Dear all,
I'd like your advice on handling errors conditionally within a function.
Imagine a function that does several database operations. The user has the
option to run them inside a transaction. So the code has somewhere near the
top:
if (transaction) {
DBI::dbBegin(conn)
}
At the end of the function there is a command which commits the transaction.
if (transaction) {
DBI::dbCommit(conn)
}
If something goes wrong, one reverses the database operations by issuing
the DBI::dbRollback(conn) command. The first option for issuing that is to
use tryCatch(). The drawback is that the set of command can be a few
hundred lines, which harms readability when wrapping them into a tryCatch().
tryCatch(
{potentially long set of commands},
error = function(e){
if (transaction) {
dbRollback(conn)
}
stop(e)
}
)
Another options I've found is to set options(error = function(){}) I assume
that this has a permanent effect on the current R session? So I should
reset that as a part of the error handling?
What would be recommended: tryCatch() or options(error = ...)? Or are there
more / better solutions?
Best regards,
ir. Thierry Onkelinx
Instituut voor natuur- en bosonderzoek / Research Institute for Nature and
Forest
team Biometrie & Kwaliteitszorg / team Biometrics & Quality Assurance
Kliniekstraat 25
1070 Anderlecht
Belgium
To call in the statistician after the experiment is done may be no more
than asking him to perform a post-mortem examination: he may be able to say
what the experiment died of. ~ Sir Ronald Aylmer Fisher
The plural of anecdote is not data. ~ Roger Brinner
The combination of some data and an aching desire for an answer does not
ensure that a reasonable answer can be extracted from a given body of data.
~ John Tukey
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