Query (list_layers.R)

[rellimylime]

list_layers.R is the query function. It turns STAC item metadata into a clean table that users can filter before retrieval.

list_layers() loads all STAC items, extracts the key fields (id, domain, layer_type, data_type, is_hosted, href), applies optional filters for each of these categories, and returns a data frame.

It also includes load_stac_items() as a helper to read item JSON from extdata and fail early if the catalog path is missing or empty.

• list_layers()
  

  fedex/R/list_layers.R

  Lines 1 to 87 in f191448

  	#' List available WRI layers
  	#'
  	#' Query the STAC catalog to find available layers. Filter by domain,
  	#' layer type, data type, or hosting status.
  	#'
  	#' @param domain Character. Filter by WRI domain ("air_quality", "communities",
  	#' "infrastructure", "livelihoods", "sense_of_place", "species", "habitats",
  	#' "water", or "unknown" for overall WRI score). Default NULL (all domains).
  	#' @param layer_type Character. Filter by layer type ("resistance", "resilience",
  	#' "recovery", "status", "domain_score"). Default NULL (all types).
  	#' @param data_type Character. Filter by data type ("indicator", "aggregate",
  	#' "final_score"). Default NULL (all types).
  	#' @param hosted_only Logical. If TRUE, return only layers hosted on KNB.
  	#' Default FALSE.
  	#'
  	#' @returns A data.frame with columns: id, domain, layer_type, data_type, is_hosted, href
  	#' @export
  	#'
  	#' @examples
  	#' # See all available layers
  	#' list_layers()
  	#'
  	#' # Find all air quality layers
  	#' list_layers(domain = "air_quality")
  	#'
  	#' # Find all resistance indicators
  	#' list_layers(layer_type = "resistance", data_type = "indicator")
  	#'
  	#' # Find what's currently hosted on KNB
  	#' list_layers(hosted_only = TRUE)
  	#'
  	#' # Filter by multiple criteria
  	#' list_layers(domain = "communities", layer_type = "resistance")
  	list_layers <- function(domain = NULL,
  	layer_type = NULL,
  	data_type = NULL,
  	hosted_only = FALSE) {
  	# Load all STAC items
  	items <- load_stac_items()
  	# Extract metadata into a data.frame
  	layer_info <- lapply(items, function(item) {
  	props <- item$properties
  	href <- item$assets$data$href
  	# Check if hosted by examining the href
  	# If it starts with http:// or https://, it's hosted
  	is_hosted <- grepl("^https?://", href)
  	data.frame(
  	id = item$id,
  	domain = if (is.null(props$wri_domain)) NA_character_ else props$wri_domain,
  	layer_type = if (is.null(props$wri_layer_type)) NA_character_ else props$wri_layer_type,
  	data_type = if (is.null(props$data_type)) NA_character_ else props$data_type,
  	is_hosted = is_hosted,
  	href = href,
  	stringsAsFactors = FALSE
  	)
  	})
  	# Combine into single data.frame
  	df <- dplyr::bind_rows(layer_info)
  	# Apply filters
  	if (!is.null(domain)) {
  	df <- df[df$domain == domain & !is.na(df$domain), ]
  	}
  	if (!is.null(layer_type)) {
  	df <- df[df$layer_type == layer_type & !is.na(df$layer_type), ]
  	}
  	if (!is.null(data_type)) {
  	df <- df[df$data_type == data_type & !is.na(df$data_type), ]
  	}
  	if (hosted_only) {
  	df <- df[df$is_hosted, ]
  	}
  	# Reset row names
  	rownames(df) <- NULL
  	# Return sorted by id
  	df[order(df$id), ]
  	}

• load_stac_items()
  

  fedex/R/list_layers.R

  Lines 90 to 114 in f191448

  	# Helper function to load all STAC items
  	load_stac_items <- function() {
  	# Define stac directory
  	stac_dir <- system.file("extdata/stac/collections/wri_ignitR/items",
  	package = "fedex")
  	# Check that it exists
  	if (!dir.exists(stac_dir)) {
  	stop("STAC catalog not found. Package may not be installed correctly.")
  	}
  	# Extract list of stac item files
  	item_files <- list.files(stac_dir, pattern = "\\.json$", full.names = TRUE)
  	# Check that there are items in the catalog
  	if (length(item_files) == 0) {
  	stop("No items in STAC catalog.")
  	}
  	# Read all items
  	items <- lapply(item_files, jsonlite::read_json, simplifyVector = TRUE)
  	items
  	}

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