add blank space on shiny slider - css

I have a shiny app where I am using a shinyWidgets::sliderTextInput() slider to select a numeric value, but the scale is a bunch of consecutive numbers, then one quite far away. (In my case, it's select a year out of 2000-2010, or 2050).
Is there a way to use css to add visual space between two specific ticks on a shiny slider? In the reprex below, I use the default histogram shiny to select number of bins out of c(1:30,50). Here, I'd like the slider bar to show ticks 1:30 evenly spaced, then some sort of visual gap between the last two ticks (30 and 50) just to visually make it clear those are not consecutive. That space doesn't have to be 20 units long (the actual numerical difference), just an extra bit to help the user notice the difference.
I don't want to add in a "NA" to my selection vector because I don't want the space between those ticks to be selectable.
Based on Chrome web inspector, I know it has to do with object class irs-grid and irs-grid-pol, but I can't figure out how to change the spacing of those.
Thanks in advance!
reprex:
library(shiny)
# Define UI for application that draws a histogram
ui <- fluidPage(
# Application title
titlePanel("Old Faithful Geyser Data"),
# Sidebar with a slider input for number of bins
sidebarLayout(
sidebarPanel(
shinyWidgets::sliderTextInput(
inputId = "bins",
label = "Number of bins:",
selected = 20,
choices = c(1:30, 50),
grid = TRUE
),
),
# Show a plot of the generated distribution
mainPanel(
plotOutput("distPlot")
)
)
)
# Define server logic required to draw a histogram
server <- function(input, output) {
output$distPlot <- renderPlot({
# generate bins based on input$bins from ui.R
x <- faithful[, 2]
bins <- seq(min(x), max(x), length.out = input$bins + 1)
# draw the histogram with the specified number of bins
hist(x, breaks = bins, col = 'darkgray', border = 'white')
})
}
# Run the application
shinyApp(ui = ui, server = server)

Related

How can I trigger an output when a value changes in a different output?

I have an output that takes user input to select which of a number of calculations to use and results in 5 numbers. That output pushes out the results of this and other calculations as an HTML table. The individual calculations are not particularly complicated, but user selections choose which of many approaches they are using, so I don't really want to replicate all that code in other outputs that are going to use just those 5 numbers.
My thought was to use the double-arrow to make those numbers available to the other outputs (in my case some plots). My goal is to generate graphs from numbers already generated in a different output, however that gets accomplished. I am not attached to the approach below, it is just where I am right now.
I ran into a number of problems just using <<- and tried a lot of things to get it to work. I won't complicate this further with all the things I tried and the problems they created.
The MRE below replicates this by calculating a number in one output that is then to be used in another output. If you enter different numbers of bins, the second output is never triggered to update to the new number. For this MRE I could of course directly use the user input to calculate that number but that is what I am trying to avoid in the real app. I also don't want to use a "Go!" button if I can avoid it since part of the fun is watching how things change in response to your various selections.
# Define UI for application that draws a histogram
ui <- fluidPage(
# Application title
titlePanel("Old Faithful Geyser Data"),
# Sidebar with a slider input for number of bins
sidebarLayout(
sidebarPanel(
numericInput("bins",
"Number of bins:",
min = 1,
max = 50,
value = 30)
),
# Show a plot of the generated distribution
mainPanel(
plotOutput("distPlot"),
textOutput("binnum")
)
)
)
# Define server logic required to draw a histogram
server <- function(input, output) {
a_number<-0
output$distPlot <- renderPlot({
# generate bins based on input$bins from ui.R
x <- faithful[, 2]
bins <- seq(min(x), max(x), length.out = input$bins + 1)
a_number<<-bins[2]/5}
# draw the histogram with the specified number of bins
hist(x, breaks = bins, col = 'darkgray', border = 'white')
})
output$binnum<-renderText({
a_number
})
}
# Run the application
shinyApp(ui = ui, server = server)
Could you just treat bins and a_number as reactive?
# Define UI for application that draws a histogram
ui <- fluidPage(
# Application title
titlePanel("Old Faithful Geyser Data"),
# Sidebar with a slider input for number of bins
sidebarLayout(
sidebarPanel(
numericInput("bins",
"Number of bins:",
min = 1,
max = 50,
value = 30)
),
# Show a plot of the generated distribution
mainPanel(
plotOutput("distPlot"),
textOutput("binnum")
)
)
)
# Define server logic required to draw a histogram
server <- function(input, output) {
# a_number<-0
# generate bins based on input$bins from ui.R
data(faithful)
x <- faithful[, 2]
bins <- reactive({
seq(min(x), max(x), length.out = input$bins + 1)
})
a_number <- reactive({
req(bins())
-bins()[2]/5
})
output$distPlot <- renderPlot({
# draw the histogram with the specified number of bins
hist(x, breaks = bins(), col = 'darkgray', border = 'white', xlab = paste0("a = ", -bins()[2]/5))
})
output$binnum<-renderText({
a_number()
})
}
# Run the application
shinyApp(ui = ui, server = server)

Increasing margins for base plot in RShiny (arguments to par() are not respected)

I am having issues with a Shiny App such that the text labels are being cut off. If I were performing this plotting in R, I would adjust the margins of the plotting area using par(mar = c(10,10,10,10)), or other adjustments.
However, when I attempt to adjust the margins using par() within a shiny app no change takes effect. Here is a sample shiny app where I attempt to adjust the margins without success:
server.R
library(shiny)
shinyServer(function(input, output) {
output$distPlot <- renderPlot({
x <- faithful[, 2]
bins <- seq(min(x), max(x), length.out = input$bins + 1)
par(mar = c(10,10,10,10))
hist(x, breaks = bins, col = 'darkgray', border = 'white', main = "Obsequious people are usually not being genuine; they resort to flattery and other fawning ways to stay in the good graces of authority figures. An obsequious person can be called a bootlicker, a brownnoser or a toady.")
})
})
ui.R
library(shiny)
# Define UI for application that draws a histogram
shinyUI(fluidPage(
# Application title
titlePanel("Old Faithful Geyser Data"),
# Sidebar with a slider input for number of bins
sidebarLayout(
sidebarPanel(
sliderInput("bins",
"Number of bins:",
min = 1,
max = 50,
value = 30)
),
# Show a plot of the generated distribution
mainPanel(
plotOutput("distPlot")
)
)
))
Is it possible to use par() to define a plotting area for a shiny app?

Read R code from a file (i.e. source) in a shiny App

I want to modularise my shiny app code, by moving parts of the code in separate files. I then include the content of the file with a call to the source function: source("./www/some_code.R", local = TRUE)
It works well except for an undesired effect: the word TRUE is added just below the insert.
Could you help me understand why this happen and how I can remove this undesired text?
For a reproducible example,
create app.R:
#
# Find out more about building applications with Shiny here:
#
# http://shiny.rstudio.com/
#
library(shiny)
# Define UI for application that draws a histogram
ui <- fluidPage(
# Application title
titlePanel("Old Faithful Geyser Data"),
# Sidebar with a slider input for number of bins
sidebarLayout(
sidebarPanel(
source("./www/slider.R", local = TRUE)
),
# Show a plot of the generated distribution
mainPanel(
plotOutput("distPlot")
)
)
)
# Define server logic required to draw a histogram
server <- function(input, output) {
output$distPlot <- renderPlot({
# generate bins based on input$bins from ui.R
x <- faithful[, 2]
bins <- seq(min(x), max(x), length.out = input$bins + 1)
# draw the histogram with the specified number of bins
hist(x, breaks = bins, col = 'darkgray', border = 'white')
})
}
# Run the application
shinyApp(ui = ui, server = server)
and in the www folder the slider.R:
sliderInput("bins",
"Number of bins:",
min = 1,
max = 50,
value = 30)
Just when I posted this, I saw a link to this which answer the question: displaying TRUE when shiny files are split into different folders
I thought that I did my research though... Should I delete the whole thread?

Make Shinyapp use new input across sessions

I´m using a shinyapp on an opensource shiny-server to display a dashboard on multiple devices. I want to give the opportunity to change the plots on all dashboards from a local PC.
If the input is altered in any session, all sessions should update their plots to this new input. How do i do this? Can i save the input in a global variable?
library(shiny)
# Define UI for application that draws a histogram
ui <- fluidPage(
# Application title
titlePanel("Old Faithful Geyser Data"),
# Sidebar with a slider input for number of bins
sidebarLayout(
sidebarPanel(
sliderInput("bins",
"Number of bins:",
min = 1,
max = 50,
value = 30)
),
# Show a plot of the generated distribution
mainPanel(
plotOutput("distPlot")
)
)
)
# Define server logic required to draw a histogram
server <- function(input, output) {
observe({
invalidateLater(10000)
# generate bins based on input$bins from ui.R
x <- faithful[, 2]
bins <- seq(min(x), max(x), length.out = input$bins + 1)
# draw the histogram with the specified number of bins
p<<- hist(x, breaks = bins, col = 'darkgray', border = 'white')
})
output$distPlot <- renderPlot({print(p)})
}
# Run the application
shinyApp(ui = ui, server = server)
You can initiate an reactiveValue in the global file and use this instead up the original input
In principal all objects initiated in the global file are shared over sessions.
Example
**UI **
library(shiny)
# Define UI for application that plots random distributions
shinyUI(pageWithSidebar(
# Application title
headerPanel("It's Alive!"),
# Sidebar with a slider input for number of observations
sidebarPanel(
sliderInput("bins",
"Number of bins:",
min = 1,
max = 50,
value = 30)
),
# Show a plot of the generated distribution
mainPanel(
plotOutput("distPlot", height=250)
)
))
**Server **
library(shiny)
# Define server logic required to draw a histogram
shinyServer(function(input, output) {
# Expression that generates a histogram. The expression is
# wrapped in a call to renderPlot to indicate that:
#
# 1) It is "reactive" and therefore should be automatically
# re-executed when inputs change
# 2) Its output type is a plot
observe({
RV$bins = input$bins
})
output$distPlot <- renderPlot({
x <- faithful[, 2] # Old Faithful Geyser data
bins <- seq(min(x), max(x), length.out = RV$bins + 1)
# draw the histogram with the specified number of bins
hist(x, breaks = bins, col = 'darkgray', border = 'white')
})
})
** Global **
RV <- reactiveValues(bins = 10)
When a user changes the number of bins the histogram will changes for all users but not the slider.
Hope this helps!!

Error in y axis label in shiny app using cairo

so I wrote a shiny app for importing data and plotting it using ggplot2. If I use cairo for plotting
options(shiny.usecairo=T)
(should be active by default) plots are prettier but y axis label "Oxygen consumption" miss some parts.
Plot without cairo:
Plot with cairo:
Can someone point me towards a solution or have ideas what the mistake is?
Edit: here is a minimal example:
library(shiny)
library(ggplot2)
options(shiny.usecairo=T)
# Define UI for application that draws a histogram
ui <- fluidPage(
# Application title
titlePanel("Old Faithful Geyser Data"),
# Sidebar with a slider input for number of bins
sidebarLayout(
sidebarPanel(
sliderInput("bins",
"Number of bins:",
min = 1,
max = 50,
value = 30),
sliderInput("size",
"size:",
min = 0.1,
max = 40,
value = 15)
),
# Show a plot of the generated distribution
mainPanel(
plotOutput("distPlot")
)
)
)
# Define server logic required to draw a histogram
server <- function(input, output) {
res<- reactive({input$resolution})
output$distPlot <- renderPlot({
#refresh on
print(input$resolution)
# generate bins based on input$bins from ui.R
x <- faithful[, 2]
bins <- seq(min(x), max(x), length.out = input$bins + 1)
# draw the histogram with the specified number of bins
qplot(x, breaks = bins, col = 'darkgray', ylab = "Some long string to test for errors and see what is affected")+theme_classic(base_size=input$size)
})
}
# Run the application
shinyApp(ui = ui, server = server)
So, for me it looks like some characters get cut on the right.
Edit: I narrowed this down to my windows machine, can't see it on shinyapps.io and local linux server anymore. Probably not so relevant then, since the error is only happening during development.

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