R: get sum from selected Input - r

Question

I am relative new to R and trying to learn on my own.
I want to create in a shiny dashboard a select-field where i can choose products of my Data (.xls) and get a sum returned.
The Input is via selectInput and selectize. This is the part, which works :)
If I choose 1 product i'll get the calories of this product back...so far.
My Problem is that wanna choose more products then 1 and get the sum of the calories. How do i have to identify/search the products of the input field in my table and how do i get the sum of it?
Thanks a lot for your help!
PS: Do you need further info about file? only two columns are important for this: product and calories.
library(dplyr)
library(plotly)
library(readxl)
library(shiny)
library(shinydashboard)
# Daten einlesen
McDaten <- read_excel("~/Desktop/McDaten.xlsx")
McDaten$kcal <- McDaten$`kcal (100g)`
ui <- dashboardPage(
skin="red",
dashboardHeader(title = "Analytics Dashboard", titleWidth = 290),
dashboardSidebar(
width = 290,
sidebarMenu(
menuItem("Virtuelles Menü", tabName = "charts", icon = icon("cutlery"))
)
),
dashboardBody(
tabItems(
tabItem(tabName = "charts",
fluidPage(
br(),
fluidRow(
column(4,
selectInput('in6', 'Menü', McDaten$Produkt, multiple=TRUE, selectize=TRUE)),
column(4,infoBoxOutput("progressBox"))
)
)
))))
server <- function(input, output) {
output$progressBox <- renderInfoBox({
b <- McDaten %>%
select(`kcal (Portion)`, Produkt) %>%
filter(McDaten$Produkt %in% input$in6) %>%
summarise(`kcal (Portion)`)
infoBox(
"Progress", paste0(b, " kcal"), icon = icon("list"),
color = "purple", fill = TRUE
)
})
}
shinyApp(ui, server)

Answer 1

We need the choices = unique(McDaten$Produkt) in the 'ui' and in summarise the sum needs to be specified for the column of interest
-ui
ui <- dashboardPage(
skin="red",
dashboardHeader(title = "Analytics Dashboard", titleWidth = 290),
dashboardSidebar(
width = 290,
sidebarMenu(
menuItem("Virtuelles Menü", tabName = "charts", icon = icon("cutlery"))
)
),
dashboardBody(
tabItems(
tabItem(tabName = "charts",
fluidPage(
br(),
fluidRow(
column(4,
selectInput('in6', 'Menü',
choices = unique(McDaten$Produkt), multiple=TRUE, selectize=TRUE )),
column(4,infoBoxOutput("progressBox"))
)
)
))))
-server
server <- function(input, output) {
output$progressBox <- renderInfoBox({
b <- McDaten %>%
select(`kcal (Portion)`, Produkt) %>%
filter(Produkt %in% input$in6) %>%
summarise(`kcal (Portion)` = sum(`kcal (Portion)`)) %>%
pull(`kcal (Portion)`)
infoBox(
"Progress", paste0(b, " kcal"), icon = icon("list"),
color = "purple", fill = TRUE
)
})
}
-run the app
shinyApp(ui, server)
-data
set.seed(24)
McDaten <- data.frame(Produkt = sample(LETTERS[1:5], 30, replace = TRUE),
`kcal (Portion)` = sample(1400:2000, 30, replace = TRUE),
stringsAsFactors= FALSE, check.names = FALSE)
McDaten$kcal <- McDaten$`kcal (Portion)`
-output