Reset FileInputi in Shiny - r

Question

I have a shiny app with fileInput.
I created a reset button to clear the file from the fileInput. I know the file is cached in the shiny memory, but I just want to reset the FileInput object to look like how it originally did before I uploaded the file, when I press the reset button.
I googled a bit and found most people get around this problem using shinyjs, but shinyjs does not work in the R package I am creating so I am trying to find a work around.
I insert a executable code below!
library(shiny)
library(shinythemes)
ui <- fluidPage(
titlePanel("Old Faithful Geyser Data"),
fileInput(inputId = "ABC", label = "Input File", multiple = FALSE, accept = NULL,
width = "20%", buttonLabel = "Browse...",
placeholder = "You didn't choose any files to test, so select beside"),
sidebarLayout(
sidebarPanel(h4("Select the best the number of bins"),
br(),
br(),
sliderInput("bins",
"Number of bins:",
min = 1,
max = 50,
value = 30),
actionButton("reset", "Reset"),
),
mainPanel(
plotOutput("distPlot")
)
)
)
server <- function(input, output,session) {
output$distPlot <- renderPlot({
x <- faithful[, 2]
bins <- seq(min(x), max(x), length.out = input$bins + 1)
hist(x, breaks = bins, col = 'darkgray', border = 'white')
})
observeEvent(input$reset, {
updateSliderInput(session,"bins",value = 1)
})
}
shinyApp(ui = ui, server = server)

Answer 1

One way would be to use fileInput dynamically from server side, so when the reset button is clicked you can reload the input.
library(shiny)
library(shinythemes)
ui <- fluidPage(
titlePanel("Old Faithful Geyser Data"),
uiOutput('file'),
sidebarLayout(
sidebarPanel(h4("Select the best the number of bins"),
br(),
br(),
sliderInput("bins",
"Number of bins:",
min = 1,
max = 50,
value = 30),
actionButton("reset", "Reset"),
),
mainPanel(
plotOutput("distPlot")
)
)
)
server <- function(input, output,session) {
output$distPlot <- renderPlot({
x <- faithful[, 2]
bins <- seq(min(x), max(x), length.out = input$bins + 1)
hist(x, breaks = bins, col = 'darkgray', border = 'white')
})
output$file <- renderUI({
fileInput(inputId = "ABC", label = "Input File", multiple = FALSE, accept = NULL,
width = "20%", buttonLabel = "Browse...",
placeholder = "You didn't choose any files to test, so select beside")
})
observeEvent(input$reset, {
updateSliderInput(session,"bins",value = 1)
output$file <- renderUI({
fileInput(inputId = "ABC", label = "Input File", multiple = FALSE, accept = NULL,
width = "20%", buttonLabel = "Browse...",
placeholder = "You didn't choose any files to test, so select beside")
})
})
}
shinyApp(ui = ui, server = server)