R/resolve_read.R

In rDataPipeline: Functions to Interact with the 'FAIR Data Pipeline'

#' resolve_read
#' 
#' @keywords internal
#'
#' @param handle an object of class \code{fdp, R6} containing metadata required
#' by the Data Pipeline API
#' @param data_product a \code{string} specifying the name of the data product
#' @param component a \code{string} specifying the name of data product
#' component
#'
resolve_read <- function(handle, data_product, component = NA) {

  endpoint <- handle$yaml$run_metadata$local_data_registry_url
  read <- handle$yaml$read

  # If names(read) is not null, then a single entry has been added that
  # is not in a list, so put it in a list
  if (!all(is.null(names(read))))
    read <- list(read)

  # Find data product in `read:` section of config.yaml
  index <- lapply(read, function(x) x$data_product == data_product) %>%
    unlist() %>%
    which()

  if (length(index) == 0)
    usethis::ui_stop(paste(usethis::ui_field(data_product),
                           "not found in config file"))

  if (length(index) > 1)
    usethis::ui_stop("Multiple entries found in config file")

  this_read <- read[[index]]

  # Get aliases
  alias <- this_read$use

  # Get data product name
  if (any(names(alias) == "data_product")) {
    data_product <- this_read$use$data_product
  } else {
    data_product <- this_read$data_product
  }

  # Get component
  if (any(names(alias) == "component")) {
    component <- alias$component
  } else {
    component <- component
  }

  # Get version number
  if (any(names(alias) == "version")) {
    version <- this_read$use$version
  } else {
    version <- this_read$version
  }

  # Get namespace
  if (any(names(alias) == "namespace")) {
    namespace <- alias$namespace
  } else {
    namespace <- handle$yaml$run_metadata$default_input_namespace
  }

  namespace_id <- get_id("namespace", list(name = namespace))

  if (is.null(namespace_id))
    usethis::ui_stop(paste("default_input_namespace",
                           usethis::ui_field(namespace),
                           "not present in data registry"))

  assertthat::assert_that(length(namespace_id) == 1)

  # Get data product
  this_entry <- get_entry("data_product",
                          list(name = data_product,
                               version = version,
                               namespace = namespace_id),
                          endpoint = endpoint)

  if (is.null(this_entry))
    usethis::ui_stop(paste0(usethis::ui_field(namespace), ":",
                            usethis::ui_field(data_product), "@v.",
                            usethis::ui_field(version), " ",
                            "missing from data registry"))

  # Get data product path
  assertthat::assert_that(length(this_entry) == 1)
  this_object <- get_entity(this_entry[[1]]$object)
  this_object_id <- extract_id(this_object$url, endpoint = endpoint)
  this_location <- get_entity(this_object$storage_location)
  this_path <- this_location$path
  this_root <- get_entity(this_location$storage_root)$root

  if (grepl("^file://", this_root))
    this_root <- gsub("^file://", "", this_root)

  # Get object component URL
  if (is.na(component)) {
    component_url <- get_url("object_component",
                             list(object = this_object_id,
                                  whole_object = TRUE),
                             endpoint = endpoint)
  } else {
    component_url <- get_url("object_component",
                             list(object = this_object_id,
                                  name = component),
                             endpoint = endpoint)
  }

  assertthat::assert_that(length(component_url) == 1)

  list(data_product = data_product,
       component = component,
       component_url = component_url,
       version = version,
       namespace = namespace,
       path = paste0(this_root, this_path))
}