Disabling buttons in Shiny - r

I am writing some Shiny code where the user will enter some inputs to the app and then click a an action button. The action button triggers a bunch of simulations to run that take a long time so I want once the action button is clicked for it to be disabled so that the user can't keep clicking it until the simulations are run. I came across the shinyjs::enable and shinyjs::disable functions but have been having a hard time utilizing them. Here is my server code:
output$button1= renderUI({
if(input$Button1 > 0) {
shinyjs::disable("Button1")
tableOutput("table")
shinyjs::enable("Button1")}
})
However, when I use this code, and click the action button nothing happens. I.e., teh action button doesn't grey out nor does the table get generated. However, when I take away the shinyjs::enable() command, i.e.,
output$button1= renderUI({
if(input$Button1 > 0) {
shinyjs::disable("Button1")
tableOutput("table")
}
})
The table gets generated first, and then the button goes grey, however I would have expected the button to go grey and then the table to generate itself.
What am I doing wrong here?
Here is my updated code based on Geovany's suggestion yet it still doesn't work for me
Button1Ready <- reactiveValues(ok = FALSE)
observeEvent(input$Button1, {
shinyjs::disable("Button1")
RunButton1Ready$ok <- FALSE
RunButton1Ready$ok <- TRUE
})
output$SumUI1= renderUI({
if(Button1Ready$ok){
tableOutput("table")
shinyjs::enable("Button1")
}
})
where for clarification I have also:
output$table <- renderTable({
#My code....
)}

I think that you are using shinyjs::disable and shinyjs::enable in the same reactive function. You will only see the last effect. I will recommend you to split in different reactive functions the disable/enable and use an extra reactive variable to control the reactivation of the button.
I don't know how exactly your code is, but in the code below the main idea is illustrated.
library(shiny)
library(shinyjs)
ui <- fluidPage(
shinyjs::useShinyjs(),
sidebarLayout(
sidebarPanel(
actionButton("Button1", "Run"),
shinyjs::hidden(p(id = "text1", "Processing..."))
),
mainPanel(
plotOutput("plot")
)
)
)
server <- function(input, output) {
plotReady <- reactiveValues(ok = FALSE)
observeEvent(input$Button1, {
shinyjs::disable("Button1")
shinyjs::show("text1")
plotReady$ok <- FALSE
# do some cool and complex stuff
Sys.sleep(2)
plotReady$ok <- TRUE
})
output$plot <-renderPlot({
if (plotReady$ok) {
shinyjs::enable("Button1")
shinyjs::hide("text1")
hist(rnorm(100, 4, 1),breaks = 50)
}
})
}
shinyApp(ui, server)

Related

Force input widget creation in Shiny even if widget has not yet been displayed in browser

In Shiny, one can use the following line to force displaying/refreshing an output even if not displayed within the ui:
outputOptions(output, "my_output", suspendWhenHidden = FALSE)
Is there a similar way to "force" input widget creation?
My context: I do have a button that pre-populate a textinput on another tab. Potentially, this textinput may not been generated yet if user didn't go to this specific tab. In such a case, the pre-population legitimely fails.
Good practice would probably be to use a reactiveValues, to feed it with the "pre-populate value" when clicking the button, and then to use this rv within the input widget creation. But I was wondering if a similar option as the above was available in Shiny.
Here’s a simple, working example of the situation I think you are describing.
That is, you don’t need to do anything special.
library(shiny)
ui <- fluidPage(
tabsetPanel(
tabPanel("A", actionButton("populate", "Populate B things")),
tabPanel("B", textInput("b_text", "Add some B text"))
)
)
server <- function(input, output, session) {
observeEvent(input$populate, {
updateTextInput(session, "b_text", value = "Updated from tab A")
})
}
shinyApp(ui, server)
If the input you want to update is generated with uiOutput() then you can
use outputOptions() to force evaluation, like you already mentioned:
library(shiny)
ui <- fluidPage(
tabsetPanel(
tabPanel("A", actionButton("populate", "Populate B things")),
tabPanel("B", uiOutput("b_panel"))
)
)
server <- function(input, output, session) {
observeEvent(input$populate, {
updateTextInput(session, "b_text", value = "Updated from tab A")
})
output$b_panel <- renderUI({
textInput("b_text", "Add some B text")
})
outputOptions(output, "b_panel", suspendWhenHidden = FALSE)
}
shinyApp(ui, server)

Why is my remove UI function in R shiny not working?

I've reviewed similar posts and haven´t found any that address this specific need. Below is very simple MWE of what I'm trying to do: shown in 2 images, and in runnable code. My "Hide" button (or remove UI) doesn't work. Help!! I'm sure it's a simple solution but I'm new to this.
What I'm trying to do: Click on the "Add" button and a file input prompt appears below. Click "Hide" button and the file input prompt goes away. Click "Add" again (after "Hide") and the file input prompt appears again. If you click "Add" now (and repeatedly), that single file input prompt remains. (Most other posts have the object appearing repeatedly, again and again in a growing column, with every additional click of the button - this isn't what I need). Just one click to make it appear (and clicking "Add" over and over just keeps it there in its original single manifestation), and "Hide" makes it go away. Simple as that.
Images:
library(shiny)
ui <- fluidPage(
h2("Testing showing and hiding of a function in UI ..."),
br(),
h3(actionButton("addBtn", "Add")),
h3(actionButton("hideBtn","Hide")),
uiOutput("FileInput"),
) # close fluid page
server <- function(input, output, session) {
output$FileInput <- renderUI({
"txt"
req(input$addBtn)
tagList(fileInput("file1", "Choose file",multiple= FALSE,
accept=c("csv",
"comma-separated-values",
".csv"), # close c
width=250,
buttonLabel = "select one file",
placeholder = "Add file"
), # close file input
)} # close tag list
)} # close render UI
observeEvent(input$hideBtn, {
removeUI(
selector = "div:has(> #txt)")
}) # close observe event
shinyApp(ui, server)
Perhaps you can use shinyjs package to get the desired result. Try this
library(shiny)
library(shinyjs)
ui <- fluidPage(
useShinyjs(),
h2("Testing showing and hiding of a function in UI ..."),
br(),
h3(actionButton("addBtn", "Add")),
h3(actionButton("hideBtn","Hide")),
uiOutput("FileInput"),
) # close fluid page
server <- function(input, output, session) {
output$FileInput <- renderUI({
"txt"
req(input$addBtn)
tagList(fileInput("file1", "Choose file",multiple= FALSE,
accept=c("csv",
"comma-separated-values",
".csv"), # close c
width=250,
buttonLabel = "select one file",
placeholder = "Add file"
) # close file input
) # close tag list
}) # close render UI
observeEvent(input$addBtn, {
shinyjs::show("FileInput")
})
observeEvent(input$hideBtn, {
shinyjs::hide("FileInput")
#removeUI(selector = "div:has(> #txt)")
})
}
shinyApp(ui, server)
If you do not want to use shinyjs package, you can use insertUI and removeUI as shown below.
library(shiny)
ui <- fluidPage(
h2("Testing showing and hiding of a function in UI ..."),
br(),
h3(actionButton("addBtn", "Add")),
h3(actionButton("hideBtn","Hide")),
uiOutput("FileInput"),
) # close fluid page
server <- function(input, output, session) {
output$FileInput <- renderUI({
req(input$addBtn)
tagList(tags$div(id = 'placeholder1')
) # close tag list
}) # close render UI
observeEvent(input$addBtn, {
if (input$addBtn==0){return(NULL)
}else {
insertUI(
selector = '#placeholder1' ,
## wrap element in a div with id for ease of removal
ui = tags$div(id="fi",
div(style="display: inline-block; width: 185px ;" ,
fileInput("file1", "Choose file",multiple= FALSE,
accept=c("csv",
"comma-separated-values",
".csv"), # close c
width=250,
buttonLabel = "select one file",
placeholder = "Add file"
) # close file input
))
)
}
})
observeEvent(input$hideBtn, {
if (input$hideBtn==0){return(NULL)
}else {
removeUI(selector = "div:has(> #fi)")
}
})
}
shinyApp(ui, server)

R Shiny toggle text of actionLink

I am trying to do something which I thought would be relatively simple, but I cannot seem to figure it out.
I am attempting to have an actionLink which, when pressed, provides additional information for the user. When pressed again it hides the information. I can do this fine, but what I am struggling with is updating the text of the actionLink.
I want it to read "Show additional" when the extra information is hidden, and then "Hide additional" when the information is exposed. I have read the following questions/answers, but cannot quite get it to work.
Modify shiny action button once it is clicked
Update label of actionButton in shiny
I have provided a simple code for this below, though the real example will be a lot more complex.
Thank you for your time and help.
shinyApp(
ui = shinyUI(fluidPage(useShinyjs(),
actionLink("button", "Show additional"),
hidden(
div(id='text_div',
verbatimTextOutput("text")
)
)
)
),
server = function(input, output, session){
observeEvent(input$button, {
toggle('text_div')
output$text <- renderText({"Additional"})
})
}
)
You can check for the value of input$button(which increments by 1 each time you click on it) and update the actionLink label parameter in function of its value with updateActionButton :
shinyApp(
ui = shinyUI(
fluidPage(useShinyjs(),
actionLink("button", "Show additional"),
hidden(div(id='text_div', verbatimTextOutput("text")))
)
),
server = function(input, output, session){
observeEvent(input$button, {
toggle('text_div')
output$text <- renderText({"Additional"})
if (input$button %% 2 == 1) {
txt <- "Hide Additional"
} else {
txt <- "Show Additional"
}
updateActionButton(session, "button", label = txt)
})
}
)

Unfocus an action button after a click (Shiny)

This is a bit minor, but after clicking an action button (normally light gray) in a Shiny app, it turns a darker gray and the focus remains on it. The user has to click somewhere else for the action button to return to its normal lighter color.
Try it out here: http://shiny.rstudio.com/gallery/actionbutton-demo.html
The lack of automatically reverting to a lighter color means the user doesn't get a visual feedback that the button was successfully pressed.
Is there a way to fix this?
Another way of doing it is by disabling the button while the process is running, it will also prevent people from re-clicking it while you are waiting on the result. Have a look at shinyjs package which has a lot of nice features. Note that I added 2 second delay to mimic long operation.
rm(list=ls())
library(shinyBS)
library(shiny)
library(shinyjs)
ui <- pageWithSidebar(
headerPanel("actionButton test"),
sidebarPanel(numericInput("n", "N:", min = 0, max = 100, value = 50),
tags$div(style="display:inline-block",title="Push Me",bsButton("goButton", label = "Button", block = TRUE,style="primary"))
),
mainPanel(useShinyjs(),verbatimTextOutput("nText")
)
)
server <- shinyServer(function(input, output,session) {
ntext <- eventReactive(input$goButton, {
shinyjs::disable("goButton")
Sys.sleep(2)
shinyjs::enable("goButton")
input$n
})
output$nText <- renderText({ntext()})
})
shinyApp(ui = ui, server = server)
Disabled Button
Enabled Button
You can tell the webbrowser to unfocus the actionbutton, when it is clicked. This way, you don't get the effects you describe. Below is a (more or less) two line JavaScript call to achieve this. The script reads very straightforward. When the document is ready, we add a functionality, that if a button is clicked, then it is blurred immediately (looses focus).
library(shiny)
ui <- shinyUI(pageWithSidebar(
headerPanel("actionButton test"),
sidebarPanel(
tags$script(HTML("
$(document).ready(function() {
$('.btn').on('click', function(){$(this).blur()});
})
")),
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.")
),
mainPanel(
verbatimTextOutput("nText")
)
))
server <- function(input, output) {
# 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()
})
}
shinyApp(ui, server)

shiny checkbox unchecks - cross-referring to inputs in same renderUI call

I intended to have some optional extra buttons appearing in my shiny app using renderUI. I would prefer to have new buttons inserted in the one and same renderUI call. I wrote a renderUI expession were the second button only is rendered if input of fist button is not null and(&&) is TRUE. It does not work as first button rapidly unchecks itself again whenever checked. I made a solution by splitting into two renderUI calls.
My question are:
Why exactly does the first code piece fail?
Would it be possible to achieve what the second code piece does in only one renderUI call?
.
library(shiny)
ui = fluidPage(
uiOutput("checkUI")
)
server = function(input,output) {
output$checkUI = renderUI({
list(
checkboxInput('check1',"check me first"),
if(!is.null(input$check1)&&input$check1==T) {
checkboxInput('check2',"check me to win")
} else {
NULL
}
)
})
}
shinyApp(ui,server)
but this works...
ui = fluidPage(
uiOutput("checkUI"),
uiOutput("textUI")
)
server = function(input,output) {
#UI first button
output$checkUI = renderUI({
list(
checkboxInput('check1',"check me first")
)
})
#UI second button
output$textUI = renderUI({
list(
if(!is.null(input$check1) && input$check1)
checkboxInput('check2',"check me to win") else NULL
)
})
}
shinyApp(ui,server)
Your first piece of code fails because the renderUI runs every time there is a change in input, so when you check the first check box. Since you have:
checkboxInput('check1',"check me first")
The renderUI immediately resets the input$check1 and then the renderUI is run again, unsetting the checkbox. This is why the second checkbox briefly flashes.
Luckily this is a common problem, so there is a Shiny solution to this with conditionalPanels:
library(shiny)
ui = fluidPage(
checkboxInput('check1',"check me first"),
conditionalPanel(
condition = "input.check1 == true",
checkboxInput("check2", "check me to win")
)
)
server = function(input,output){
}
shinyApp(ui,server)

Resources