add get_layer_estimates()

NAMESPACE

@@ -18,6 +18,7 @@ export(create_feature_server)
 export(delete_features)
 export(get_all_layers)
 export(get_layer)
+export(get_layer_estimates)
 export(get_layers)
 export(list_fields)
 export(list_items)

NEWS.md

@@ -1,5 +1,6 @@
 # arcgislayers 0.1.0 (unreleased)
 
+- Add `get_layer_estimates()` to retrieve estimate info such as the number of features and the extent of the layer
 - Add `truncate_layer()` to support truncate and append workflow
 - Add support for opening `MapServers` <https://github.com/R-ArcGIS/arcgislayers/pull/83>
 - `arc_open()` with a layer that does not support `Query` sets the `n` attribute to`NA` <https://github.com/R-ArcGIS/arcgislayers/pull/83>

R/get-estimates.R

@@ -0,0 +1,69 @@
+#' Get Estimates
+#'
+#' @inheritParams arc_select
+#'
+#' @references [ArcGIS REST Doc](https://developers.arcgis.com/rest/services-reference/enterprise/get-estimates-feature-service-layer-.htm)
+#' @examples
+#' furl <- "https://services.arcgis.com/P3ePLMYs2RVChkJx/ArcGIS/rest/services/USA_Counties_Generalized_Boundaries/FeatureServer/0"
+#'
+#' county_fl <- arc_open(furl)
+#' get_layer_estimates(county_fl)
+#' @export
+#' @returns
+#' A named list containing all estimate info. If `extent` is present,
+#' it is available as an object of class `bbox`.
+get_layer_estimates <- function(x, token = Sys.getenv("ARCGIS_TOKEN")) {
+
+ # check if its a supported layer
+ obj_check_layer(x)
+
+ # check if `infoInEstimates` is null
+ if (is.null(x[["infoInEstimates"]])) {
+ cli::cli_abort(
+ "{.var {rlang::caller_arg(x)}} does not have estimates."
+ )
+ }
+
+ b_req <- httr2::request(x[["url"]])
+
+
+ est_req <- httr2::req_url_path_append(
+ b_req,
+ "getEstimates"
+ )
+
+ # token bug :[
+ if (token != "") {
+ resp <-
+ httr2::req_url_query(est_req, f = "json") |>
+ httr2::req_auth_bearer_token(token) |>
+ httr2::req_perform()
+ } else {
+ resp <-
+ httr2::req_url_query(est_req, f = "json") |>
+ httr2::req_perform()
+ }
+
+ # process json string
+ res_raw <- httr2::resp_body_string(resp) |>
+ RcppSimdJson::fparse()
+
+ # process extent if present
+ ext <- res_raw[["extent"]]
+
+ if (!is.null(ext)) {
+ crs <- sf::st_crs(ext[["spatialReference"]][[1]])
+ bbox <- sf::st_bbox(
+ unlist(ext[c("xmin", "ymin", "xmax", "ymax")]),
+ crs = crs
+ )
+ res_raw[["extent"]] <- bbox
+ }
+
+ # return the rest
+ res_raw
+}
+
+
+
+