Shiny dashboard and leaflet using selectInput - r

Question

i am trying to use shiny dashboard with leaflet package. I tried using "SelectInput" function in the dashboard to create reactive map based on the input selected(geoArea).However, i am not able to make the leaflet and the SelectInput connect with each other.
I also wanted to distinguish two groups in my dataset and plot it in leaflet/shiny (column name "up.and.down" has positive and negative values).In Base R i could do it using filter option from the tidyverse package and give distinct colour to each but however i am not sure how this works in Shinydashboard. Any help in regards will be much appreciated.
library(shiny)
library(shinydashboard)
library(shinydashboardPlus)
library(leaflet)
library(tidyverse)
datafile<- read.csv("/Users/prabeshkc/Desktop/stackoverflow data.csv")
`ui<- dashboardPage(
skin = "blue",
dashboardHeader(title = "Cluster Map"),
dashboardSidebar(
selectInput("Area",label = "Geo Area",
choices = datafile$geoArea)
),
dashboardBody(
fluidRow(box(width = 12,leafletOutput(outputId = "mymap")))
))`
`server <- function(input, output) {
data_input<-reactive({
datafile %>%
leaflet() %>%
addTiles() %>%
addMarkers(lng = datafile$lng,lat = datafile$lat)
})
data_input_ordered<-reactive({
data_input()[order(match(data_input)$geoArea)]
})`
`labels<- reactive({
paste("<p>", datafile$goals,"</p>"),
paste("<p>", datafile$achieved,"</p>")
})`
`output$mymap<- renderLeaflet(
datafile %>%
leaflet() %>%
addTiles() %>%
addCircleMarkers(lng = datafile$lng,lat = datafile$lat)
)
}
shinyApp(ui = ui, server = server)`

Answer 1

Try this one:
library(shiny)
library(shinydashboard)
library(shinydashboardPlus)
library(leaflet)
library(tidyverse)
datafile<-read.csv("/Users/prabeshkc/Desktop/stackoverflow data.csv") %>%
mutate(color=ifelse(up.and.down<0,"red","blue"))
ui<- dashboardPage(
skin = "blue",
dashboardHeader(title = "Cluster Map"),
dashboardSidebar(
selectInput("Area",label = "Geo Area",
choices = datafile$geoArea)
),
dashboardBody(
fluidRow(box(width = 12,leafletOutput(outputId = "mymap")))
))
server <- function(input, output) {
output$mymap<- renderLeaflet({
validate(need(datafile,"Add file"))
validate(need(input$Area,"Select Area"))
datafile %>%
filter(geoArea %in% input$Area) %>%
leaflet() %>%
addTiles() %>%
addCircleMarkers(lng = ~lng,lat = ~lat,color=~color,
popup = ~paste(paste0("Goals - ",goals),paste0("Achieved - ",achieved), sep="<br>"))
})
}
shinyApp(ui = ui, server = server)