api_class.R

#' Api class to make appropriate request based on parameters
#'
#' @field api_type character. The name of the api to call (see url_mapping)
#' @field export_format character (default = "JSON"). The export's format
#' Available are CSV, XLSX, SDMX-ML and JSON
#' @field parameters character. Additional request parameters
#' @field id character. The identifier or id of the request's object
#' @field language character (default = "en"). The language of the response data.
#' Available are 'fr', 'de', 'it', 'en'
#' @field version_format numeric (default = 2.1). The export format's version
#' (2.0 or 2.1 when format is SDMX-ML) 
#' (for 'codelist')
#' @field api_url character. The url to make the request to.
#' 
#' @importFrom methods new
api_class <- setRefClass(
  "Api",
  fields = list(
    api_type = "character",
    export_format = "character",
    parameters = "character",
    id = "character",
    language = "character",
    version_format = "numeric",
    api_url = "character"
  ),
  methods = list(
    initialize = function(...,
                          export_format = "JSON",
                          parameters = "",
                          id = "",
                          language = "en",
                          version_format = 2.1) {
      callSuper(
        ...,
        export_format = export_format,
        parameters = parameters,
        id = id,
        language = language,
        version_format = version_format,
      )
      get_url(id, export_format, version_format, language)
    },
    get_response = function() {
      request_function <- REQUEST_FUNCTION_MAPPING[[export_format]]
      if (parameters == "") {
        url <- glue::glue("{BASE_URL}/api/{api_url}")
      } else {
        url <- glue::glue("{BASE_URL}/api/{api_url}?{parameters}")
      }
      request_function(url)
    },
    get_url = function(id, export_format, version_format, language) {
      url_mapping <- hash::hash(
        "codelist" =
          glue::glue("CodeLists/{id}/exports/{export_format}/{version_format}"),
        "dcat_data_structure" =
          glue::glue("DataStructures/{id}/{language}"),
        "nomenclature_one_level" =
          glue::glue("Nomenclatures/{id}/levelexport/CSV"),
        "nomenclature_multiple_levels" =
          glue::glue("Nomenclatures/{id}/multiplelevels/CSV"),
      )
      api_url <<- url_mapping[[api_type]]
    }
  )
)