use piamInterfaces to generate mappings

[orichters]

Purpose of this PR

• refactor xlsx_IIASA.R, called via output.R -> export
• if no mapping file is provided, generate one using piamInterfaces
• improves the use of iiasatemplate such that also units are checked and possibly corrected
• write more to the log file about what has been done
• @pfuehrlich-pik: do I have to add piamInterfaces elsewhere to the dependencies? I added a line to the renv tutorial as well that I found useful
• requires add checkIIASASubmission pik-piam/piamInterfaces#14

Type of change

(Make sure to delete from the Type-of-change list the items not relevant to your PR)

• Refactoring
• no impact on default scenarios

Checklist:

• My code follows the coding etiquette
• I have performed a self-review of my own code

[pfuehrlich-pik]

There's also sink which can achieve a similar thing: Run sink(LOGFILE, append = TRUE, type = "message", split = TRUE), then all calls to message will write to terminal (actually stderr) and the logfile. You must remember to call sink() at the end of the script/when you want to stop redirecting output to the logfile.

[orichters]

split = TRUE only splits R output (via Rvprintf) and the default output from writeLines: it does not split all output that might be sent to stdout. (https://stat.ethz.ch/R-manual/R-devel/library/base/html/sink.html)

So I don't think it works here…

[pfuehrlich-pik]

Could be, although in my experience sink usually works as expected. I'm a little afraid that we will see meslog or similar functions defined over and over in different scripts, in that case I'd much prefer pulling meslog up into e.g. the gms package.

[orichters]

please try sink(file("test.log", "w"), type = "message", split = TRUE) (without the file part, it also crashes):

Error in `sink()`:
! cannot split the message connection

Happy to add meslog or something similar to gms.

[pfuehrlich-pik]

Okay I'm convinced sink does not like messages. I just remembered another way:

withCallingHandlers({
  # all the code that should message to console and log
}, message = function(x) {
  cat(x$message, file = LOGFILE, append = TRUE)
  message(x$message) # not sure, maybe need to use cat here
})

This is better than the sink approach anyway, because you cannot forget to run sink() at the end. This is also similar to what madrat does.

[pfuehrlich-pik]

This is the right way to declare the dependency, yes.

[pfuehrlich-pik]

Will this also still print to console or only to logFile?

[orichters]

it prints also to console. I don't know exactly, why, to be fair, but what you suggested produced two prints to the console.

[pfuehrlich-pik]

Okay good. I'd guess there's a chain of handlers, and after your custom handler it will just continue with the default handler which prints to console.