argument of length is zero. Program does not recognize option from SelectInput

Question

SelectInput function in ui is supposed to give me an option to choose "YES" or "NO". When "NO" is selected, it will choose the " if(("NO" %in% input$qualify_pit))" block in renderDataTable function in server and execute that perfectly. However, when I choose "YES" option, its block does not run, not displaying any table. I tried everything to get it to run its block (if(("YES" %in% input$qualify_pit))) but to no avail.

library(shiny)
library(shinythemes)
library(DT)

pit <- read.csv("PIT_STAT.csv")

pit_stat <- c("MLB_name","MLBId","LastName","FirstName","LW","W","L","Sv","BS","HLD","G","GS","CG","GF","QS","SHO","IP","BFP","H","X1B","X2B","X3B",
              "HR","R","ER","SH","SF","HBP","BB","IBB","BB_noIBB","K","WP","BLK","GB","FB","LD","POPU","SB",
              "CS","PKO","SVO","OUTS","K9","BB9","AVG","BABIP","HR9","GB_percent","HRperFB","ERA","KperBB",
              "K_percent","BB_percent","K_minus_BB","WHIP","LD_percent","FB_percent","GBperFB")

pit_def <- c("MLB_name","MLBId","LastName","FirstName","LW","W","L","ERA","IP","H","HR","R","ER","BB","K","K9","BB9","HR9","WHIP",
             "GB_percent","FB_percent","LD_percent","K_percent","BB_percent","KperBB","K_minus_BB")

ui <- shinyUI(fluidPage(

  shinythemes::themeSelector(),

  theme = shinytheme("paper"),

  titlePanel("WSFB Stats Lab"),

  fluidRow(
    uiOutput("uis")
  ),

  fluidRow(

    tabsetPanel(id = "tabs",
                tabPanel("Pitch Table",dataTableOutput("pitch_table"))
    )
  )


)
)


server <- shinyServer(function(input, output, session){


    output$uis <- renderUI({

      if(input$tabs == "Pitch Table")
      {
        pit <- read.csv("PIT_STAT.csv")

        pit_stat <- c("MLB_name","MLBId","LastName","FirstName","LW","W","L","Sv","BS","HLD","G","GS","CG","GF","QS","SHO","IP","BFP","H","X1B","X2B","X3B",
                      "HR","R","ER","SH","SF","HBP","BB","IBB","BB_noIBB","K","WP","BLK","GB","FB","LD","POPU","SB",
                      "CS","PKO","SVO","OUTS","K9","BB9","AVG","BABIP","HR9","GB_percent","HRperFB","ERA","KperBB",
                      "K_percent","BB_percent","K_minus_BB","WHIP","LD_percent","FB_percent","GBperFB")

        pit_def <- c("MLB_name","MLBId","LastName","FirstName","LW","W","L","ERA","IP","H","HR","R","ER","BB","K","K9","BB9","HR9","WHIP",
                     "GB_percent","FB_percent","LD_percent","K_percent","BB_percent","KperBB","K_minus_BB")

        wellPanel(
          checkboxGroupInput('show_vars', 'Variables to display', pit_stat, inline = TRUE, selected = pit_def),
          selectInput("qualify_pit","MIN IP:",choices = c("YES","NO"))
        )

      }
    })


  output$pitch_table <- renderDataTable({

    if(("YES" %in% input$qualify_pit))
    {
      pit <- read.csv("PIT_STAT.csv")
      pit2 <- pit[pit$IP >= 162,]
      DT::datatable(pit2[,input$show_vars, drop = FALSE])

    }

    if(("NO" %in% input$qualify_pit))
    {
      pit <- read.csv("PIT_STAT.csv")
      DT::datatable(pit[,input$show_vars, drop = FALSE])

    }

  })


})

shinyApp(ui = ui, server = server)

score 0 · Answer 1 · edited May 23 '17 at 12:01

It works with NO because the DT:datatable is the last expression of the function, therefore it is the implicit return value.

But for the YES, which is not the last evaluation (the if("NO" %in%... is), you have to explicitly use return:

return(DT::datatable(pit2[,input$show_vars, drop = FALSE]))

Otherwise you can simply use else

  output$pitch_table <- renderDataTable({
    if(("YES" %in% input$qualify_pit))
    {
      DT::datatable(pit[pit$IP >= 162,input$show_vars, drop = FALSE])
    }
    else 
    {
      DT::datatable(pit[,input$show_vars, drop = FALSE])
    }
  })

For more details about using return you can read this thread

argument of length is zero. Program does not recognize option from SelectInput

1 Answers1