I'm attempting to design a Shiny App where the user changes several inputs, then presses a "Plot" button to generate new visualizations. Currently, I have the a data object being generated in an eventReactive tied to the "Plot" button, with that data then getting fed into the renderPlot functions.
The framework seems to work, except that the plots will change whenever the inputs are changed. This often leads to errors in the plots, as different inputs load in different data. Pressing the "Plot" button after changing the inputs will cause the correct plots to render, but I'm trying to find a way to ensure that the plots don't change ever until that button is hit.
I believe the solution is a use of the "isolation" function, and I've tried that just about everywhere. However, none of these attempts have been successful. Below is a (simplified) setup of my code.
ui <- fluidPage(
sidebarLayout(
sidebarPanel(
# several selectInput options
actionButton('plot', label = 'Plot')
)
mainPanel(
plotOutput('outputPlot', height = '3in'),
)
)
)
server <- function(input, output) {
plotData <- eventReactive(input$plot, {
# load various data and organize into a list
return(data.list)
})
outPutPlot <- renderPlot({
plot.data <- plotData()
# manipulate data based on the specific plot, then generate
return(plot)
)
}
You’re right that you’d need to isolate() all reactive dependencies other
than plotData(). Without having a complete runnable example, it’s not
possible to point out where this might have gone wrong. However, it may be
easier to wrap the renderPlot() call in bindEvent(), which will isolate
everything. You just pass the expressions you want to depend on in other
arguments.
So try something like this:
bindEvent(renderPlot({ ... }), plotData())
Related
I'm using the awesome shinyMobile package to create a mobile app. It has 4 tabs (f7Tab()), including a dashboard tab where I load all my charts. The idea is to load the charts when the user shifts to the tab so they don't slow down the initial app load, but also ONLY LOAD THE GRAPHS ONCE unless an input is triggered.
Here is a sample of my server code (there are multiple graphs like this):
# Reactively render timeseries graph
observe({
# Check which tab is opened (tab label should be 'Dashboard')
if (reactiveVal(input$mainTabs)() == 'Dashboard') {
output$tseriesGraph <- renderPlotly({
tseries_basic(input$tseriesVar)
})
}
})
And the corresponding UI code:
# Timeseries plots
f7AccordionItem(
id='tseriesAccord',
title='Timeseries of individual variables',
# Choose var to plot
f7Select(
'tseriesVar',
'Choose variable to plot:',
selected=chosen_vars[1],
choices=chosen_vars
),
br(),
withSpinner(plotlyOutput("tseriesGraph",
height='350px')
)
)
As it stands, every time the user switches back to the Dashboard tab, all of the graphs get reloaded by the server, even if they were previously loaded. How can I prevent Shiny from reloading these graphs unnecessarily?
(Also, out of curiosity, is there any way to get the graphs to load when the f7AccordionItem with id=tseriesAccord is loaded? Doesn't seem to be an id argument for this function.)
Thanks very much!
I ended up finding a workaround: use f7Accordion id to determine whether the graph should load or not. So don't even need to use the code to check whether my Dashboard was open. I needed to use the 'state' object, which shows as TRUE or FALSE depending on whether the f7AccordionItem under f7Accordion is open.
Example:
# Server
observe(if (input$spagBasicAccord$state) {
output$spagBasicGraph <- renderPlotly({
spag_basic(input$spagBasicVar)
})
})
# UI
# Basic spaghetti graph
f7Accordion(
id='spagBasicAccord',
f7AccordionItem(
title='Basic spaghetti graph',
f7Select(
'spagBasicVar',
'Choose variable to plot:',
selected=chosen_vars[1],
choices=chosen_vars
),
br(),
withSpinner(plotlyOutput("spagBasicGraph",
height='350px')
)
)
)
I'm fairly new to R Shiny but am stuck with the following problem for some time now and hope you can provide some help:
I try to refresh a plot in R shiny that should be refreshed if either a new input argument is entered OR an action button is pressed. This should be straightforward, but unfortunately I can't solve it, despite googling/reading instructions for some time. Any advice would be recommended. Any solutions on the web seem to put the whole renderplot function inside the observeEvent function, but I also need the renderplot in addition outside of it to account for the possibility of just entering inputs without pressing the action button.
I have no trouble creating a (render)plot that either exclusively is refreshed when entering a new input or exclusively refreshed when pressing a button.
However when doing both at the same I fail: I first tried to copy the renderplot function including the resulting output twice one time within an observeEvent function (to account for clicking the action button) and one time outside of an observeEvent (to account for only refreshing the inputs to the plot) but this leads only to a greyed out graph that refreshes after ~10 seconds delay when pressing the action button. I imagine adding the reactive click input generated from clicking the action button directly to the renderplot outside of observe event , but so far I couldn't get it to run. Any recommendations would be much appreciated.
Thank you in advance.
Like this?:
Edit: No need to pass the selectInput to the reactive Vals.. this does the same:
library(shiny)
ui <- fluidPage(
sidebarLayout(
sidebarPanel(
selectInput(inputId="select", label="title", choices=LETTERS[1:3], selected = "A"),
actionButton(inputId="btn", label="refresh")
),
mainPanel(
plotOutput("scatterPlot")
)
)
)
server <- function(input, output) {
plotSettings <- reactiveValues()
observeEvent(c(input$btn, input$select), {
plotSettings$values <- runif(100,1,100)
# plotSettings$title <- input$select
}, ignoreNULL = FALSE)
output$scatterPlot <- renderPlot({
plot(plotSettings$values, main=input$select)
})
}
shinyApp(ui = ui, server = server)
My goal is to have a tabsetPanel wrapped in a conditionalPanel whose condition is a global variable being false.
ui.R
mainPanel(
conditionalPanel("searchPage == \"false\"",
tabsetPanel(
tabPanel("Summary",htmlOutput("summary")),
tabPanel("Description", htmlOutput("description"))
))),
global.R
searchPage <- "true"
then in server.R I assign new values to it a few different times, but all like this:
observeEvent(input$openButton,
output$results <- renderUI({
textOutput("")
searchPage <- "false"
}))
No matter what I do, I always get "Uncaught ReferenceError: searchPage is not defined". I've tried changing the global.R to multiple different combinations of using quotes, not using quotes, using <- or <<-, making it this.searchPage, my.searchPage and numerous other things (of course always making server.R and ui.R match too), but haven't had much luck at all.
As mentioned in a comment on the question's post, this is a perfect usecase for the shinyjs toggle()/show()/hide() functions. Whenever you need to conditionally show something where the condition is not a simple javascript expression of an input, it's easy to use these functions instead of a conditionalPanel().
In order to use these functions, you need to have some way to specify the element you want to hide/show (in this case, the mainPanel()). The easist way to do this is to just wrap the entire panel in a div with an id. So define the panel like mainPanel(div(id = "mainpanel", ...)) and voila, there's an id to your panel, and now you can call shinyjs::show("mainpanel") or hide() whenever you want in the server code.
What you are trying to do is not really possible the way you are trying to do it (the server and client are in different environments and don't share variables). You will need to explicitly pass the value from server to client, and there are different approaches to doing that. One way:
library(shiny)
runApp(list(ui = fluidPage(
conditionalPanel(condition='output.bool',
HTML("Hello world")),
actionButton("btn","Press me to toggle")
),
server = function(input, output, session) {
value=TRUE
output$bool <- eventReactive(input$btn,{
value
})
outputOptions(output,"bool",suspendWhenHidden=FALSE)
observeEvent(input$btn,
value <<- !value
)
}))
There are probably better approaches. Hope this helps
Note: After coming up with the answer I reworded the question to make if clearer.
Sometimes in a shiny app. I want to make use of a value selected by the user for a widget, as well as the previous value selected for that same widget. This could apply to reactive values derived from user input, where I want the old and the new value.
The problem is that if I try to save the value of a widget, then the variable containing that value has to be reactive or it will not update every time the widget changes. But, if I save the the value in a reactive context it will always give me the current value, not the previous one.
How can I save the previous value of a widget, but still have it update every time the user changes the widget?
Is there a way that does not require the use of an actionButton every time the user changes things? Avoiding an actionButton can be desirable with adding one is otherwise unnecessary and creates excess clicking for the user.
Seeing as the session flush event method seems to be broken for this purpose, here is an alternative way to do it using an observeEvent construct and a reactive variable.
library(shiny)
ui <- fluidPage(
h1("Memory"),
sidebarLayout(
sidebarPanel(
numericInput("val", "Next Value", 10)
),
mainPanel(
verbatimTextOutput("curval"),
verbatimTextOutput("lstval")
)
)
)
server <- function(input,output,session) {
rv <- reactiveValues(lstval=0,curval=0)
observeEvent(input$val, {rv$lstval <- rv$curval; rv$curval <- input$val})
curre <- reactive({req(input$val); input$val; rv$curval})
lstre <- reactive({req(input$val); input$val; rv$lstval})
output$curval <- renderPrint({sprintf("cur:%d",curre())})
output$lstval <- renderPrint({sprintf("lst:%d",lstre())})
}
options(shiny.reactlog = TRUE)
shinyApp(ui, server)
Yielding:
Update This answer was posted before the advent of the reactiveValues/observeEvent model in shiny. I think that #MikeWise 's answer is the better way to do this.
After some playing around this is what I came up with. The ui.r is nothing special
ui.r
library(shiny)
ui <- shinyUI(fluidPage(
sidebarLayout(
sidebarPanel(
selectizeInput(inputId="XX", label="Choose a letter",choices=letters[1:5])
),
mainPanel(
textOutput("Current"),
textOutput("old")
)
)
))
"Current" will display the current selection and "old" displays the previous selection.
In the server.r I made use of three key functions: reactiveValues, isolate and session$onFlush.
server.r
library(shiny)
server <- function(input, output,session) {
Values<-reactiveValues(old="Start")
session$onFlush(once=FALSE, function(){
isolate({ Values$old<-input$XX })
})
output$Current <- renderText({paste("Current:",input$XX)})
output$old <- renderText({ paste("Old:",Values$old) })
}
The server.r works like this.
First, Values$old is created using the reactiveValues function. I gave it the value "Start" to make it clear what was happening on load up.
Then I added a session$onFlush function. Note that I have session as an argument in my server function. This will run every time that shiny flushes the reactive system - such as when the selectizeInput is changed by the user. What is important is that it will run before input$XX gets a new value - so the value has changed at the selectizeInput but not at XX.
Inside the session$onFlush I then assign the outgoing value of XX to Values$old. This is done inside an isolate() as this will prevent any problems with input$XX gets updated with the new values. I can then use input$XX and Values$old in the renderText() functions.
I am new to Shiny and trying to build a more accessible input and output for a function I built. I am giving this to people that don't run R so trying to build something that runs my functions in the background and then spits out the answer.
I am having some trouble getting everything in the way that I want it unfortunately and dealing with a bunch of errors. However, here is my more pointed question:
The actual function that I want to run takes a name (in quotations as "Last,First") and a number.
PredH("Last,First",650)
So I want a shiny application that takes a name input and a number input that then runs this program and then spits back out a data table with my answer. So a couple of questions.
How do I get it in the right form to input into my equation on the server side script, do I need to return it in the function so it can be accessed using a function$table type access? (Right now I am just printing using cat() function in the console for the function but know that may not be usable for this type of application.
I want to return a dataframe that can be gotten at PredH14$table. How do I go about building that shiny?
Here is my code so far:
UI:
library(shiny)
shinyUI(pageWithSidebar(
# Application title
headerPanel("Miles Per Gallon"),
# Sidebar with controls to select the variable to plot against mpg
# and to specify whether outliers should be included
sidebarPanel(
textInput("playername", "Player Name (Last,First):", "Patch,Trevor"),
radioButtons("type", "Type:",
list("Pitcher" = "P",
"Hitter" = "H"
)),
numericInput("PAIP", "PA/IP:", 550),
submitButton("Run Comparables")
),
mainPanel(
textOutput("name")
)
Server:
library(shiny)
shinyServer(function(input, output) {
sliderValues <- reactive({
data.frame(
Name = c("name", "PA"),
Value = c(as.character(playername),
PAIP),
stringsAsFactors=FALSE)
})
name=input[1,2]
PAIP=input[2,2]
testing <- function(name,PAIP){
a=paste(name,PAIP)
return(a) }
output$name=renderText(testing$a)
})
I am not quite sure I understood your question 100% but I clearly see you are wondering how to pass the input of the UI into the server and maybe, the other way back.
In your server code, clearly you are not getting any input from the UI. Basically you have created three input variables in your ui.R:
1. input$playername
2. input$type
3. input$PAIP
And one output:
1. output$name
Just let you know, the function sliderValues <- reactive(..) is called every time there is any input from the input... like people click the dropdown list or people modifies words in the text box.
You can even get started without the submit button just to get started. But the existence of the submit button actually makes everything easier. Create a submit button for an input form. Forms that include a submit button do not automatically update their outputs when inputs change, rather they wait until the user explicitly clicks the submit button.
So you can put your code in a way similar like this:
# server.R
library(shiny)
shinyServer(function(input, output) {
sliderValues <- reactive({
result <- ... input$playername ... input$type ... input$PAIP
return(result)
})
output$name <- renderPlot/renderText (... sliderValues...)
})
# ui.R
library(shiny)
shinyUI(pageWithSidebar(
headerPanel("Miles Per Gallon"),
sidebarPanel(
textInput("playername" ... ),
radioButtons("type" ... ),
numericInput("PAIP" ... ),
submitButton("...")
),
mainPanel(
textOutput/plotOutput...("name")
)
))
In the end, check out the shiny example that might be what you want.
library(shiny)
runExample('07_widgets')