More bug fixes, improvements, and features

[PaulSD]

Primary changes:

• Use strict mode in eval() to keep the global javascript variable namespace clean.
• Allow ${} syntax in variables
• Allow disabling template parsing per value using a $! prefix
• Add support for "static" variables that are evaluated once when the card is loaded, rather than on every update
• Add support for templates that return Promises / use asynchronous functions. (Based on Allow async evaluation in special mode #149, with some changes/improvements.)

After this is merged, my opinion is that the dev branch is good enough to be merged into master.
However, of course, feel free to leave this in dev for now and do another beta release if you aren't comfortable with merging into master yet.

Closes #149.

[ildar170975]

Seems to be very massive work.
Separate thanks for "Upload Artifacts".
Will test.

Meanwhile, some FRs (could be implemented separately if possible):

1. Is it possible to add a config variable (stands for a config of a card) as available in templates?
2. Is it possible to make this scenario

variables:
  xxx: !secret my_super_secret

supported?

[PaulSD]

Is it possible to add a config variable (stands for a config of a card) as available in templates?

You mean you want the full original config of CTC (before evaluation of templates) available as a variable? Yeah, I can probably do that. Do you have an example of how you might use that, so I can make sure I implement this in a way that supports what you are trying to do?

!secret my_super_secret

Unfortunately this one isn't easy. !secret is processed by the YAML parser on the HA server, and I think it is only processed when parsing configuration.yaml (not when parsing any other YAML) ... If it isn't already being processed by HA before handing the config off to CTC, then I think the only way to handle this would be to modify HA itself to do that. (There is nothing CTC can do using the current HA APIs to handle that.)

[ildar170975]

You mean you want the full original config of CTC (before evaluation of templates) available as a variable? Yeah, I can probably do that. Do you have an example of how you might use that, so I can make sure I implement this in a way that supports what you are trying to do?

Thanks in advance! I decided to create a separate FR (#160) to avoid cluttering of this PR.

!secret is processed by the YAML parser on the HA server, and I think it is only processed when parsing configuration.yaml (not when parsing any other YAML)

Sad... We can use secrets in lovelace yaml like:

type: history-graph
hours_to_show: !secret xxxxxx

so I thought may be it could be possible to use them inside variables.

Thanks again!
Will keep testing these changes.