在Shiny中将本地csv文件的内容另存为矢量

Question

I have a drop-down menu in my UI:

selectInput(inputId = "Header", label = "label", 
            choices = x, 
            selected = NULL),

I would like the variable "x" in the above example to be a character vector containing roughly 100 different options. I have these options saved in a .csv file, but I cannot get the data in the .csv file (which I've uploaded to my directory) to save as a vector. How should I go about saving data from local .csv files into R shiny for use as menu options? I've been trying read.csv among other functions, but no luck so far.

Do I simply have to copy them all over manually? I assume there's an easier way.

Answer 1

Example data
write.table(rownames(mtcars), "mtcars.csv",
            row.names = FALSE, col.names = FALSE, quote = FALSE)

library(shiny)

# User interface that lets you to select input
ui <- fluidPage(
    selectInput("mySelection", "Select input", "")
)

server <- function(input, output, session) {
    observe({
        # Load your csv file
        x <- read.csv("mtcars.csv", header = FALSE)

        # Update selection mySelection (passed to UI)    
        updateSelectInput(session, "mySelection",
            label = "Select input",
            choices = x[, 1],
            selected = x[, 1][1]
        )
    })
}

shinyApp(ui, server)