Signal information about a choice mizer made

Raises the condition that with_info_level() collects. This is the way for mizer, and for anything extending it, to tell the user about a default it filled in, an input it adjusted or an instruction it could not carry out, without deciding on its own how loudly to say it: the handler installed by whichever function the user actually called does that.

Usage

signal_info(
  var,
  message,
  level = 3,
  severity = c("info", "warning"),
  unhandled = c("drop", "show"),
  class = character()
)

Arguments

var: A string naming the quantity the report is about.
message: The message to give the user.
level: How important the report is. Level 1 is important enough to survive info_level = 1, level 3 is chatter that only the default info_level = 3 shows.
severity: "info" to report as a message, "warning" to report as a warning. Use "warning" when the user asked for something that is not happening, because a message can be, and on the species_params<-() path is, suppressed.
unhandled: What to do when no handler is collecting, for example because a rate setter was called directly rather than through setParams(). "drop" says nothing, which suits chatter that only makes sense as part of a report about a whole model. "show" reports it there and then, at the same severity: a message for "info" and a warning for "warning".
class: Further classes to give the condition, for code that wants to catch a particular kind of report.

Value

NULL invisibly. Called for its side effect of signalling.

Details

Progress reports are the one thing that does not belong here: they have to appear while the work is going on, and these are collected and given at the end.

Examples

# With nothing collecting, a `"drop"` report says nothing at all ...
signal_info("h", "Using a default for `h`.")

# ... whereas `unhandled = "show"` reports it there and then.
signal_info("h", "Using a default for `h`.", unhandled = "show")
#> Using a default for `h`.

# Normally it is raised inside a call whose body is wrapped in
# `with_info_level()`, which is what decides whether to show it.
with_info_level(signal_info("h", "Using a default for `h`."))
#> Using a default for `h`.