robotoolbox keeps form metadata and languages in memory for the rest of the
R session, so that kobo_data(), kobo_lang_set() and kobo_lang_get() do
not rebuild them on every call.
Details
A form and its languages are cached under the server URL, the asset uid and the form version. Without an explicit version, the version is the deployed one, or the draft for a form that was never deployed. A redeployed form has a new version, so the next call builds and caches the new form. The same uid on two servers gives two cache entries.
kobo_data() also records, per server URL, the number of submissions the
server returns per request when it is lower than the number asked, and uses
it for the following requests.
The cache is cleared when the R session ends, or with
kobo_cache_clear().