Extract shape file coordinates from a leaflet map in shiny app - r

Question

I have a shape file to plot on the map in shiny app. The file structure is as follow :
user#servr:~/home/shp$ ls -la
total 48
drwxr-xr-x 2 user user Jan 17 13:17 .
drwxr-xr-x 7 user user 4096 Jan 17 13:13 ..
-rw-r--r-- 1 user user 5 Jan 17 13:13 myshape.cpg
-rw-r--r-- 1 user user 423 Jan 17 13:13 myshape.dbf
-rw-r--r-- 1 user user 404 Jan 17 13:13 myshape.prj
-rw-r--r-- 1 user user 132 Jan 17 13:13 myshape.sbn
-rw-r--r-- 1 user user 116 Jan 17 13:13 myshape.sbx
-rw-r--r-- 1 user user 15044 Jan 17 13:13 myshape.shp
-rw-r--r-- 1 user user 108 Jan 17 13:13 myshape.shx
I could read those file in R as well :
myspdf <- readOGR(dsn = "/home/shp/",layer = "myshape")
myspdf <- spTransform(myspdf, CRS("+init=epsg:4326"))
Now the str of myspdf is :
Formal class 'SpatialPolygonsDataFrame' [package "sp"] with 5 slots
..# data :'data.frame': 1 obs. of 3 variables:
.. ..$ Shape_Leng: num 80111
.. ..$ Shape_Area: num 59127699
.. ..$ GISFILE : chr "O22_EVAR_ArchWreckFound_v01_221216dehm25833_Buff400m"
..# polygons :List of 1
.. ..$ :Formal class 'Polygons' [package "sp"] with 5 slots
.. .. .. ..# Polygons :List of 3
.. .. .. .. ..$ :Formal class 'Polygon' [package "sp"] with 5 slots
.. .. .. .. .. .. ..# labpt : num [1:2] 420838 6079834
.. .. .. .. .. .. ..# area : num 50391583
.. .. .. .. .. .. ..# hole : logi FALSE
.. .. .. .. .. .. ..# ringDir: int 1
.. .. .. .. .. .. ..# coords : num [1:586, 1:2] 429230 429217 429183 429148 429114 ...
.. .. .. .. ..$ :Formal class 'Polygon' [package "sp"] with 5 slots
.. .. .. .. .. .. ..# labpt : num [1:2] 424698 6072349
.. .. .. .. .. .. ..# area : num 6408830
.. .. .. .. .. .. ..# hole : logi FALSE
.. .. .. .. .. .. ..# ringDir: int 1
.. .. .. .. .. .. ..# coords : num [1:312, 1:2] 421726 421745 421765 421785 421806 ...
.. .. .. .. ..$ :Formal class 'Polygon' [package "sp"] with 5 slots
.. .. .. .. .. .. ..# labpt : num [1:2] 422217 6071588
.. .. .. .. .. .. ..# area : num 2329246
.. .. .. .. .. .. ..# hole : logi FALSE
.. .. .. .. .. .. ..# ringDir: int 1
.. .. .. .. .. .. ..# coords : num [1:32, 1:2] 425110 421328 420681 420682 420683 ...
.. .. .. ..# plotOrder: int [1:3] 1 2 3
.. .. .. ..# labpt : num [1:2] 420838 6079834
.. .. .. ..# ID : chr "0"
.. .. .. ..# area : num 59129659
.. .. .. ..$ comment: chr "0 0 0"
..# plotOrder : int 1
..# bbox : num [1:2, 1:2] 413125 6069810 430341 6084226
.. ..- attr(*, "dimnames")=List of 2
.. .. ..$ : chr [1:2] "x" "y"
.. .. ..$ : chr [1:2] "min" "max"
..# proj4string:Formal class 'CRS' [package "sp"] with 1 slot
.. .. ..# projargs: chr "+proj=utm +zone=33 +ellps=GRS80 +towgs84=0,0,0,0,0,0,0 +units=m +no_defs"
.. .. ..$ comment: chr "PROJCRS[\"ETRS89 / UTM zone 33N\",\n BASEGEOGCRS[\"ETRS89\",\n DATUM[\"European Terrestrial Reference"| __truncated__
..$ comment: chr "TRUE"
This shows that I have 3 separated area with coordinates array of length 586,312 and 32. I'm able to get the coordinate of the polygons as well :
coor01 <- myspdf#polygons[[1]]#Polygons[[1]]#coords
coor02 <- myspdf#polygons[[1]]#Polygons[[2]]#coords
coor03 <- myspdf#polygons[[1]]#Polygons[[3]]#coords
What I am looking for is the option on shiny app, which by click on the shape file I get the coordinate (coor01,coor02 or coor03) !
Right now if I click on shape file from the app, I get always one single lat and lng value not the complete list !
library(shiny)
library(leaflet)
library(rgdal)
ui <- fluidPage(
titlePanel(p("Spatial app", style = "color:#3474A7")),
sidebarLayout(
sidebarPanel(
),
mainPanel(
leafletOutput("map")
)
)
)
# server()
server <- function(input, output, session) {
data <- reactiveValues(clickedShape=NULL)
myspdf <- readOGR(dsn = "/home/shp/",layer = "myshape")
myspdf <- spTransform(myspdf, CRS("+init=epsg:4326"))
output$map<-renderLeaflet({
leaflet() %>% addTiles()%>% addPolygons(data = myspdf,highlight = highlightOptions(
weight = 5,
color = "#666",
dashArray = "",
fillOpacity = 0.7,
bringToFront = TRUE))
})
observeEvent(input$map_shape_click,{
print("observed map_marker_click")
data$clickedShape <- input$map_shape_click
print(data$clickedShape)
})