add new get_api_key function, address #105

DESCRIPTION

@@ -14,7 +14,8 @@ LazyData: true
 RoxygenNote: 7.3.1
 Imports:
     httr,
-    jsonlite
+    jsonlite,
+    rlang
 Suggests:
     knitr,
     rmarkdown

NAMESPACE

@@ -2,6 +2,7 @@
 
 export(getCensus)
 export(getFunction)
+export(get_api_key)
 export(listCensusApis)
 export(listCensusMetadata)
 export(makeVarlist)

NEWS.md

@@ -5,6 +5,8 @@
 ## New features
 * `getCensus()` no longer requires `key`, the use of a Census Bureau API key. Users are still encouraged to register for and use an API key because the Census Bureau may rate limit IP addresses, but it is not required. (#87)
 
+* New `get_api_key()` helper function retrieves the value of a user's stored Census Bureau API key from a saved environment variable or provides a warning message if none is found.
+
 * `listCensusApis()` now has optional `name` and `vintage` parameters to get metadata for a subset of datasets or a single dataset. (#103)
 
 ```R

R/getcensus_functions.R

@@ -258,13 +258,7 @@ getCensus <-
 
 	# Check for key in environment, print a message if one is not provided or in environment
 	if (is.null(key)) {
-		if (Sys.getenv("CENSUS_KEY") != "") {
-			key <- Sys.getenv("CENSUS_KEY")
-		} else if (Sys.getenv("CENSUS_API_KEY") != "") {
-			key <- Sys.getenv("CENSUS_API_KEY")
-		} else {
-			message("You are not using a Census API key. Using a key is recommended but not required.\nThe Census Bureau may limit your daily requests.\nYou can register for an API key at https://api.census.gov/data/key_signup.html\nLearn more at https://www.hrecht.com/censusapi/articles/getting-started.html.")
-		}
+		key <- get_api_key()
 	}
 	apiurl <- constructURL(name, vintage)
 

R/metadata_functions.R

@@ -131,12 +131,15 @@ listCensusApis <- function(name = NULL,
 #' @param name API programmatic name - e.g. acs/acs5. Use `listCensusApis()` to
 #'   see valid dataset names.
 #' @param vintage Vintage (year) of dataset. Not required for timeseries APIs.
-#' @param type Type of metadata to return. Options are: "variables" (default) -
-#'   list of variable names and descriptions for the dataset. "geographies" -
-#'   available geographies. "groups" - available variable groups. Only available
-#'   for some datasets. "values" - encoded value labels for a given variable.
-#'   Pair with "variable_name". This information is only available for some
-#'   datasets.
+#' @param type Type of metadata to return. Options are:
+#'
+#'   * "variables" (default) - list of variable names and descriptions
+#'   for the dataset.
+#'   * "geographies" - available geographies.
+#'   * "groups" - available variable groups. Only available
+#'   for some datasets.
+#'   * "values" - encoded value labels for a given variable. Pair with
+#'   "variable_name". Only available for some datasets.
 #' @param group An optional variable group code, used to return metadata for a
 #'   specific group of variables only. Variable groups are not used for all
 #'   APIs.

_pkgdown.yaml

@@ -39,6 +39,7 @@ reference:
   - makeVarlist
 - title: "Helpers"
   contents:
+  - get_api_key
   - fips
 
 redirects: