Cache responses from the STATcube REST API

Functions to cache requested resources in the directory ~/.STATcubeR_cache and reuse them in calls to sc_table(), sc_table_custom() sc_schema() and so forth. These functions are designed for testing and documentation and should not be regarded as part of the STATcubeR interface. The caching logic is likely to change in the future in which case sc_cache_clear() is required to purge old cache entries.

Usage

sc_cache_enable(verbose = TRUE)

sc_cache_disable()

sc_cache_enabled()

sc_cache_dir(dir = NULL)

sc_cache_files(x)

sc_cache_clear()

Arguments

verbose: print instructions on how to set up caching persistently via environment variables?
dir: a cache directory
x: an object of class sc_table or sc_schema

Value

for sc_cache_enable(), sc_cache_dir(): the path to the cache-directory
for sc_cache_disable(): TRUE
for sc_cache_enabled(): TRUE if caching is enabled, FALSE otherwise
for sc_cache_files(): the content of the cache associated with a file
for sc_cache_clear(): NULL

Details

Caching can be set up using environment variables. To set up a persistent cache for both Open Data and the REST API, the following lines in .Renviron can be used. The paths in this example are only applicable for UNIX-based operating systems.

STATCUBE_KEY_EXT   = YOUR_API_KEY_GOES_HERE
STATCUBE_CACHE     = TRUE
OD_CACHE_DIR       = "~/.cache/STATcubeR/open_data/"
STATCUBE_CACHE_DIR = "~/.cache/STATcubeR/api/"

If caching is enabled, there is no check to verify if the resources are unchanged in the server. Caching is not implemented for the endpoints sc_info() and sc_rate_limit_table().

Functions

sc_cache_enable(): enables caching for the current R session
sc_cache_disable(): disables caching for the current R session sc_cache_disable()
sc_cache_enabled(): informs whether the cache is currently enabled
sc_cache_dir(): get/set the directory used for caching
sc_cache_files(): get the cache file associated with an object
sc_cache_clear(): removes all files from the cache