R/mod_varselect.R

In MayaGans/golem_demo: Golem Demo Using Ames Housing Data App

#' Variable selection for plot user interface
#'
#' @param id, character used to specify namespace, see \code{shiny::\link[shiny]{NS}}
#'
#' @return a \code{shiny::\link[shiny]{tagList}} containing UI elements
mod_varselect_ui <- function(id){
  
  ns <- NS(id)
  
  # define choices for X and Y variable selection
  var_choices <- list(
    `Sale price` = "Sale_Price",
    `Total basement square feet` = "Total_Bsmt_SF",
    `First floor square feet` = "First_Flr_SF",
    `Lot Frontage` = "Lot_Frontage",
    `Lot Area` = "Lot_Area",
    `Masonry vaneer area` = "Mas_Vnr_Area",
    `1st floor square feet` = "First_Flr_SF",
    `2nd floor square feet` = "Second_Flr_SF",
    `Low quality finished square feet` = "Low_Qual_Fin_SF",
    `Above grade living area square feet` = "Gr_Liv_Area",
    `Garage area square feet` = "Garage_Area"
  )
  
  # assemble UI elements
  tagList(
    selectInput(
      ns("xvar"),
      "Select X variable",
      choices = var_choices,
      selected = var_choices[[4]]
    ),
    selectInput(
      ns("yvar"),
      "Select Y variable",
      choices = var_choices,
      selected = var_choices[[1]]
    ),
    selectInput(
      ns("groupvar"),
      "Select facet variable",
      choices = list(
        `None` = "",
        `House Style` = "House_Style",
        `Roof Style` = "Roof_Style",
        `Land Contour` = "Land_Contour",
        `Lot Shape` = "Lot_Shape",
        `Basement Exposure` = "Bsmt_Exposure",
        `Central Air` = "Central_Air",
        `Overall Condition` = "Overall_Cond"
      )
    )
  )
}
    
#' Variable selection module server-side processing
#'
#' @param input,output,session standard \code{shiny} boilerplate
#'
#' @return list with following components
#' \describe{
#'   \item{xvar}{reactive character indicating x variable selection}
#'   \item{yvar}{reactive character indicating y variable selection}
#'   \item{facetvar}{reactive character indicating variable used for defining plot facets}
#' }
mod_varselect_server <- function(input, output, session){
  
  ns <- session$ns
  
  return(
    list(
      xvar = reactive({ input$xvar }),
      yvar = reactive({ input$yvar }),
      facetvar = reactive({
        if (input$groupvar == "") {
          return(NULL)
        } else {
          return(input$groupvar)
        }
      })
    )
  )
 
}
    
## To be copied in the UI
# mod_varselect_ui("varselect_ui_1")
    
## To be copied in the server
# callModule(mod_varselect_server, "varselect_ui_1")