed to the service. Transferring.