Make Shinyapp use new input across sessions - r

Question

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)

Answer 1

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!!