R/queries.R

In rOpenSpain/senadoRES: Information About the Senate of Spain

#' Retrieve the XML content
#'
#' Look up on the internet and get the content
#' @param query A character with the url of the query to the website.
#' @param encoding A character with the encoding, usually either "windows-1252", "ISO-8859-15" or "UTF-8".
#' @importFrom httr content
#' @importFrom httr GET
#' @importFrom httr user_agent
#' @importFrom httr status_code
#' @importFrom httr http_type
#' @keywords internal
get_xml <- function(query, encoding) {
    user_agent <- user_agent("https://github.com/llrs/senadoRES")
    response <- GET(query, user_agent)

    if (response$url != query) {
        stop(domain = NA,
             gettext("Resource likely moved. Contact the maintainer and explain what you tried.",
                                domain="R-senadoRES"), call. = FALSE)
    }
    if (status_code(response) != 200) {
        stop("Could not retrieve the data.", call. = FALSE)
    }
    if (http_type(response) == "text/html") {
        warning("Missing data.", call. = FALSE)
    }
    if (http_type(response) != "text/xml") {
        stop("API did not find the requested document.", call. = FALSE)
    }


    if (missing(encoding)) {
        encoding <- "ISO-8859-15"
    }
    # Encoding found via the browser
    # BOCG_B_14_110.XML has windows-1252
    # BOCG_B_14_27.XML has windows-1252 but uses utf8
    # BOCG_T_14_3.XML has ISO-8859-15
    # BOCG_T_14_110.XML has ISO-8859-15
    # Apparently ISO-8859-15 includes the windows-1252
    # Other areas like https://www.senado.es/web/ficopendataservlet?tipoFich=7&legis=14 has UTF-8
    out <- content(response, encoding = encoding)
    if (is.null(out)) {
        stop("The response is empty", call. = FALSE)
    }
    out
}


compose_url <- function(url, ...) {
    if (missing(url)) {
        url <- "https://www.senado.es/web/ficopendataservlet?"
    }
    l <- list(...)
    other <- unlist(l, recursive = FALSE)
    names_arg <- paste0(names(other), "=")
    paste0(url, paste0(names_arg, other, collapse = "&"))
}