使传单层可点击或不可点击，无需重新排序

Question

在SO或Google中找不到答案，然后我自己成功地找到了解决方案，我决定同时提出问题和答案。

可重复的代码可以在下面的“答案”中找到。

问题

默认情况下，所有层都是“可点击的”。因此，当使用多个层时，特别是在覆盖另一个层(例如标记和多边形)时，您的层的顺序决定了什么是可点击的。标记与多边形覆盖将保持不可点击，即使没有标签弹出是伴随多边形。

我发现关于这个问题的唯一一篇文章是：Leaflet Map - second Polygon makes the first layer unclickable

天真的解决方案是确保标记是最后分层的。不幸的是，如果您使用像addLayersControl()这样的函数，启用/禁用一个层会将该层移动到前面。因此，虽然层顺序最初很重要，但它并不能真正“解决”这个问题。

Answer 1

解决方案

相应地使用函数pathOptions()、markerOptions()和labelOptions()。

在我的例子中，是多边形层导致了这个问题。通过执行addPolygons(..., options = pathOptions(clickable = FALSE))，这些都是“不可点击的”。

示例

library(rgdal) # for spatial data
library(leaflet)
library(dplyr)
library(magrittr)

# download and load state border data
url <- "http://www2.census.gov/geo/tiger/GENZ2015/shp/cb_2015_us_state_5m.zip"
temp <- tempfile(fileext = '.zip')
download.file(url, temp)
unzip(temp, exdir = dirname(temp))
states <- rgdal::readOGR(file.path(dirname(temp), "cb_2015_us_state_5m.shp"),
  layer = "cb_2015_us_state_5m", verbose = FALSE)
unlink(temp)

# code adopted from https://rstudio.github.io/leaflet/shapes.html
neStates <- subset(states, states$STUSPS %in% c(
  "CT","ME","MA","NH","RI","VT","NY","NJ","PA"
))

cities <- read.csv(textConnection("
City,Lat,Long,Pop
Boston,42.3601,-71.0589,645966
Hartford,41.7627,-72.6743,125017
New York City,40.7127,-74.0059,8406000
Philadelphia,39.9500,-75.1667,1553000
Pittsburgh,40.4397,-79.9764,305841
Providence,41.8236,-71.4222,177994
"))


# (1) polygon layer added last; cannot click cities/circles
map_1 <- leaflet(neStates) %>%
  addProviderTiles("CartoDB.Positron") %>%
  addCircles(data = cities, lng = ~Long, lat = ~Lat, weight = 1,
    radius = ~sqrt(Pop) * 30, popup = ~City,
    group = "Cities") %>%
  addPolygons(
    stroke = FALSE, fillOpacity = 0.2, smoothFactor = 0.5,
    color = ~colorQuantile("YlOrRd", states$AWATER)(AWATER),
    group = "States") %>%
  addLayersControl(overlayGroups = c('Cities', 'States'),
    options = layersControlOptions(collapsed = FALSE))


# (2) polygon layer made 'unclickable' (clickable = FALSE)
map_2 <- leaflet(neStates) %>%
  addProviderTiles("CartoDB.Positron") %>%
  addCircles(data = cities, lng = ~Long, lat = ~Lat, weight = 1,
    radius = ~sqrt(Pop) * 30, popup = ~City,
    group = "Cities") %>%
  addPolygons(
    stroke = FALSE, fillOpacity = 0.2, smoothFactor = 0.5,
    color = ~colorQuantile("YlOrRd", states$AWATER)(AWATER),
    group = "States",
    options = pathOptions(clickable = FALSE)) %>% # DISABLE 'clickable'
  addLayersControl(overlayGroups = c('Cities', 'States'),
    options = layersControlOptions(collapsed = FALSE))


map_1 # even if polygon layer is put last, disable/enable layer puts it in front again
map_2 # disable/enabling any layer has no impact!