Re-reads every CS9_DBCONFIG_* environment variable and rebuilds the four
configuration tables.
Details
cs9 reads the environment once, in its own .onLoad(). A package that sets
its own CS9_DBCONFIG_* values inside .onLoad() therefore sets them too
late: cs9 is a dependency, so it loads first and has already read the
environment by the time the dependent package runs. Call this function
immediately after the Sys.setenv() block and cs9 picks the new values up.
It re-runs set_env_vars(), which rebuilds config$dbconfigs, and then
setup_database_tables(), which rebuilds config$tables. Neither opens a
database connection: csdb::DBTable_v9 creates its table lazily, on first
use.
State safety
The reload is safe against both a failed reload and a repeated one.
It disconnects every table it is about to discard, so a second reload does not leak the connections held by the R6 objects it replaces.
It then empties config$tables before it touches config$dbconfigs. A
failure anywhere after that point therefore leaves config$tables empty
rather than holding tables built from the previous configuration. An empty
table list is an honest "not configured"; a stale one describes a database
that config$dbconfigs no longer points at.
See also
check_environment_setup(), which reports whether the environment
is complete.
The installation vignette, vignette("installation", package = "cs9").
Examples
if (FALSE) { # \dontrun{
# In a dependent package's .onLoad(), before its own setup runs
Sys.setenv(CS9_DBCONFIG_ACCESS = "config/anon")
Sys.setenv(CS9_DBCONFIG_DRIVER = "SQLite")
Sys.setenv(CS9_DBCONFIG_DB_CONFIG = "/tmp/config.sqlite")
Sys.setenv(CS9_DBCONFIG_DB_ANON = "/tmp/anon.sqlite")
cs9::reload_db_config()
} # }