R/suntime.R

In UBC-MDS/climateR: API wrapper for weather data

#' suntime: Sunrise and sunset time of a particular city
#'
#' @import httr
#'
#' @import lubridate
#'
#' @import stringr
#'
#' @param city string value
#'
#' @return list of sunrise and sunset time in the given city
#'
#'
#' @export
#'
#' @examples
#' suntime("London")

suntime <- function(city){

  #Base query
  query_base <- "https://www.metaweather.com/api/"

  #Error handling
  if (!is.character(city)){
    stop("The city must be a string.")
  }
  if (length(content(GET(paste0(query_base,"location/search/?query=",city)))) == 0){
    stop("This city does not exist.")
  }

  #Retrieve where on earth id  and coordinates of city through API
  search_location <- content(GET(paste0(query_base, "location/search/?query=", city)))
  woeid <- search_location[[1]]$woeid


  search_values <- content(GET(paste0(query_base, "location/",woeid,"/")))

  sunrise <- ymd_hms(search_values$sun_rise)
  sunset <- ymd_hms(search_values$sun_set)

  sunrise_clean <- str_split(sunrise, " ")[[1]][2]
  sunset_clean <- str_split(sunset, " ")[[1]][2]

  sun_time <- paste0((hour(sunset) - hour(sunrise)), " hours and ", (minute(sunset) - minute(sunrise)), " minutes")

  return(list(sunrise = sunrise_clean, sunset = sunset_clean, day_time = sun_time))
}