R shiny dashboard is not recognizing newly variables I have created in code

[zmcclean]

Hello Everyone,
As the Title of my post states, I am currently creating a R shiny dashboard and when I create a new variable (i.e. renaming a previous df that I now have filtered), R shiny is not finding the new variable and then reporting a "argument is of length zero" error.

I know that the code itself is correct because if I take that new variable separately and run it in a different R sheet, it works well and the variable is correctly added to the global environment.

However, like I said, in the R shiny dashboard code these new variables are not being added to the global environment.

Any help on this topic would be awesome! I really appreciate the help!

[nirgrahamuk]

you are probably not making a reactive dataframe which would be the way to go for a shiny app.

Chapter 4 Basic reactivity | Mastering Shiny

[zmcclean]

Thank you so much for the help! Can you clarify the issue for me using the example I provide? This is part of my server function. The "filtereddata1" variable is not being recognized.

  server <- function(session, input, output) { output$plot1 <- renderPlot({

      filtereddata1 <-  filter(mergedTrainingdf, Date >= input$daterange[1] & Date <= input$daterange[2]) %>% 
                        filter(Team == input$Teaminput)
      
      if (input$category == "Player") {filterdata1 <- filtereddata1 %>% 
                                       filter(Playername %in% input$Playernameinput)
      }
      if (input$category == "Overview") {filtereddata1 <- filtereddata1
      }
      
      ggplot(filtereddata1, aes(x= Date, y = Weight)) +
                            geom_point(size=2)
      
})
}

[nirgrahamuk]

you seem to have inconsistent spellings filtereddata1 filterdata1
In principle your code is fine and works

library(shiny)
library(tidyverse)

(mergedTrainingdf <- tibble(
  Date = seq.Date(
    from = Sys.Date() - 10,
    by = "day",
    length.out = 10
  ),
  Team = c(rep("A", 6), rep("B", 4)),
  Playername = letters[1:10],
  Weight = 1:10
))

ui <- fluidPage(
  shiny::dateRangeInput("daterange",
    label = "dates",
    start = Sys.Date() - 10,
    end = Sys.Date()
  ),
  selectInput("Teaminput",
    label = "Teaminput",
    choices = unique(mergedTrainingdf$Team)
  ),
  radioButtons("category",
    label = "category",
    choices = c("Player", "Overview"), selected = "Player"
  ),
  selectInput("Playernameinput",
    label = "Playernameinput",
    choices = mergedTrainingdf$Playername,
    multiple = TRUE,
    selected = mergedTrainingdf$Playername
  ),
  plotOutput("plot1")
)



server <- function(session, input, output) {
  output$plot1 <- renderPlot({
    f1 <- filter(mergedTrainingdf, Date >= input$daterange[1] & 
                   Date <= input$daterange[2]) %>%
      filter(Team == input$Teaminput)

    if (input$category == "Player") {
      f2 <- f1 %>%
        filter(Playername %in% input$Playernameinput)
    }
    if (input$category == "Overview") {
      f2 <- f1
    }

    ggplot(f2, aes(x = Date, y = Weight)) +
      geom_point(size = 2)
  })
}
shinyApp(ui, server)

[zmcclean]

Thanks a lot for the help. Spelling mistakes are not ideal...
However, even when fixing that, it still doesn't work.

I have had this problem a couple of times with my project. This project has two csv files that are inputted at the beginning of the code. csv file1 loaded correctly, however, I had the same issue where csv file 2 was not put into the global environment until I ran it in a different R file tab.

This issue has happened a few times.

[nirgrahamuk]

i dont know what to change in my example of your code, to break it...

[zmcclean]

Thanks for looking into it for me. I must have an error somewhere in my code but it is obviously difficult to find.
I appreciate the help nonetheless

[nirgrahamuk]

Here is a link with some resources regarding shiny debugging
Shiny debugging and reprex guide