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 cs9 loads first. cs9 reads the
environment before the dependent package runs. Call this function
immediately after the Sys.setenv() block. cs9 then 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()
} # }