How to reset an ui in shiny? - r

Question

I created an actionButton RUN demo data as a demonstration of an app and I am wondering how to reset it all so that the user can start his input for user's data sets. I looked around the reset button but still can't get it through.
rm(list=ls())
library(tidyverse)
library(shiny)
# Define UI ----
ui <- fluidPage(
tabsetPanel(
#tabPanel-Input
tabPanel("Input", fluid = TRUE,
# tab title ----
titlePanel("Upload data"),
# sidebar layout with input and output tables ----
sidebarLayout(
# sidebar panel for inputs ----
sidebarPanel(
#show ct demo
actionButton("runexample", "RUN demo data"),
# input1: Select a file ----
fileInput("file1", "Count matrix File (.xlsx)",
multiple = TRUE,
accept = c("text/csv",
"text/comma-separated-values,text/plain",
".csv")),
#input2: select a file ----
fileInput("file2", "Manifest File (.xlsx)",
multiple = TRUE,
accept = c("text/csv",
"text/comma-separated-values,text/plain",
".csv")),
#select column name
selectInput("design", "Column name for analysis", " "),
#select ref group
uiOutput("level0"),
#select study group
uiOutput("level1"),
#action run
actionButton("runbutton", "Run"),
#comment message
p("Click to perform differential gene expression analysis between the selected groups"),
#README link
uiOutput("README"),
#issue report
uiOutput("issue")
),
# Main panel for displaying outputs ----
mainPanel(
# Output: Data file ----
tableOutput("matrix"),
tableOutput("pdat")
)
)
),
#tabPanel-Results
tabPanel("Results", fluid = TRUE,
# App title ----
titlePanel("Download results"),
# Sidebar layout with input and output definitions ----
sidebarLayout(
# Sidebar panel for inputs ----
sidebarPanel(
# Input: Choose dataset ----
selectInput("results", "Choose a dataset:",
choices = c("Results", "Normalized matrix")),
# Button
downloadButton("downloadData", "Download")
),
# Main panel for displaying outputs ----
mainPanel(
tableOutput("table")
)
)
),
#tabPanel-Plots
tabPanel("Plots", fluid = TRUE,
fluidRow(
column(width = 8,
plotOutput("plot1", height = 800,
# Equivalent to: click = clickOpts(id = "plot_click")
click = "plot1_click",
brush = brushOpts(
id = "plot1_brush"
)
)
),
column(width = 4,
h4("Brushed points"),
verbatimTextOutput("brush_info")
)
)
)
)
)
# Define Server ----
server <- function(input, output, session) {
#tabPanel-Input
###demo data
####count
set.seed(123)
ctdemo<- t(rmultinom(1000, size = 50, prob = c(rep(0.4, 4), rep(0.6, 4))))
####manifest
pdemo<-data.frame(Samples=paste0("Sample", 1:8),
Treatment=rep(c("DrugA", "DrugB"), each=4))
###display demo count matrix
observeEvent(input$runexample, {
output$matrix <- renderTable({
head(ctdemo, 10)
})
output$pdat <- renderTable({
head(pdemo, 10)
})
observe({
updateSelectInput(session, "design", choices="Treatment")
})
output$level0 <- renderUI({
selectInput("ref0", "Reference group", "DrugA")
})
output$level1 <- renderUI({
selectInput("ref1", "Study group", "DrugB")
})
})
}
shinyApp(ui, server)

Answer 1

Actually you've made most of the job (I don't copy-paste the full code, it is quite long and the solution is short).
First, create the button "Reset" in the ui part with actionButton("reset", "Reset"), (I placed it just after the button runexample).
Then, put almost of the code of the server part in an observeEvent that is triggered with reset (place this chunk of code at the end of the server part):
observeEvent(input$reset, {
output$matrix <- renderTable(NULL)
output$pdat <- renderTable(NULL)
observe({
updateSelectInput(session, "design")
})
output$level0 <- renderUI(NULL)
output$level1 <- renderUI(NULL)
})
That's it !