Merge pull request #2 from andypicke/1-add-option-to-specify-entity-i…

…n-data-request

add option to specify entity in get_electricity_generation

DESCRIPTION

@@ -13,4 +13,5 @@ URL: https://github.com/andypicke/emberr
 BugReports: https://github.com/andypicke/emberr/issues
 Imports: 
     httr,
-    jsonlite
+    jsonlite,
+    stringr

R/get_electricity_generation.R

@@ -1,22 +1,32 @@
 #' Get Ember electricity-generation data from API
 #' @param temporal_resolution "yearly" (default) or "monthly"
-#' @param min_date default=2015
-#' @param max_date default=2023
+#' @param min_date Mininum date to retrieve data for. YYYY or YYYY-MM format. Default=2015
+#' @param max_date Maximum date to retrieve data for. YYYY or YYYY-MM format. Default=2023
+#' @param entity List of comma-separated country(s) or region(s) to return data for. Default is all (no filter)
 #' @param api_key Default is Sys.getenv("EMBER_API_KEY")
 #' @returns df Dataframe of requested data
 #' @export
 
 get_electricity_generation <- function(temporal_resolution = "yearly",
                                        min_date = "2015",
                                        max_date = "2023",
+                                       entity = "all",
                                        api_key = Sys.getenv("EMBER_API_KEY")) {
 
   base_url <- "https://api.ember-climate.org/v1/"
 
   endpoint <- "electricity-generation/"
 
+  if (entity == "all") {
+    entity_str <- ""
+  } else {
+    entity_str <- paste0("entity=", stringr::str_replace(entity, " ", "%20"), "&") # '%20' replaces space in URL
+  }
+
   query_url <- paste0(base_url, endpoint, temporal_resolution, "?",
+                      entity_str,
                       "start_date=", min_date, "&end_date=", max_date,
+                      entity_str,
                       "&api_key=", api_key)
 
   df <- get_api_request(query_url)