Slowly accumulating map of Wellington buses (rate-limited to 1 route per 40sec)

wellybus.R

library(tidyverse)
library(leaflet)
library(jsonlite)
library(ratelimitr)
library(htmlwidgets)
library(htmltools)

allroutes<-read_csv("~/Downloads/WLG-google-transit/routes.txt") %>% filter(route_type==3)

download_route<-limit_rate(
	function(route) fromJSON(paste0("https://www.metlink.org.nz/api/v1/ServiceLocation/",route)),
	rate(n=1,period=20) )
	
	
makeItReload<-function(htmlfile){
    contents<-readLines(htmlfile)
    writeLines(gsub("</body>","<script type=\"text/javascript\"> setTimeout(function() { window.location.reload();}, 90*1000);</script></body>",contents, fixed=TRUE), htmlfile) 
}


allpos<-vector("list",nrow(allroutes))
names(allpos)<-allroutes$route_short_name

repeat({
for(route in allroutes$route_short_name){
    cat(route," ")
    
    if ((length(allpos[[route]])!=0) && (allpos[[route]]$h < as.POSIXlt(Sys.time())$hour-2))
        allpos[[route]]<-list()
    this_route<-tryCatch(download_route(route), error=function(e) NULL)
    if (is.null(this_route)) next
    if (!length(this_route$Services)) next
    if (NROW(this_route$Services)==0) next
        
    df<-this_route$Services %>% 
     select(Lat,Long, DelaySeconds, RecordedAtTime) %>% 
     separate(RecordedAtTime, into=c("y","mth","d","h","m","s","tz","tz2"),sep="[-:T+]") %>%
     mutate(lateness=case_when(DelaySeconds< -180 ~"magenta", 
     	DelaySeconds>= -180 & DelaySeconds<300~ "forestgreen", 
     	DelaySeconds>=300 & DelaySeconds<600~"orange",
     	DelaySeconds>=600~"red")) %>%
     mutate(popup=paste0(route,paste("<br/>",abs(round(DelaySeconds/60)),"mins", ifelse(DelaySeconds<0,"early", "late"),"at",h,":",m)))

    allpos[[route]]<-df
    m <- leaflet(bind_rows(allpos)) %>% 
    	addProviderTiles("CartoDB.Positron") %>% 
    	addCircleMarkers(~as.numeric(Long),~as.numeric(Lat),col=~lateness,popup=~popup) %>%
        addLegend("bottomright",title=paste("Wellington buses (past hour or so)"),
                  colors=c("magenta","forestgreen","orange","red"),labels=c("Early", "On schedule","5-10 min late","10+ min late"))
    	
   saveWidget(widget=m,"/Volumes/tlum005/buses/wellybus.html",selfcontained=FALSE)
   tryCatch(
        makeItReload("/Volumes/tlum005/buses/wellybus.html"),
        error=function(e) {cat("Didn't reload\n")}
        )
}
})