Add a select input

Adding an input to a shiny app is a two step process, where you first add an ___Input(“x”) function to the UI and then access its value in the server using input$x.

For example, if you want users to choose an animal from a list, you can use a selectInput, and refer to the chosen value as input$animal:

selectInput(
  'animal', 
  'Select Animal', 
  selected = 'Cat', 
  choices = c('Dog', 'Cat')
)

In this exercise, you will build a Shiny app that lets users visualize the top 10 most popular names by sex by adding an input to let them choose the sex.

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Building Web Applications with Shiny in R

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Add a select input named "sex" to let users choose between "M" and "F", with a default of "F".
Update server code to get the top 10 names for the chosen sex instead of "F" only.

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ui <- fluidPage(
  titlePanel("What's in a Name?"),
  # CODE BELOW: Add select input named "sex" to choose between "M" and "F"

  # Add plot output to display top 10 most popular names
  plotOutput('plot_top_10_names')
)

server <- function(input, output, session){
  # Render plot of top 10 most popular names
  output$plot_top_10_names <- renderPlot({
    # Get top 10 names by sex and year
    top_10_names <- babynames %>% 
      # MODIFY CODE BELOW: Filter for the selected sex
      filter(sex == "F") %>% 
      filter(year == 1900) %>% 
      slice_max(prop, n = 10)
    # Plot top 10 names by sex and year
    ggplot(top_10_names, aes(x = name, y = prop)) +
      geom_col(fill = "#263e63")
  })
}

shinyApp(ui = ui, server = server)

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