Updating checkbox value in Shiny - r

Question

I am trying to make a Shiny app that does the following:
1) Upload a file like this:
X Y
1 3
2 1
3 6
4 4
2) Press a Run button to add 2 to the file values by default, or multiplying by 2 if a box is checked,
3) Making a scatter plot out of the generated values.
My problems are (i) I need to check/uncheck the box and then press again the Run button to display the corresponding plot, and (ii) the checkbox comes back to on every time.
How could I update the plot when I check/uncheck the box without pressing the Run button?
I tried to place the observe() and updateCheckboxInput() function outside the eventReactive() block, but it does simply not work.
My code:
library(shiny)
library(ggplot2)
ui <- fluidPage(
fileInput(
inputId = "input_file",
label = "Choose an input file"
),
actionButton(
inputId = "run_button",
label = "Run"
),
checkboxInput(
inputId = "operation_button",
label = "multiply instead of summing",
value = FALSE
),
plotOutput(
outputId = "my_plot"
)
)
server <- function(input, output, session) {
my_data <- eventReactive(
input$run_button,
{
inFile <- input$input_file
if(is.null(inFile)){
return(NULL)
}
my_in <- read.table(inFile$datapath, header = T, sep = "\t")
my_function <- function(input, operation){
if(operation == "sum"){
input <- input + 2
}else if(operation == "multiply"){
input <- input * 2
}
return(input)
}
button_switch <- ifelse(input$operation_button == FALSE, "sum", "multiply")
observe(
{
updateCheckboxInput(session, "operation_button", "multiply instead of summing", value = button_switch)
}
)
my_in <- my_function(my_in, button_switch)
}
)
output$my_plot <- renderPlot(
{
my_df <- my_data()
ggplot(my_df, aes(x=X, y=Y)) +
geom_point()
}
)
}
shinyApp(ui = ui, server = server)

Answer 1

You could make the eventReactive() dependent on multiple inputs:
my_data <- eventReactive(c(input$run_button, input$operation_button),...)