Feature Request: customizable behaviour on unknown value #110
Description
Currently if a variable does not exist, Chevron just replaces it with an unknown value:
# This will render 'hello '
result = chevron.render('{{ value1 }} {{ value2 }}', { 'value1': 'hello' })Is it possible to customize this? There's two main cases that would be useful:
- Raise an error on an unknown field; this helps us fail-fast when the result is due to a misspelling.
- Ignore the template directive, just render the text as is. So in the example above, leave it as
'hello {{ value2 }}'.
The first is useful in general; the second is useful for multi-pass rendering where we receive data at different stages, and want to render a partially-evaluated version of the template.