R Shiny ObserveEvent with multiple inputs - r

Question

The below code is working, but I need to enhance it by observing multiple inputs.
I need a multiple observeEvent on input$dateinput which selects the xlsx file to open and input$myfilter which checks if the user wants to apply a specific filter to the data.
but when I change
observeEvent(input$dateinput,... to:
observeEvent( c(input$dateinput, input$myfilter),{
The app crashes with Warning: Error in file: invalid 'description' argument [No stack trace available]
The code otherwise runs fine. Any help? thanks
full code : EDIT: THIS IS NOW REPRODUCIBLE AND DOES NOT REQUIRE ANY EXCEL FILE
library(shiny)
library(shinyWidgets)
library(openxlsx)
opendir <- function(dir = getwd()){
if (.Platform['OS.type'] == "windows"){
shell.exec(dir)
} else {
system(paste(Sys.getenv("R_BROWSER"), dir))
}
}
ui <- fluidPage(
sidebarPanel(
uiOutput("gpui")
),
mainPanel(
titlePanel("test app"),
br(),
checkboxInput("myfilter", label = "Filter all unnecessary (71, 46, 44) documents", value = TRUE),
br(),
tableOutput("datatable")
)
)
server <- function(input, output, session) {
rvalues <- reactiveValues()
rvalues$listfiles <- list.files(pattern=".xlsx")
observeEvent(input$refresh, {
print(input$dateinput)
session$reload()
})
observeEvent(input$openfolder, {
opendir()
})
output$gpui <- renderUI({
tagList(
actionButton("openfolder", "Open Data Folder"),
actionButton("refresh", "Refresh data folder"),
pickerInput("dateinput","Choose the date", choices=isolate(rvalues$listfiles), options = list(`actions-box` = TRUE),multiple = F)
)
})
observeEvent(input$myfilter,{
print("myfilter")
})
observeEvent( input$dateinput ,{
print(input$dateinput)
print("selecteddata")
cols <- c("Purchasing.Document", "Net.Order.Value", "Currency", "G/L.Account",
"Short.Text",
"Requisitioner", "Release.indicator", "Deletion.indicator")
seldata <- read.xlsx(input$dateinput)
print(nrow(seldata))
seldata <- seldata[,cols]
myfilter <- substr(seldata$Purchasing.Document,1,2) %in% c("71", "46", "44")
if(input$myfilter) {
rvalues$data <- seldata[myfilter,]
}
rvalues$data <- seldata
})
output$datatable <- renderTable(
rvalues$data,
striped = T,
spacing = 's'
)
}
shinyApp(ui, server)

Answer 1

For multiple observes in observeEvent() wrap them in curly brackets without commas, just as regular code.
Try:
shiny::observeEvent(
eventExpr = {
input$dataInput
input$myFilter
},
handlerExpr = {
# You code to run
}
)
In my experience it can be safer to wrap complex observeEvent expressions (handlerExpr) in isolate({}) to suppress any undesired reactivity.

Answer 2

When your observer reacts to input$myfilter, it is triggered at the startup. And input$dateinput is NULL. So you get this error:
> openxlsx::read.xlsx(NULL)
Error in file(description = xlsxFile) : argument 'description' incorrect