I am creating a Shiny App and have ran into an issue where I get an "Argument is of Length Zero" error when attempting to filter data based on my complex UI filtering system.
The UI filtering system works as follows:
The client selects date ranges for the data The client selects the team(s) to analyze from a CheckboxInput (choices = Team 1, Team 2) The client selects a category of analysis from a SelectInput (Choices = Overview, Age, Position, Players) a) If the client selects "Overview" nothing should happen (this will show an overview of the data means) b) if the client selects "Age" a new SelectInput appears below which allows the client to select an age range for analysis (choices = "less than 20", "20-23", "23-25", "25-30", "more than 30") c) if the client selects "Position" a new SelectInput appears below which allows the client to select the position for analysis (choices = Forwards, Defensemen, Goalies) d) Lastly, if the client selects "Player" a new SelectInput appears below which allows the client to select a player to analyze their individual data (choices = There are many individual players who could be selected) In the server, I would like to then create plots based on the filtering system. As you can see in the below code, filtering based on Date and Team is easy. However, when I include some IF statements (note I do not have all the required IF statements just yet) to filter the dynamic filters that change based on the input of the category filter, I receive an "Argument is of Length Zero" error.
My hypothesis is that when the app opens, the category filter is set to "Overview" as a default. Therefore, the Age, Position and Player filters do not yet exist so the server can not find these filters, and displays a "Argument is of Length Zero" error. Note: if I delete the IF statements, the error is removed (of course the app doesn't do what I want it to but this may provide some insight into the fact that the error is specifically within the IF statements).
Here is the relevant code:
'''
ui <- dashboardPage(
fluidRow(
box(title = "Athlete Body Composition",
plotOutput("plot1")),
box(collapsible =TRUE,
title = "Filters",
dateRangeInput("daterange", "Select Date Range",
start = "2019-01-01",
end = Sys.Date(),
min = "2019-01-01",
max = Sys.Date(),
format = "yyyy/mm/dd",
separator = "-"),
checkboxGroupInput("Teaminput", "Select Team", c("Team 1", "Team 2")),
selectInput( "Category", "Select Category", c("Overview", "Position", "Age", "Player")),
uiOutput('outputfilter'))
),
)
server <- function(session, input, output) {
observeEvent(input$Category,{
categoryfilterinput<- paste(input$Category)
output$outputfilter <- renderUI({
switch(categoryfilterinput,
"Position" = selectInput("positioninput", "Select Position", choices = c("Forwards","Defencemen", "Goalies")),
"Age" = selectInput("ageinput", "Select Age Range", choices = c("less than 20","20-23", "23-25", "25-30", "more than 30")),
"Player" = selectInput("Playernameinput", "Select Player", choices = Roster$Playername))
})
})
output$plot1 <- renderPlot({
filtered_data1 <- filter(DataFrame, Date >= format(input$daterange[1]) & Date <= format(input$daterange[2])) %>%
filter(Team %in% input$Teaminput)
if (input$category == "Player") {
filtered_data1 <- filtered_data1 %>% filter(Playername %in% input$Playernameinput)
}
if (input$category == "Overview") {
filtered_data1 <- filtered_data1
}
ggplot(filtered_data1, aes(x= Date, y = Weight)) +
geom_point(size=2)
})
}
'''
Any Help would be great!!
Here is the head of DataFrame
Playername Date Team Weight
chr date fct dbl
1 Player 1 2019-11-09 Team 1 94
2 Player 1 2019-11-16 Team 1 96
3 Player 2 2019-11-23 Team 2 95
4 Player 2 2019-11-30 Team 2 95.2
5 Player 1 2019-11-03 Team 1 NA
6 Player 1 2019-12-27 Team 1 NA
