Add user input column to Shiny - r

Question

I am trying to gather user input given a data set. I want to insert a column where the user can determine whether they would want to own one of the cars in the mtdata set. This is completely subjective as opinions differ from person to person so I am not able to program this in. Is there a way to append an extra column that can be a checkbox or dropdown menu to identify cars that a user would "Want to own?
library(shiny)
shinyApp(ui = shinyUI(fluidPage(
titlePanel("Interesting Cars"),
sidebarLayout(
sidebarPanel(
helpText("This is a side bar")),
mainPanel(
tableOutput("view")
)
)
)),
server = function(input, output) {
output$view <- renderTable({
head(mtcars[, 1:4], n = 6)
})
})

Answer 1

How about this, you can use the DT library. By adding the filter option the user can define the different components one wants and see what cars come up.
library(shiny)
library(DT)
shinyApp(ui = shinyUI(fluidPage(
titlePanel("Interesting Cars"),
sidebarLayout(
sidebarPanel(
helpText("This is a side bar")),
mainPanel(
DT::dataTableOutput("view")
)
)
)),
server = function(input, output) {
output$view <- DT::renderDataTable({
datatable(mtcars,
filter = "top"
)
})
})
Edit
If it truly is so important to add another column indicating if it is 'interesting' there will be significantly more code to written if you intend to have users assign it on different conditions. Here is an example with just the mpg. The fundamental idea here is that you assign your data to the reactiveValues function. It can then be modified as you like. This can obviously be improved upon more (as it will continue to add columns) but it demonstrates the concept.
shinyApp(ui = shinyUI(fluidPage(
titlePanel("Interesting Cars"),
sidebarLayout(
sidebarPanel(
helpText("This is a side bar"),
uiOutput("mpg"),
actionButton("add_label", "Mark Interesting")
),
mainPanel(
DT::dataTableOutput("view")
)
)
)),
server = function(input, output) {
values <- reactiveValues(
mydata = mtcars
)
output$mpg <- renderUI({
numericInput("mpg_input", "MPG Cutoff?",
value = 15
)
})
output$view <- DT::renderDataTable({
datatable(values$mydata
)
})
observeEvent(input$add_label, {
validate(
need(!is.null(input$mpg_input), "need mpg value")
)
values$mydata <- data.frame(values$mydata,
Interesting_Flag =
ifelse(values$mydata$mpg > input$mpg_input,
"Interesting",
"Not Interesting"))
})
})