Selecting many items from the list in R - r

Question

I created an application in Shiny where I would like to choose multiple items from the drop-down menu. Unfortunately, I don't know how to make items on the list reduce after a given menu selection. By which all lines merge into a whole. what should I add in the code so that each model is a separate line. Below I put a picture with charts.
My code:
library(shiny)
library(plotly)
library(readxl)
library(shinyWidgets)
library(shinydashboard)
library(shinyjs)
library(DT)
df1 <- data.frame(Month = rep(month.abb[1:12],10,replace = TRUE), Model = paste0('Ferrari ', rep(LETTERS[1:10], each = 12)),
Value = sample(c(0:300),120, replace = T),
Car = rep('Ferrari', 10,each = 12), Year = rep(2019:2020, each = 60),Country = rep(c("USA","DE"), each = 12, times = 5), stringsAsFactors = F)
df2 <- data.frame(Month = rep(month.abb[1:12],10,replace = TRUE), Model = paste0('Porsche ', rep(LETTERS[1:10], each = 12)),
Value = sample(c(0:300),120, replace = T),
Car = rep('Porsche', 10,each = 12), Year = rep(2019:2020, each = 60), Country = rep(c("USA","DE"), each = 12, times = 5),stringsAsFactors = F)
data <-rbind(df1, df2)
ui <- fluidPage(
titlePanel("Test"),
sidebarLayout(
sidebarPanel( width = 3,
uiOutput("category1"),
uiOutput("category2"),
uiOutput("category3"),
uiOutput("category4")),
mainPanel(
tabsetPanel(type = "tabs",
tabPanel("Plot", plotlyOutput("plot", height = 550,width = 1000))
)
)
)
)
server <- function(input, output,session) {
output$category1 <- renderUI({
selectInput('cat1', 'Choose year:', multiple = T, selected = NULL, choices = sort(as.numeric(unique(data$Year))))
})
df_subset <- eventReactive(input$cat1,{
if(input$cat1=="All") {df_subset <- data}
else{df_subset <- data[data$Year == input$cat1,]}
})
df_subset1 <- reactive({
if(is.null(input$cat2)){df_subset()} else {df_subset()[df_subset()$Country %in% input$cat2,]}
})
output$category2 <- renderUI({
selectInput('cat2', 'Choose country:', choices = sort(as.character(unique(df_subset()$Country))), multiple = T, selected = NULL)
})
df_subset2 <- reactive({
if(is.null(input$cat3)){df_subset1()} else {df_subset1()[df_subset1()$Car %in% input$cat3,]}
})
output$category3 <- renderUI({
selectInput('cat3', 'Choose car:', choices = sort(as.character(unique(df_subset1()$Car))), multiple = F, selected = NULL)
})
df_subset3 <- reactive({
if(is.null(input$cat4)){df_subset2()} else {df_subset2()[df_subset2()$Model %in% input$cat4,]}
})
output$category4 <- renderUI({
pickerInput('cat4', 'Choose model:', choices = sort(as.character(unique(df_subset2()$Model))), multiple = TRUE, selected = NULL)
})
output$plot <- renderPlotly({
xform <- list(categoryorder = "array",
categoryarray = df_subset3()$Month,
title = " ",
nticks=12)
plot_ly(data=df_subset3(), x=~Month, y = ~Value, type = 'scatter', mode = 'lines', name = 'Value') %>%
layout(title = " ",xaxis = xform) %>%
layout(legend = list(orientation = 'h', xanchor = "center", y=1.1, x=0.5))
})
}
shinyApp(ui, server)

Answer 1

To display each model as a separate line on the plot, you can assign the Model column of your dataset to the color parameter of plot_ly this way:
plot_ly( data = df_subset3(), x = ~Month, y = ~Value, color = ~Model, ...)