I want to update output data on update button every time.
Here is my code which show the output on update button for the first time I run the code but in runtime if the input is changed, the output is updated automatically.
library(shiny)
ui <- fluidPage(
titlePanel("My Shop App"),
sidebarLayout(
sidebarPanel(
helpText("Controls for my app"),
selectInput("item",
label = "Choose an item",
choices = list("Keyboard",
"Mouse",
"USB",
sliderInput("price",
label = "Set Price:",
min=0, max = 100, value=10),
actionButton ("update","Update Price")
),
mainPanel(
helpText("Selected Item:"),
verbatimTextOutput("item"),
helpText("Price"),
verbatimTextOutput("price")
)
)
)
server <- function(input, output) {
SelectInput <- eventReactive (input$update , {
output$item = renderText(input$item)
output$price = renderText(input$price)
})
output$item <- renderText(SelectInput())
output$price <- renderText(SelectInput())
}
shinyApp(ui = ui, server = server)
Either create a dependency and put them into the reactive and return it:
server <- function(input, output) {
SelectInput <- eventReactive(input$update,{
list(item = input$item, price = input$price)
})
output$item <- renderText(SelectInput()$item)
output$price <- renderText(SelectInput()$price)
}
Or you can isolate, but then you have to add the button reaction to each listener
server <- function(input, output) {
output$item <- renderText({
req(input$update)
input$update
isolate(input$item)
})
output$price <- renderText({
req(input$update)
input$update
isolate(input$price)
})
}
Related
I've got a table that will initialize, but will not update. I use a few inputs, which then get called by a function to calculate the outputs. They will initialize with the correct values, but when I click the actionButton, nothing happens.
output$view<-renderTable({
tabSvol<-isolate(
data.frame(
S=c(
func1(input$in1),
func2(input$in2),
func3(input$in1,input$2)
)
)
)
tabSvol
})
Here's a MRE that allows you to add rows to a reactive table.
library(shiny)
library(tidyverse)
ui <- fluidPage(
numericInput("a", "A: ", value=NA),
selectInput("b", "B:", choices=c("X", "Y", "Z")),
actionButton("add", "Add row"),
tableOutput("table")
)
server <- function(input, output) {
rv <- reactiveValues(table=tibble(A=numeric(0), B=character(0)))
output$table <- renderTable({
rv$table
})
observeEvent(input$add, {
rv$table <- rv$table %>% add_row(A=input$a, B=input$b)
})
}
shinyApp(ui = ui, server = server)
I have a simple task of printing the output of a call to table() on a selected variable.
I want to display the output when the button "Print" is clicked.
In the following example, once the button is clicked, the output is always triggered when I change the selected variable.
If I clicked "Print", and then change the selected variable, I want the ouput to be gone, waited to be printed again when clicking "Print".
Thank you!
Here is a reproducible example:
library(shiny)
data = iris
ui = fluidPage(
uiOutput("selectvar"),
actionButton("print", "Print"),
verbatimTextOutput("info")
)
server = function(input, output, session)
{
output$selectvar = renderUI({
selectInput("selectedvar",
"Select variable",
choices = colnames(iris))
})
tab = reactive( table(data[[input$selectedvar]]) )
observeEvent(input$print, {
output$info = renderPrint( tab() )
})
}
shinyApp(ui, server)
That's because output$info is reactive to tab(), even while it is enclosed in an observeEvent. I think this app does what you want:
library(shiny)
data = iris
ui = fluidPage(
uiOutput("selectvar"),
actionButton("print", "Print"),
verbatimTextOutput("info")
)
server = function(input, output, session)
{
output$selectvar = renderUI({
selectInput("selectedvar",
"Select variable",
choices = colnames(iris))
})
tab <- reactiveVal()
observeEvent(input$selectedvar, {
tab(NULL)
})
observeEvent(input$print, {
tab(table(data[[input$selectedvar]]))
})
output$info <- renderPrint({
tab()
})
}
shinyApp(ui, server)
I want to add the input text to a vector in a Shiny app every time a button is clicked. This is the example I'm working with:
library(shiny)
ui <- fluidPage(
textInput(inputId = "inquiry", label = "enter text"),
actionButton(inputId = "searchButton", label = "Run"),
verbatimTextOutput("queryList", placeholder = FALSE)
)
server <- function(input, output, session) {
queryList <- c()
observeEvent(input$searchButton, {
queryList[length(queryList)+1] <- input$inquiry
output$queryList <- renderPrint({
queryList
})
})
}
shinyApp(ui = ui, server = server)
So if "item1" is entered and the button is clicked, then "item2" is entered and the button is clicked again, queryList should look like c("item1", "item2"), but it seems to just be replacing "item1" with "item2". I'm sure I'm missing something very simple...queryList[length(queryList)+1] looks a little strange, but it works in a non-reactive environment.
Making queryList reactive fixed it for me:
library(shiny)
ui <- fluidPage(
textInput(inputId = "inquiry", label = "enter text"),
actionButton(inputId = "searchButton", label = "Run"),
verbatimTextOutput("queryList", placeholder = FALSE)
)
server <- function(input, output, session) {
queryList <- reactiveValues()
queryList$values <- c()
observeEvent(input$searchButton, {
queryList$values[length(queryList$values) + 1] <- input$inquiry
})
output$queryList <- renderPrint({
if (!is.null(queryList$values)) {
queryList$values
}
})
}
shinyApp(ui = ui, server = server)
I am trying to adapt R Shiny: automatically refreshing a main panel without using a refresh button to a new minimal working example:
ui <- fluidPage(
pageWithSidebar(
headerPanel("actionButton test"),
sidebarPanel(
numericInput("n", "N:", min = 0, max = 100, value = 50),
br(),
actionButton("goButton", "Go!"),
p("Click the button to update the value displayed in the main panel."),
actionButton("newButton", "New Button"),
actionButton("newButton2", "Another New Button")
),
mainPanel(
verbatimTextOutput("nText"),
textOutput("some_text_description"),
plotOutput("some_plot")
)
)
)
server <- function(input, output, session) {
# builds a reactive expression that only invalidates
# when the value of input$goButton becomes out of date
# (i.e., when the button is pressed)
ntext <- eventReactive(input$goButton, {
input$n
})
output$nText <- renderText({
ntext()
})
# Prep some text for output
output$some_text_description <- renderText({
if (input$newButton == 0) {return(NULL)}
else {
"Lorem ipsum dolorom."
}
})
# Prep some figure for output
# Simple Bar Plot
output$some_plot <- renderPlot({
if (input$newButton2 == 0) {return(NULL)}
else {
counts <- table(mtcars$gear)
barplot(counts, main="Car Distribution", xlab="Number of Gears")
}
})
}
shinyApp(ui = ui, server = server)
In the code above, I have three actionButton commands, one which produces a plot, one which produces text output, and one which produces a number (as verbatim text output). As you click through each button, new output appears alongside previously generated output (from the last button you pressed).
Without needing to implement a refresh button that clears everything manually, how do I get each actionButton to override (i.e., wipe) the output of the others automatically without them all stacking atop of each other in the main panel. My understanding is that I need to use some combination of observeEvent, NULL, and reactiveValues but my attempts have so far been unsuccessful.
You can use renderUI() for that.
output$all <- renderUI({
global$out
})
Within a global reactiveValue global$out you can store which ui element you would like to display. (Initially it should be empty, therefore NULL).
global <- reactiveValues(out = NULL)
And then listen for the clicks in the Buttons and update global$out accordingly.
observeEvent(input$goButton, {
global$out <- verbatimTextOutput("nText")
})
observeEvent(input$newButton, {
global$out <- textOutput("some_text_description")
})
observeEvent(input$newButton2, {
global$out <- plotOutput("some_plot")
})
Full app would read:
library(shiny)
ui <- fluidPage(
pageWithSidebar(
headerPanel("actionButton test"),
sidebarPanel(
numericInput("n", "N:", min = 0, max = 100, value = 50),
br(),
actionButton("goButton", "Go!"),
p("Click the button to update the value displayed in the main panel."),
actionButton("newButton", "New Button"),
actionButton("newButton2", "Another New Button")
),
mainPanel(
uiOutput("all")
)
)
)
server <- function(input, output, session) {
global <- reactiveValues(out = NULL)
observeEvent(input$goButton, {
global$out <- verbatimTextOutput("nText")
})
observeEvent(input$newButton, {
global$out <- textOutput("some_text_description")
})
observeEvent(input$newButton2, {
global$out <- plotOutput("some_plot")
})
output$all <- renderUI({
global$out
})
output$nText <- renderText({
input$n
})
output$some_text_description <- renderText({
"Lorem ipsum dolorom."
})
# Simple Bar Plot
output$some_plot <- renderPlot({
counts <- table(mtcars$gear)
barplot(counts, main="Car Distribution", xlab="Number of Gears")
})
}
shinyApp(ui = ui, server = server)
I'm trying to append a value taken from an input (in the present case input$n) to a list (in the present case the variable "keyword_list"), when the user presses the an action button (in the present case the button input$goButton).
ui.R
library(shiny)
pageWithSidebar(
headerPanel("actionButton test"),
sidebarPanel(
#numericInput("n", "N:", min = 0, max = 100, value = 50),
textInput("n", "Caption", "Enter next keyword"),
br(),
actionButton("goButton", "Go!"),
p("Click the button to update the value displayed in the main panel.")
),
mainPanel(
verbatimTextOutput("nText"),
dataTableOutput('mytable')
)
)
})
server.R
library(shiny)
# Define server logic required to summarize and view the selected
# dataset
function(input, output,session) {
#prepare data
keyword_list <- matrix()
makeReactiveBinding('keyword_list')
observe({
if (input$goButton == 0)
return()
isolate({
keyword_list <- append(keyword_list,input$n) })
})
ntext <- eventReactive(input$goButton, {
input$n
})
output$nText <- renderPrint({
#input$n
ntext()
})
output$mytable = renderDataTable({
as.data.frame(keyword_list)
})
}
How about this:
library(shiny)
ui <- pageWithSidebar(
headerPanel("actionButton test"),
sidebarPanel(
#numericInput("n", "N:", min = 0, max = 100, value = 50),
textInput("n", "Caption", "Enter next keyword"),
br(),
actionButton("goButton", "Go!"),
p("Click the button to update the value displayed in the main panel.")
),
mainPanel(
verbatimTextOutput("nText"),
dataTableOutput('mytable')
)
)
})
library(shiny)
# Define server logic required to summarize and view the selected
# dataset
server <- function(input, output,session) {
global <- reactiveValues(keyword_list = "")
observe({
if (input$goButton == 0)
return()
isolate({
global$keyword_list <- append(global$keyword_list, input$n)
})
})
ntext <- eventReactive(input$goButton, {
input$n
})
output$nText <- renderPrint({
#input$n
ntext()
})
output$mytable = renderDataTable({
as.data.frame(global$keyword_list)
})
}
shinyApp(ui, server)