R Shiny run function on file upload - r

Question

I have a Shiny App that takes a text file from FileInput , processed it and sets a few variables / data frames which are then displayed in InfoBoxOutputs .
I know I can currently process the file in the output of the server function for elements eg a Datable like in my code below, but this doesnt seem to update the InfoBoxOutputs even though the variables used are set during the Seed() function (they are definetly set ) that runs for the Datatable output.
So is there a way to run my Seed() function to process all the data at once so that all my elements an use the processed data or do I have to rerun the function foreach element ?
#Initialize variables which will later be set in Seed()
mostwanted_variable <- NULL
key_vaiable <- NULL
ui <- dashboardPage(skin = "blue",
dashboardHeader( title = "Text Check"),
dashboardSidebar(
fileInput("file1", "Upload File",
multiple = FALSE,
accept = c( ".txt"))
),
dashboardBody(
tabItems(
tabItem(tabName = "statistics",
fluidRow(
infoBoxOutput("info1"),
infoBoxOutput("info2")
),
# infoBoxes with fill=TRUE
fluidRow(
DT::dataTableOutput("mytable")
)
)
)
)
)
server <- function(input, output) {
# Main List Output
output$mytable = DT::renderDataTable({
file <- input$file1
ext <- tools::file_ext(file$datapath)
req(file)
validate(need(ext == ".txt", "Please upload a text file"))
## Processes Text File and sets many variables & frames
Seed(file$datapath)
## Select maindatasource which is set in the Seed function
maindatasource
})
# Info Box 1
# uses variable set during Seed function
output$info1 <- renderInfoBox({
infoBox(
"Key", key_variable, icon = icon("user-secret"),
color = "aqua" , fill = TRUE
)
})
# Info Box 2
# uses variable set during Seed function
output$info2 <- renderInfoBox({
infoBox(
"Most Wanted", mostwanted_variable, icon = icon("earlybirds"),
color = "aqua"
)
})
}

Answer 1

You could set reactiveValues in the Seed() function, that would be used to update info bpxes.
library(shiny)
library(shinydashboard)
ui <- dashboardPage(
skin = "blue",
dashboardHeader(title = "Text Check"),
dashboardSidebar(fileInput(
"file1",
"Upload File",
multiple = FALSE,
accept = c(".txt")
)),
dashboardBody(
fluidRow(infoBoxOutput("info1"),
nfoBoxOutput("info2")),
fluidRow(DT::dataTableOutput("mytable"))
)
)
server <- function(input, output) {
rv <- reactiveValues(
mostwanted_variable = NULL,
key_variable = NULL)
Seed <- function(filename) {
rv$mostwanted_variable <- "a"
rv$key_variable <- 123
return(data.frame(
main = c(1, 2),
data = c("a", "b"),
source = c(3, 4)
))
}
# Main List Output
output$mytable = DT::renderDataTable({
file <- input$file1
ext <- tools::file_ext(file$datapath)
req(file)
validate(need(ext == "txt", "Please upload a text file"))
## Processes Text File and sets many variables & frames
maindatasource <- Seed(file$datapath)
})
# Info Box 1
# uses variable set during Seed function
output$info1 <- renderInfoBox({
infoBox(
"Key",
rv$key_variable,
icon = icon("user-secret"),
color = "aqua" ,
fill = TRUE
)
})
# Info Box 2
# uses variable set during Seed function
output$info2 <- renderInfoBox({
infoBox(
"Most Wanted",
rv$mostwanted_variable,
icon = icon("earlybirds"),
color = "aqua"
)
})
}
shinyApp(ui, server)