multiple conditions observeEvent - R Shiny

Question

I am trying to do a Shiny app with an interactive map displaying marine animal tags. Currently, I have three possible inputs : (1) The tag numbers, (2) the size of the animals and (3) the month I want to display. For the size it works easily as I update the tag number input, but I am stuck with the months ... I already tried with :

observeEvent({input$selected_tag
input$selected_month},{...

and by including the inputs inside a reactive expression but an error occur :

Avis : Error in sum: 'type' (list) de l'argument incorrect

Would you have an idea please ? Or are my inputs poorly defined (cf the error) ? Here is a reprex and a sample of my data https://github.com/rcanet/ABFT_migration/blob/main/test_file.csv (line with #### What happens when you click on a tag ? ####):

library(shiny)
library(leaflet)
library(lubridate)

#### Data loading ####
### Tags table

tag_data <- read.csv("test_file.csv", header = TRUE, sep=",",dec=".")
tag_data$tag <- as.factor(tag_data$tag)
id_tag <- levels(tag_data$tag)
tag_data$date = ymd(tag_data$date)

## Definition of the applicable filters
filtering_option <- c("Size", "Months")

## Definition of the seasons
months_tag <- c("January", "February", "March", "April", 
                "May", "June", "July", "August", "September",
                "October", "November", "December")

################################################################################

#### Shiny app UI ####
ui <- fluidPage(
  tabsetPanel(
               column(2, selectizeInput("selected_tag", "Which tags do you want to see ?", 
                                        choices = id_tag, multiple = TRUE),                      
                      hr(), ## Filters
                      p(strong("Which filter do you want to use ?")),
                      checkboxInput("filter_size", "Size"),
                      conditionalPanel(condition = "input.filter_size == 1",
                                       sliderInput("slider_size", "Choose a size range (in cm)",
                                                   value = c(min(unique(tag_data$size_at_tagging)), 
                                                             max(unique(tag_data$size_at_tagging))),
                                                   min = min(unique(tag_data$size_at_tagging)), 
                                                   max = max(unique(tag_data$size_at_tagging)))
                      ),
                      checkboxInput("filter_month", "Months"),
                      conditionalPanel(condition = "input.filter_month == 1",
                                       selectizeInput("selected_month", 
                                                      "Which months do you want to see ?",
                                                      choices = months_tag,
                                                      selected = months_tag[1],
                                                      multiple = TRUE)),
                      actionButton("reset_button", "Reset"),
                      textOutput("test_debbuging")),
               column(10, leafletOutput("map_tag", height = "850px"))
  ))

################################################################################

#### Shiny app server ####
server <- function(input, output, session) {

  observeEvent(input$selected_month, {cat(input$selected_month, "\n")})
  observeEvent(input$selected_tag, {cat(input$selected_tag)})
  
}

shinyApp(ui, server)

'''

Answer 1

So after a few tries, I finally figure it out. The bug indeed was in the leaflet. The problem lied in the label argument of addAwesomeMarkers. Change "label" by "popout" and it should be okay ! (As I had to reduce my reprex the error is no longer in my initial post)

Answer 2

you can define a list of desired input parameters:

toListen <- reactive({
   list(input$selected_tag, input$selected_month)
})

and then use your reactive list in combination with your observeEvent:

observeEvent(toListen(),{...})