R/visualizePolygons.R

In PredictiveEcology/SpaDES.shiny: Utilities for building 'shiny' apps for 'SpaDES' simulations

#' Visualize \code{SpatialPolygons*} (shiny module)
#'
#' Display a \code{SpatialPolygons*} objects on a leaflet map.
#'
#' @template id
#'
#' @param ... Additional parameters passed to \code{link[leaflet]{leafletOutput}}.
#'
#' @return None. Invoked for the side-effect of generating UI for a leaflet map.
#'
#' @export
#' @importFrom shiny NS
#' @importFrom leaflet leafletOutput
#' @rdname visualizePolygons
visualizePolygonsUI <- function(id, ...) {
  ns <- NS(id)

  leafletOutput(ns("map"), ...)
}

#' @template input
#' @template output
#' @template session
#' @param poly      Reactive value with polygon to visualize.
#' @param proxy     Proxy to a leaflet map on which polygons should be displayed.
#'                  See \code{\link[leaflet]{leafletProxy}}
#'
#' @return None. Invoked for the side-effect of rendering leaflet map.
#'
#' @export
#' @importFrom shiny renderPlot is.reactive
#' @importFrom leaflet leaflet addTiles addPolygons
#' @rdname visualizePolygons
visualizePolygons <- function(input, output, session, poly, proxy = NULL) {
  if (is.null(proxy)) {
    output$map <- renderLeaflet({
      leaflet() %>%
        addTiles() %>%
        addPolygons(data = poly(), group = session$ns("group")) ## don't change ns
    })

    proxy <- leafletProxy("map")
    callModule(polygonsUpdater, "updater", proxy, poly, group = session$ns("group")) ## don't change ns #nolint
  } else {
    callModule(polygonsUpdater, "updater", proxy, poly)
  }
}