fhir_next_bundle_url {fhircrackr}

Next Bundle's URL

Description

fhir_next_bundle_url() gives the link to the next available bundle, either of the bundle you provided in the argument bundle or of the last call to fhir_search(), if bundle=NULL (the default).

This function is useful when you don't have a lot of memory available or when a download of bundles was interrupted for some reason. In case of small memory, you can use fhir_next_bundle_url together with the max_bundle argument from fhir_search() to download bundles in smaller batches in a loop. See details in the example.

Usage

fhir_next_bundle_url(bundle = NULL)

Arguments

bundle

The bundle from which you wish to extract the next link. If this is NULL (the default), the function will extract the next link from the last bundle that was downloaded in the most recent call to fhir_search().

Value

A fhir_url object referencing next bundle available on the FHIR server. Empty fhir_url / character vector, if no further bundle is available.

Examples

#' #the try({}, silent = TRUE) statement is only there to catch errors when the server is down
#you can skip it when the server is reachable

try({


# workflow for small memory environments, downloading small batches of bundles
# for really small memory environments consider also using the `_count` option in
# your FHIR search request.
# You can iteratively download, crack and save the bundles until all bundles are processed or the
# desired number of bundles is reached.
url <- fhir_url("https://server.fire.ly/Patient")
count <- 0
obs <- fhir_table_description(resource = "Patient")
design <- fhir_design(obs)
while(length(url)>0 && count < 5){
	 bundles <- fhir_search(url, max_bundles = 2)
	 tables <- fhir_crack(bundles, design)
  save(tables, file = paste0(tempdir(),"/table_", count, ".RData"))
  count <- count + 1
  url <- fhir_next_bundle_url()
}
#you can see the saved tables here:
dir(tempdir())


}, silent = TRUE)