Hi, I built a shinyapp to generate a report containing map images according to input coordinates. It works fine locally but not the case with shinyapps.io. I'm thinking I must make some mistakes on the folder path since I'm using leaflet and mapview, which saves the static map as a png file then print it.
The following is a simple version of my application:
app.R
library(leaflet)
library(mapview)
library(leaflet.providers)
shinyApp(
ui = fluidPage(
textInput("Lat", "lat", 45),
textInput("Lon", "lon", -93),
downloadButton("report", "Generate report")
),
server = function(input, output) {
output$report <- downloadHandler(
filename = "report.pdf",
content = function(file) {
# Copy the report file to a temporary directory before processing it, in
# case we don't have write permissions to the current working dir (which
# can happen when deployed).
tempReport <- file.path(tempdir(), "report.Rmd")
file.copy("report.Rmd", tempReport, overwrite = TRUE)
# Set up parameters to pass to Rmd document
params <- list(lat = input$Lat, lon = input$Lon)
# Knit the document, passing in the `params` list, and eval it in a
# child of the global environment (this isolates the code in the document
# from the code in this app).
rmarkdown::render(tempReport, output_file = file,
params = params,
envir = new.env(parent = globalenv())
)
}
)
}
)
report.rmd
---
title: "Map Report"
always_allow_html: yes
linestretch: 1.25
fontsize: 12pt
output:
pdf_document:
params:
lat: NA
lon: NA
---
```{r, echo=FALSE}
# The `params` object is available in the document.
sprintf("Input lat is %s", params$lat)
sprintf("Input lon is %s", params$lon)
Map
m <- leaflet() %>%
addProviderTiles('Esri.WorldImagery') %>%
setView(params$lon, params$lat, zoom = 20) %>%
addPopups(lng = as.numeric(params$lon), lat = as.numeric(params$lat), popup = sprintf("%.2f, %.2f", as.numeric(params$lat), as.numeric(params$lon)))
mapshot(m, file = "map.png", remove_url = TRUE)
r sprintf("", "map.png")
shinyapps.io gave errors as follows:
2020-07-14T19:56:51.137171+00:00 shinyapps[2570823]: ! Package pdftex.def Error: File `map.png' not found.
2020-07-14T19:56:51.137173+00:00 shinyapps[2570823]:
2020-07-14T19:56:51.139603+00:00 shinyapps[2570823]: Warning: Error in : LaTeX failed to compile /tmp/RtmpcILEaW/file181ec0cbc2.tex. See https://yihui.org/tinytex/r/#debugging for debugging tips. See file181ec0cbc2.log for more info.
2020-07-14T19:56:51.144014+00:00 shinyapps[2570823]: [No stack trace available]
Thanks for your help!