inst/shiny/examples/4_communication/module/DatasetSelector.R

In xni7/tidymodules: A robust framework for developing shiny modules

DatasetSelector <- R6::R6Class(
  classname = "DatasetSelector",
  inherit = Panel,
  public = list(
    initialize = function(...){
      # Mandatory
      super$initialize(...)
      
      # Ports definition starts here
      self$definePort({
        # Add an output port (optional)
        self$addOutputPort(
          name = "dataset",
          description = "the selected dataset from environment by data()",
          sample = head(mtcars))
      })
    },
    ui = function() {
      super$ui(
        status = "primary",
        fluidRow(
          column(12,uiOutput(outputId = self$ns("selectDatasetUI"))),
          column(12,style = "overflow:auto",
                 tableOutput(
                   outputId = self$ns("selectedDataset"))
          )
        )
      )
    },
    server = function(input, output, session){
      # Mandatory
      super$server(input,output,session)
      
      output$selectDatasetUI <- renderUI({
        allDatasets <- as.data.frame(data()$results)
        allDatasets <- as.character(allDatasets$Item)
        selectInput(inputId = self$ns("selectData"), 
                    label = "Select dataset", 
                    choices = allDatasets, 
                    selected = allDatasets[1],
                    selectize = TRUE)
      })
      output$selectedDataset <- renderTable({
        allDatasets <- as.data.frame(data()$results)
        dataset <- getData()
        if(is(dataset,"data.frame"))
          allDatasets[which(allDatasets$Item == input$selectData),]
        else
          "Not a table!"
      })
      
      getData <- reactive({
        tryCatch({
          dataName <- input$selectData
          req(!is.null(dataName))
          print(dataName)
          dataset <- get(dataName)
        }, error = function(e){
          NULL
        })
      })
      
      # Server logic
      modOut <- reactive({
        dataset <- getData()
        req(is(dataset,"data.frame"))
        print(dim(dataset))
        return(dataset)
      })
      
      # Ports assignment starts here
      self$assignPort({
        
        self$updateOutputPort(
          id = "dataset",
          output = modOut)
        
      })
      
      return(modOut)
      
    }
  ),
  private = list(
    # any private functions?
  )
)