R and Shiny: object not found - r

Question

EDITED to include full UI and sample data
I did read the other StackOverflow qs on this issue, but none seemed to address the cause of my error.
When the app loads, I get "error object [name of district I've selected] not found" for the District (inputID = "d"). I know it must be an issue with the subsetting reactive in the server, but I've tried everything (loading the data in the server, removing the vector from the filter function, changing the data type of the variables).
I also took this code from another Shiny App I built, which works. I can't see any differences between the two, besides that one is geom_point() and this is geom_col() so again, not sure what is going on.
Thanks!
Sample data:
sample <- sample_n(pop, 10)
dput(sample)
structure(list(GazID = c(NA, NA, "13872", NA, "13610", "13985",
"13984", "13434", "13428", "13631"), Province = c("Niolandskaia",
"Kaluzhskaia", "Iaroslavskaia", "Vyborgskaia", "Moskovskaia",
"Volynskaia", "Volynskaia", "Orenburgskaia", "Orenburgskaia",
"Arkhangel'skaia"), District = c(NA, "Suhinichinbezuezdniigorod",
"Romanov", NA, "Zvenigorod", "Kovel", "Lutsk", "Ufa", "Orenburg",
"Mezen"), TotalPop = c(NA, NA, 104104, NA, 71746, 103381, 102779,
93145, 62740, 26796), Male = c(NA, NA, 48604, NA, 36948, 52266,
50393, 46403, 32617, 13078), Female = c(NA, NA, 55500, NA, 34798,
51115, 52386, 46742, 30123, 13718), City = c(NA, 5552, NA, NA,
1253, 4254, 5552, 6682, 9533, NA), Rural = c(NA, NA, NA, NA,
70493, 99127, 97228, 86483, 53207, NA)), row.names = c(NA, -10L
), class = c("tbl_df", "tbl", "data.frame"))
Above the UI:
library(tidyverse)
library(readr)
library(shiny)
library(stringr)
library(rebus)
pop <- read_csv("pop.csv")
pop$TotalPop <- str_replace_all(pop$TotalPop, pattern = fixed(","), replacement = "")
pop$Male <- str_replace_all(pop$Male, pattern = fixed(","), replacement = "")
pop$Female <- str_replace_all(pop$Female, pattern = fixed(","), replacement = "")
pop$City <- str_replace_all(pop$City, pattern = fixed(","), replacement = "")
pop$Rural <- str_replace_all(pop$Rural, pattern = fixed(","), replacement = "")
pop$District <- str_remove_all(pop$District, pattern = "[^[:alnum:]]")
pop$TotalPop <- as.numeric(pop$TotalPop)
pop$Male <- as.numeric(pop$Male)
pop$Female <- as.numeric(pop$Female)
pop$City <- as.numeric(pop$City)
pop$Rural <- as.numeric(pop$Rural)
pop$GazID <- as.character(pop$GazID)
pop$District <- str_trim(pop$District)
The UI:
ui <- fluidPage(
titlePanel("Population Data from VSO"),
sidebarLayout(
sidebarPanel(
selectInput(inputId = "y", #internal label
label = "Population to map", #label that user sees
choices = c("Total population" = "TotalPop",
"Male population" = "Male",
"Female population" = "Female",
"Urban population" = "City",
"Rural population" = "Rural"),
selected = "TotalPop"),
selectizeInput(inputId = "d",
label = "Select district",
choices = c(pop$District),
multiple = TRUE, # can choose multiple
options = list(maxItems = 5))),
mainPanel(
plotOutput("plot")
)
)
)
The server:
server <- function(input, output) {
pop_subset <- reactive({
req(input$d)
filter(pop, District %in% c(input$d)
)})
output$plot <- renderPlot({
ggplot(data = pop_subset(), aes_string(x = pop_subset()$District, y = input$y)) +
geom_col(aes(fill = pop_subset()$District)) +
labs(x = "District", y = "Population") +
scale_fill_discrete(name = "Districts")
})}
shinyApp(ui = ui, server = server)

Answer 1

The problem is that you are using aes_string in your ggplot, but trying to pass District without quotes. I realize you need aes_string because you are using input$y, so just change your plot call to
output$plot <- renderPlot({
req(pop_subset())
ggplot(data = pop_subset(), aes_string(x = "District", y = input$y)) +
geom_col(aes(fill = District)) +
labs(x = "District", y = "Population") +
scale_fill_discrete(name = "Districts")
})
For reproducibility, packages and some sample data (no idea of its true representative nature, doesn't really matter I think).
library(dplyr)
library(shiny)
library(ggplot2)
set.seed(42)
n <- 50
pop <- data_frame(
TotalPop = sample(1e4, size=n, replace=TRUE)
) %>%
mutate(
Male = pmax(0, TotalPop - sample(1e4, size=n, replace=TRUE)),
Female = TotalPop - Male,
City = sample(LETTERS, size=n, replace=TRUE),
District = sample(letters, size=n, replace=TRUE)
)