在闪亮的应用程序中缓存或预渲染传单地图

使用Flatgeobuf格式: 基于 leafem :: addFgb :的描述 Flatgeobuf可以逐块传输数据，以便呈现地图或多或少是瞬时的.地图是响应式的，而数据是仍在加载，以便弹出查询，缩放和平移将起作用即使尚未渲染所有数据.我认为数据集是线串，这就是为什么 fillColor 似乎被忽略的原因. 库(传单)图书馆(leafem)图书馆(闪亮)#通过URL(大约13mb的数据)url ="https://raw.githubusercontent.com/bjornharrtell/flatgeobuf/3.0.1/test/data/UScounties.fgb"ui<-fluidPage(leafletOutput("mymap"，宽度="700px"，高度="700px"))服务器<-功能(输入，输出，会话){output $ mymap<-renderLeaflet({传单()％>％addTiles()％&％;％leafem ::: addFgb(url = url，组=县"，标签=名称"，弹出窗口= TRUE，fillColor =蓝色"，fillOpacity = 0.6，颜色=黑色"，重量= 1)％>％addLayersControl(overlayGroups = c("counties"))％&％setView(lng = -105.644，lat = 51.618，zoom = 3)})}ShinyApp(用户界面，服务器) 使用 leafgl (WebGL-Renderer): 库(sf)图书馆(闪亮)图书馆(传单)图书馆(leafgl)plz<-st_read("C:/用户/用户/下载/plz-gebiete.shp"，layer＝plz-gebiete")ui<-fluidPage(leafletOutput("mymap"，宽度="700px"，高度="700px"))服务器<-功能(输入，输出，会话){output $ mymap<-renderLeaflet({传单()％>％addTiles()％&％;％addGlPolygons(data = plz，color =〜plz，popup ="note"，group ="plz")％>％addLayersControl(overlayGroups ="plz")})}ShinyApp(用户界面，服务器) I am trying to map ~8000 polygons using leaflet and run into performance issues.As I am using the map within a shiny app, I was wondering if its possible to somehow cache or pre-render the map.Note that in my case, I have different layers of polygons that are swapped following this approach.A small MWE would be this:The data can be downloaded from herelibrary(shiny)library(leaflet)library(sf)## Download Shapefilefile <- "plz-gebiete.shp"if (!file.exists(file)) { url <- "https://www.suche-postleitzahl.org/download_files/public/plz-gebiete.shp.zip" zipfile <- paste0(file, ".zip") download.file(url, zipfile) unzip(zipfile)}df <- st_read(file, options = "ENCODING=UTF-8")# If possible: pre-render the map here!library(shiny)ui <- fluidPage( leafletOutput("mymap", width = "700px", height = "700px"))server <- function(input, output, session) { output$mymap <- renderLeaflet({ leaflet() %>% addTiles() %>% addPolygons(data = df, weight = 1, color = "black") })}shinyApp(ui, server)It takes around 16 seconds on my machine to render the map with the polygons.If possible, I would like to pre-render the map once, save it as an .rds file, and load it on demand. Note that I know the width/height of the map within the app (here set to 700px). But something likemap <- renderLeaflet({leaflet() %>% ...})saveRDS(map, "renderedmap.rds")map <- readRDS("renderedmap.rds")# within server()output$mymap <- mapdoes not result in any performance gains.Alternatively, I have tried to load the leaflet asynchronously so that other parts of the app can be rendered/interacted with but to no avail.Any ideas how to solve or circumnavigate this problem? 解决方案 The 2 following approaches dont exactly answer your question, but they are definitly more performant alternatives compared to leaflet::addPolygons.Using Flatgeobuf Format:Based on the description from leafem::addFgb:Flatgeobuf can stream the data chunk by chunk so that rendering of themap is more or less instantaneous. The map is responsive while data isstill loading so that popup queries, zooming and panning will workeven though not all data has been rendered yet.I think the dataset are linestrings, that is why fillColor seems to be ignored.library(leaflet)library(leafem)library(shiny)# via URL (data around 13mb)url = "https://raw.githubusercontent.com/bjornharrtell/flatgeobuf/3.0.1/test/data/UScounties.fgb"ui <- fluidPage( leafletOutput("mymap", width = "700px", height = "700px"))server <- function(input, output, session) { output$mymap <- renderLeaflet({ leaflet() %>% addTiles() %>% leafem:::addFgb( url = url, group = "counties", label = "NAME", popup = TRUE, fillColor = "blue", fillOpacity = 0.6, color = "black", weight = 1) %>% addLayersControl(overlayGroups = c("counties")) %>% setView(lng = -105.644, lat = 51.618, zoom = 3) })}shinyApp(ui, server)Using leafgl (WebGL-Renderer):library(sf)library(shiny)library(leaflet)library(leafgl)plz <- st_read("C:/Users/user/Downloads/plz-gebiete.shp", layer = "plz-gebiete")ui <- fluidPage( leafletOutput("mymap", width = "700px", height = "700px"))server <- function(input, output, session) { output$mymap <- renderLeaflet({ leaflet() %>% addTiles() %>% addGlPolygons(data = plz, color = ~plz, popup = "note", group = "plz") %>% addLayersControl(overlayGroups = "plz") })}shinyApp(ui, server) 这篇关于在闪亮的应用程序中缓存或预渲染传单地图的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持！ 上岸，阿里云！