Checks if a YAML header was specified and can be parsed. If not, generates a
feedback message. If yes, parses the YAML header and zooms in on its options
so you can use check_option to verify the options.
check_yaml(state, error_msg = NULL, append = TRUE)
| state | the state to start from. This state should be produced by
|
|---|---|
| error_msg | If specified, this overrides the automatically generated message in case the YAML header couldn't be parsed. |
| append | Whether or not to append the feedback to feedback built in previous states. |
A state that zooms in on the YAML header options.