在闪亮的应用程序中保存文件路径和上传文件的名称以便处理它们

Question

我试图在下面一个闪亮的应用程序中上传一个 shapefile，但正如你所看到的，我面临一个错误Error in ogrListLayers: Cannot open data source 。 我怀疑问题可能是文件路径没有被正确读取，所以我希望在上传新文件后立即保存文件路径和文件名，然后进行相应处理以得出以下结论： readOGR("/home/lucho/data/EnglandGIS/england_gor_2011.shp")或readOGR(dsn = "/home/lucho/data/EnglandGIS/", layer = "england_gor_2011")我相信这没问题。

library(shiny)
library(rgdal)
library(DT)

# ui object
ui <- fluidPage(
    titlePanel(p("Spatial app", style = "color:#3474A7")),
    sidebarLayout(
        sidebarPanel(
            fileInput(
                inputId = "filemap",
                label = "Upload map. Choose shapefile",
                multiple = TRUE,
                accept = c(".shp", ".dbf", ".sbn", ".sbx", ".shx", ".prj")
            )
            
            
        ),
        
        mainPanel(
            
            DTOutput(outputId = "table")
        )
    )
)

# server()
server <- function(input, output) {
   
    
    map <- reactive({
        req(input$filemap)
        
        # shpdf is a data.frame with the name, size, type and
        # datapath of the uploaded files
        shpdf <- input$filemap
        
        # The files are uploaded with names
        # 0.dbf, 1.prj, 2.shp, 3.xml, 4.shx
        # (path/names are in column datapath)
        # We need to rename the files with the actual names:
        # fe_2007_39_county.dbf, etc.
        # (these are in column name)
        
        # Name of the temporary directory where files are uploaded
        tempdirname <- dirname(shpdf$datapath[1])
        
        # Rename files
        for (i in 1:nrow(shpdf)) {
            file.rename(
                shpdf$datapath[i],
                paste0(tempdirname, "/", shpdf$name[i])
            )
        }
        
        # Now we read the shapefile with readOGR() of rgdal package
        # passing the name of the file with .shp extension.
        
        # We use the function grep() to search the pattern "*.shp$"
        # within each element of the character vector shpdf$name.
        # grep(pattern="*.shp$", shpdf$name)
        # ($ at the end denote files that finish with .shp,
        # not only that contain .shp)
        map <- readOGR(paste(tempdirname,
                             shpdf$name[grep(pattern = "*.shp$", shpdf$name)],
                             sep = "/"
        ))
        data.frame(map)
    })
    
    output$table <- renderDT(map())
    
   
}

# shinyApp()
shinyApp(ui = ui, server = server)