How to solve "Input to asJSON(keep_vec_names=TRUE

shiny
1

Input to asJSON(keep_vec_names=TRUE) is a named vector. In a future version of jsonlite, this option will not be supported, and named vectors will be translated into arrays instead of objects. If you want JSON object output, please use a named list instead. See ?toJSON.
This problem happens when I run the plot at the end of the script, and I do not know how to solve it. Help?

library(shiny)
library(ggplot2)
library(caret)
library(shinyPredict)
library(ISLR2)

# Define server logic required to draw a histogram
function(input, output, session) {
  
  datasets <- list(AirPassengers = AirPassengers, CO2 = CO2, Formaldehyde = Formaldehyde, Indometh = Indometh, 
                   LifeCycleSavings = LifeCycleSavings, OrchardSprays = OrchardSprays, Theoph = Theoph, 
                   UKDriverDeaths = UKDriverDeaths, WWWusage = WWWusage, austres = austres,chickwts = chickwts,
                   esoph = esoph, faithful = faithful, islands = islands, lynx = lynx, nhtemp = nhtemp, precip = precip, randu = randu,
                   stack.loss = stack.loss, state.area = state.area, state.region = state.region, sunspots = sunspots, BJsales = BJsales,
                   ChickWeight = ChickWeight, HairEyeColor = HairEyeColor, InsectSprays = InsectSprays, Loblolly = Loblolly, PlantGrowth = PlantGrowth,
                   Titanic = Titanic, UKgas = UKgas, USPersonalExpenditure = USPersonalExpenditure, WorldPhones = WorldPhones, anscombe = anscombe, 
                   beaver1 = beaver1, co2 = co2, euro = euro, fdeaths = fdeaths, infert = infert, ldeaths = ldeaths, mdeaths = mdeaths,
                   nottem = nottem, presidenst = presidents, rivers = rivers, stackloss = stackloss, state.center = state.center, state.x77 = state.x77,
                   swiss = swiss, volcano = volcano, BJsales.lead = BJsales.lead, DNase = DNase, Harman23.cor = Harman23.cor, JohnsonJohnson = JohnsonJohnson, 
                   Nile = Nile, mtcars = mtcars, trees = trees)

  #output$pkgs <- renderPrint(.packages(all.available = TRUE))
  
  
 # output$dat <- renderPrint(data(package = "datasets")$results[ , "Item"])
  #print(trees)
 
  ds <- reactive( datasets[[input$inDs]] )
  
  observe(updateVarSelectInput(session, "inVar", data = ds()))
  observe(updateVarSelectInput(session, "inVar1", data = ds()))
  
 output$outData <- renderTable({ 
   var_char <- as.character(input$inVar)
    # deal with race conditions,  input$inVar might still include 
    # a column name from previously selected dataset
    req(var_char %in% names(ds()))
    ds()[1:12, var_char, drop = FALSE] 
  }, align = "l")
 
 output$outData1 <- renderTable({ 
   var_char1 <- as.character(input$inVar1)
   # deal with race conditions,  input$inVar might still include 
   # a column name from previously selected dataset
   req(var_char1 %in% names(ds()))
   ds()[1:12, var_char1, drop = FALSE] 
 }, align = "l")
  
 output$hist <- renderPlot({ + 
   ggplot(ds(), aes_string(input$inVar,input$inVar1)) + geom_histogram()
 })
2

When I do the code below, i get the error [object Object]

output$hist <- renderPlot({ + 
   ggplot(ds(), aes_string(as.character(input$inVar), as.character(input$inVar1))) + geom_histogram()
 })

However, this code below works very well

output$plot <- renderPlot({
   
   ggplot(ds(), aes_string(as.character(input$inVar), as.character(input$inVar1))) + geom_point()
 }, res = 96)
3

I understand what the problem is. When you plot a histogram, you need to provide one variable only not x and y