带有标题的ggtitle在弹出传单R中

Question

我有一个闪亮的仪表板，可以在其中放置图形的标题，其中每个图形都属于特定的行。在这部分代码中，来自AIR的代码在ggplot部分而不是ggtitle部分被识别。知道解决方法的人吗？

output$plotFlights <- renderLeaflet({
df <- dataInputFlights()
leaflet() %>%
  addTiles() %>%  
  addPolylines(data = df, lng = ~long, lat = ~lat, group = ~group, weight = 2, color = "#000000",
               popup = popupGraph(ggplot(filter(leafletData, airline == df$airline, fromAirport == df$fromAirport, toAirport == df$toAirport, group == "A"), 
                                         aes(x = arr_delay)) + ggtitle(paste("van: ", fromAirport, " naar: ", toAirport)) + 
                                    geom_histogram(fill = "#000000") + geom_vline(aes(xintercept = mean(arr_delay, na.rm = TRUE)), color = "grey", linetype = "dashed", size = 1) + 
                                    xlab("Arrival delay")  + 
                                    thema + guides(fill = FALSE)))

I would like to add the title to this graph, but the title is line specific (there could be more lines)

数据框看起来像这样

id group lat long airline distance fromAirport toAirport datum flightnumber arr_delay dep_delay 1 1 A 40.63975 -73.77893 Endeavor Air Inc. 1029 John F Kennedy Intl Minneapolis St Paul Intl 2013-01-01 3538 11 0 2 1 B 44.88196 -93.22177 Endeavor Air Inc. 1029 John F Kennedy Intl Minneapolis St Paul Intl 2013-01-01 3538 11 0 3 2 A 40.63975 -73.77893 Endeavor Air Inc. 228 John F Kennedy Intl Washington Dulles Intl 2013-01-01 4105 -2 -9 4 2 B 38.94453 -77.45581 Endeavor Air Inc. 228 John F Kennedy Intl Washington Dulles Intl 2013-01-01 4105 -2 -9 5 3 A 40.63975 -73.77893 Endeavor Air Inc. 301 John F Kennedy Intl Buffalo Niagara Intl 2013-01-01 3295 -2 -3 6 3 B 42.94053 -78.73217 Endeavor Air Inc. 301 John F Kennedy Intl Buffalo Niagara Intl 2013-01-01 3295 -2 -3

如果您需要更多信息来帮助我，请问我，我会给你的！