add memoising for layer info

NAMESPACE

@@ -13,5 +13,6 @@ export(layer_attributes_get_names)
 export(layer_attributes_summarise)
 export(layer_attributes_tbl)
 importFrom(magrittr,"%>%")
+importFrom(memoise,memoise)
 importFrom(rlang,.data)
 importFrom(rlang,`%||%`)

NEWS.md

@@ -1,5 +1,8 @@
 # EMODnetWFS (development version)
 
+* Added memoising (caching during each R session) of the functions getting services
+ and layers information (#52).
+
 # EMODnetWFS 2.0.1
 
 * Introduced better handling of server response errors.

R/info.R

@@ -1,21 +1,43 @@
-#' Get WFS available layer information
-#'
-#' @param wfs A `WFSClient` R6 object with methods for interfacing an OGC Web Feature Service.
-#' @inheritParams emodnet_init_wfs_client
-#' @importFrom rlang .data `%||%`
-#' @return a tibble containg metadata on each layer available from the service.
+.emodnet_get_layer_info <- function(wfs, layers) {
+
+    check_wfs(wfs)
+
+    layers <- namespace_layer_names(wfs, layers)
+
+    capabilities <- wfs$getCapabilities()
+
+    wfs_layers <- purrr::map(layers, capabilities$findFeatureTypeByName) %>%
+        unlist(recursive = FALSE)
+
+    tibble::tibble(
+        data_source = "emodnet_wfs",
+        service_name = wfs$getUrl(),
+        service_url = get_service_name(wfs$getUrl()),
+        layer_name = purrr::map_chr(wfs_layers, ~.x$getName()),
+        title = purrr::map_chr(wfs_layers, ~.x$getTitle()),
+        abstract = purrr::map_chr(wfs_layers, ~getAbstractNull(.x)),
+        class = purrr::map_chr(wfs_layers, ~.x$getClassName()),
+        format = "sf"
+    ) %>%
+        tidyr::separate(
+            .data$layer_name,
+            into = c("layer_namespace", "layer_name"),
+            sep = ":"
+        ) %>%
+        unique()
+}
+
+#' @describeIn emodnet_get_wfs_info Get metadata for specific layers. Requires a
+#' `wfs` object as input.
+#' @inheritParams emodnet_get_layers
+#' @importFrom memoise memoise
+#' @details To minimize the number of requests sent to webservices,
+#' these functions use `memoise` to cache results inside the active R session.
+#' To clear the cache, re-start R or run `memoise::forget(emodnet_get_wfs_info)`/`memoise::forget(emodnet_get_layer_info)`.
 #' @export
-#' @describeIn emodnet_get_wfs_info Get info on all layers from am EMODnet WFS service.
-#' @examples
-#' emodnet_get_wfs_info(service = "bathymetry")
-#' # Query a wfs object
-#' wfs_cml <- emodnet_init_wfs_client("chemistry_marine_litter")
-#' emodnet_get_wfs_info(wfs_cml)
-#' # Get info for specific layers from wfs object
-#' layers <- c("bl_fishing_monitoring",
-#'            "bl_beacheslocations_monitoring")
-#' emodnet_get_layer_info(wfs = wfs_cml, layers = layers)
-emodnet_get_wfs_info <- function(wfs = NULL, service = NULL, service_version = "2.0.0") {
+emodnet_get_layer_info <- memoise::memoise(.emodnet_get_layer_info)
+
+.emodnet_get_wfs_info <- function(wfs = NULL, service = NULL, service_version = "2.0.0") {
 
     if(is.null(wfs) & is.null(service)){
         usethis::ui_stop("Please provide a valid {usethis::ui_field('service')} name or {usethis::ui_field('wfs')} object.
@@ -42,39 +64,24 @@ emodnet_get_wfs_info <- function(wfs = NULL, service = NULL, service_version = "
                         sep = ":")
 
 }
-
-#' @describeIn emodnet_get_wfs_info Get metadata for specific layers. Requires a
-#' `wfs` object as input.
-#' @inheritParams emodnet_get_layers
+#' Get WFS available layer information
+#'
+#' @param wfs A `WFSClient` R6 object with methods for interfacing an OGC Web Feature Service.
+#' @inheritParams emodnet_init_wfs_client
+#' @importFrom rlang .data `%||%`
+#' @return a tibble containg metadata on each layer available from the service.
 #' @export
-emodnet_get_layer_info <- function(wfs, layers) {
-
-    check_wfs(wfs)
-
-    layers <- namespace_layer_names(wfs, layers)
-
-    capabilities <- wfs$getCapabilities()
-
-    wfs_layers <- purrr::map(layers, capabilities$findFeatureTypeByName) %>%
-        unlist(recursive = FALSE)
-
-    tibble::tibble(
-        data_source = "emodnet_wfs",
-        service_name = wfs$getUrl(),
-        service_url = get_service_name(wfs$getUrl()),
-        layer_name = purrr::map_chr(wfs_layers, ~.x$getName()),
-        title = purrr::map_chr(wfs_layers, ~.x$getTitle()),
-        abstract = purrr::map_chr(wfs_layers, ~getAbstractNull(.x)),
-        class = purrr::map_chr(wfs_layers, ~.x$getClassName()),
-        format = "sf"
-    ) %>%
-        tidyr::separate(
-            .data$layer_name,
-            into = c("layer_namespace", "layer_name"),
-            sep = ":"
-        ) %>%
-        unique()
-}
+#' @describeIn emodnet_get_wfs_info Get info on all layers from am EMODnet WFS service.
+#' @examples
+#' emodnet_get_wfs_info(service = "bathymetry")
+#' # Query a wfs object
+#' wfs_cml <- emodnet_init_wfs_client("chemistry_marine_litter")
+#' emodnet_get_wfs_info(wfs_cml)
+#' # Get info for specific layers from wfs object
+#' layers <- c("bl_fishing_monitoring",
+#'            "bl_beacheslocations_monitoring")
+#' emodnet_get_layer_info(wfs = wfs_cml, layers = layers)
+emodnet_get_wfs_info <- memoise::memoise(.emodnet_get_wfs_info)
 
 #' @describeIn emodnet_get_wfs_info Get metadata on all layers and all available
 #' services from server.