Make template's tokens public

[stefanomondino]

In some cases it would be useful to analyze a template and report back all occurences of variables to do some client-side validation for provided context before actual render happens. example:

template string: hello my name is {{ name }} provided context: ["something": "someValue"]

In my scenario I can give feedback to users before rendering happens ("warning! name variable is missing from your context but is used in templates", something like that), but I don't know how to retrieve template's variables, since the tokens seems to be internal and not public.

[ilyapuchka]

Hm, why not to make this a configurable error if default behaviour to render nothing is not desirable? There is a good error support already in Stencil that shouldn't require any additional preprocessing on the client side.

[stefanomondino]

My point was to perform some kind of analysis on the template itself before it's actually rendered. Basically I'm developing a CLI that can display all needed variables with some kind of --help command, I can try to see if I can handle this with errors.

I've tried my own fork (with public tokens) in my use case and it works but doesn't handle well filters: {{ name | uppercase }} has a variable name of name | uppercase and not name as I expected, probably I'm missing some key concepts in the whole process :)