改变 R Leaflet 中的标签颜色

Question

我有一个带有二进制变量和 xy 坐标的数据框。我可以使用 Leaflet 映射数据并改变每个变量的标记颜色，但我想知道是否也可以改变标签颜色。

以下是数据示例。现在我只能将标签设置为一种颜色（例如黑色）。在此示例中，我希望电子产品的标签为蓝色字体，非电子产品的标签为红色字体。

library(leaflet)
library(mapview)

data <- data.frame("ID"=1:5, "Name" = c("ipod", "book", "phone", "ipod", "book"), "Color" = c("blue","red","blue","blue","red"), "Lat"=c(38.56250,38.66163,38.66574,38.55060,38.55060), "Long"=c(-90.59690,-90.5000,-90.37138,-90.35756,-90.5285))

pal<-(colorFactor(c("blue","red"), domain=c("blue", "red")))

map <-leaflet()  %>% addTiles() %>% 
  setView(lng = -90.576959, lat  = 38.440455, zoom = 10) %>% 
  addProviderTiles("Esri") %>%
  addCircleMarkers(data=data, lng = ~Long, lat= ~Lat, radius = 5, fillColor = ~pal(`Color`), color="black", fillOpacity = .90, weight = 1) %>%
  addLabelOnlyMarkers(
    data = data,
    label = as.character(data$Name),
    labelOptions = labelOptions(noHide = T, #hides labels
                                direction = "auto", 
                                textOnly = F, 
                                offset = c(0,0),
                                style = list(
                                  "color" = "black", 
                                  "font-family" = "serif",
                                  "font-style" = "normal",
                                  "box-shadow" = "1px 1px rgba(0,0,0,0.25)",
                                  "font-size" = "12px",
                                  "border-color" = "rgba(0,0,0,0.5)",
                                  "padding" = "2px" 
                                )))
map

Answer 1

您需要做一些解决方法，将标签替换为 HTML。

在

addLabelOnlyMarkers()

函数中，将

label =  as.character(data$Name)

替换为以下代码：

label = purrr::map(glue::glue("<span style='color:{data$Color}'>{as.character(data$Name)}<span>"),htmltools::HTML)

因此，您不再使用文本作为标签，而是使用 HTML 作为标签：

[[1]]
<span style='color:blue'>ipod<span>

[[2]]
<span style='color:red'>book<span>

[[3]]
<span style='color:blue'>phone<span>

[[4]]
<span style='color:blue'>ipod<span>

[[5]]
<span style='color:red'>book<span>