How to Properly Store ShapeFiles when Deploying R Shiny App

Question

I am working on an R Shiny project to visualize the spread of COVID19 around the world. When I run the app locally, it works just fine, but when I try to deploy the app, it runs into issues which I am assuming are related to storing the shapefiles: I get an error on the map page that reads, "An error has occurred. Check your logs or contact the app author for clarification."

Here is my code so far:

#Read in datasets
who_data <- read.csv("https://covid19.who.int/WHO-COVID-19-global-data.csv")
pops <- read.csv("https://gist.githubusercontent.com/curran/0ac4077c7fc6390f5dd33bf5c06cb5ff/raw/605c54080c7a93a417a3cea93fd52e7550e76500/UN_Population_2019.csv")


#download.file("http://thematicmapping.org/downloads/TM_WORLD_BORDERS_SIMPL-0.3.zip", destfile="world_shape_file.zip")
#unzip("world_shape_file.zip")
#world_spdf=readOGR(dsn = getwd(),layer = "TM_WORLD_BORDERS_SIMPL-0.3")



#-----Preprocessing Data-----#

who_data$Date <- as.Date(who_data$Date_reported)

cols=colnames(pops)
pop_data=pops[,c(cols[1],cols[length(cols)])]
colnames(pop_data)=c("Country","Population")
pop_data$Population=pop_data$Population*1000

covid19_data=merge(x=who_data,y=pop_data,by="Country",all.x=TRUE)


covid19_data$Date_reported=NULL
covid19_data$Country_code=NULL
covid19_data <- covid19_data[order(covid19_data$Country,covid19_data$Date),]
covid19_data=covid19_data[c(1,2,7,8,3,4,5,6)]




#----- Load libraries -----#
library(shiny)
library(shinydashboard)
library(DT)
library(ggplot2)
library(rsconnect)
library(packrat)
library(formattable)
library(leaflet)
library(leaflet.extras)
library(rgdal)
library(sp)
library(raster)
library(RColorBrewer)
library(scales)
library(lattice)
library(dplyr)
library(reshape2)
library(plotly)



# Define UI for application 


ui <- fluidPage(
    dashboardPage(
        dashboardHeader(title="COVID19 Analysis"),
        dashboardSidebar(
            sidebarMenu(
                
                menuItem("Spread of the Virus",
                         tabName="map_spread",
                         icon=icon("viruses")
                ))
        ),
        dashboardBody(
            tabItems(
                
                tabItem(
                    tabName = "map_spread",
                    sliderInput("date_filter", "Date Filter",
                                min = min(covid19_data$Date), max = max(covid19_data$Date), value = min(covid19_data$Date)
                    ),
                    p("Not ready --> need to clean up data"),
                    leafletOutput("world_map")
                    
                )))))

# Define server logic 
server <- function(input, output) {
    
 
    #---------- WORLD MAP ----------#
    
    
    map_filter=reactive({
        filter=subset(covid19_data,Date==input$date_filter)
        return(filter)
    })
    
    
    merge_filter=reactive({
        names(world_spdf)[names(world_spdf) == "NAME"] <- "Country"
        map_data=merge(x=world_spdf,y=map_filter(),by="Country",all.x=TRUE)
    })
    
    
    
    
    #Choropleth Map 
    output$world_map=renderLeaflet({
        bins=c(0,100,500,1000,5000,10000,Inf)
        pal=colorBin(palette = "YlOrBr",domain = merge_filter()$Cumulative_cases,
                     na.color = "transparent",
                     bins=bins)
        customLabel = paste("Country: ",merge_filter()$Country,"<br/>",
                            "Cumulative cases: ",merge_filter()$Cumulative_cases, serp="") %>%
            lapply(htmltools::HTML)
        
        leaflet(merge_filter()) %>%
            addProviderTiles(providers$OpenStreetMap,options=tileOptions(minZoom = 2,
                                                                         maxZoom = 8)) %>%
            addPolygons(fillColor = ~pal(Cumulative_cases),
                        fillOpacity = 0.9,
                        stroke = TRUE,
                        color = "white",
                        highlight=highlightOptions(
                            weight=5,
                            fillOpacity = 0.3
                        ),
                        label=customLabel,
                        weight=0.3,
                        smoothFactor = 0.2) %>%
            
            addLegend(
                pal=pal,
                values = ~Cumulative_cases,
                position = "bottomright",
                title = "Cumulative cases"
            )
    })
    
    
    
}

# Run the application 
shinyApp(ui = ui, server = server)

Can someone help identify the proper way to store shape files when deploying an R Shiny app? I understand when deploying an R Shiny app using Excel files for data, I just store them in the same folder as the app.R file, but it seems these shape files are behaving in a weird way that I can't resolve. Any help would be appreciated! Thank you!

Answer 1

Files required by a published Shiny app should go in a folder named www. If you've got them in the same folder as app.R, they won't be detected properly. No idea why, honestly, but here's a couple resources that mention it:

https://shiny.rstudio.com/images/shiny-cheatsheet.pdf

https://subscription.packtpub.com/book/application_development/9781785280900/8/ch08lvl1sec53/the-www-directory