Selected output elements not pass to rmd document in downloadHandler

Question

I'd like to create a pdf document with the actual output of my dashboard and some additional elements:

1. titlePanel(title="My Map Dashboard")
2. inputId = "Dates selection"
3. output$myplot
4. output$map

I'll think in making something like downloadButton("report", "Generate report") and set up parameters (params) to pass to Rmd document take my target elements for the pdf report creation, but not work yet and the output error is:

Listening on http://127.0.0.1:4368
Warning: Error in $.shinyoutput: Reading from shinyoutput object is not allowed.
  [No stack trace available]

In my example:

library(leaflet)
library(leaflet.providers)
library(ggplot2)
library(shinythemes)
library(sf)
library(lubridate)
library(dplyr)
library(rmarkdown)
library(rgdal)


# get AOI
download.file(
  "https://github.com/Leprechault/trash/raw/main/stands_example.zip",
  zip_path <- tempfile(fileext = ".zip")
)
unzip(zip_path, exdir = tempdir())

# Open the files
setwd(tempdir())
stands_extent <- readOGR(".", "stands_target") # Border
stands_ds <- read.csv("pred_target_stands.csv", sep=";") # Data set
stands_ds <- stands_ds %>%
  mutate(DATA_S2 = ymd(DATA_S2))

# Create the shiny dash
ui <- fluidPage(
  theme = shinytheme("cosmo"),
  titlePanel(title="My Map Dashboard"),  
  sidebarLayout(
    sidebarPanel(
      selectInput(inputId = "selectedvariable0",
                  label = "Type", 
                  choices = c(unique(stands_ds$PEST)),selected = TRUE ), 
      selectInput(inputId = "selectedvariable1",
                  label = "Date", 
                  choices = c(unique(stands_ds$DATA_S)),selected = TRUE ), 
      selectInput(inputId = "selectedvariable2",
                  label = "Project", 
                  choices = c(unique(stands_ds$PROJETO)),selected = TRUE ),
      selectInput(inputId = "selectedvariable3",
                  label = "Stand", 
                  choices = c(unique(stands_ds$CD_TALHAO)),selected = TRUE),
      selectInput(inputId = "selectedvariable4",
                  label = "Unique ID", 
                  choices = c(unique(stands_ds$ID_UNIQUE)),selected = TRUE),
      downloadButton("report", "Generate report")
    ),
    mainPanel(
      textOutput("idSaida"),
      fluidRow(
        splitLayout(plotOutput("myplot"))),
      dateInput(inputId = "Dates selection", label = "Time"),
      leafletOutput("map") 
    )
  )
)
server <- function(input, output){
  
  currentvariable0 <- reactive({input$selectedvariable0})
  currentvariable1 <- reactive({input$selectedvariable1})
  currentvariable2 <- reactive({input$selectedvariable2})
  currentvariable3 <- reactive({input$selectedvariable3})
  currentvariable4 <- reactive({input$selectedvariable4})
  
  output$myplot <- renderPlot({
    
    #Subset stand
    stands_sel <- subset(stands_extent, stands_extent@data$ID_UNIQUE==currentvariable4())
    
    #Subset for input$var and assign this subset to new object, "fbar"
    ds_sel<- stands_ds[stands_ds$ID_UNIQUE==currentvariable4(),]
    
    #Create a map
    polys <- st_as_sf(stands_sel)
    ggplot() +
      geom_sf(data=polys) +
      geom_point(data=ds_sel,
                 aes(x=X, y=Y), color="red") +
      xlab("Longitude") + ylab("Latitude") +
      coord_sf() +
      theme_bw() +
      theme(text = element_text(size=10)) 
  })
  
  output$map <- renderLeaflet({
    
    stands_actual<-stands_ds[stands_ds$ID_UNIQUE==currentvariable4(),]
    lng <- mean(stands_actual$X)
    lat <- mean(stands_actual$Y)
    
    leaflet() %>%
      setView(lng = lng, lat = lat, zoom=17) %>%
      addProviderTiles(providers$Esri.WorldImagery) %>%                   
      addMarkers(lng=stands_actual$X, lat=stands_actual$Y, popup="Location")
    
  })   
  output$report <- downloadHandler(

    filename = "report.pdf",
    content = function(file) {

      tempReport <- file.path(tempdir(), "report.Rmd")
      file.copy("report.Rmd", tempReport, overwrite = TRUE)
      
      # Set up parameters to pass to Rmd document
      params <- list(n = c(title="My Map Dashboard", output$myplot,output$map))
      
      # Knit the document, passing in the `params` list, and eval it in a
      # child of the global environment (this isolates the code in the document
      rmarkdown::render(tempReport, output_file = file,
                        params = params,
                        envir = new.env(parent = globalenv())
      )
      }
    )
}
shinyApp(ui, server)
##

Please, any ideas or another way for my problem?

Thanks in advance!!