ShinyDashboard 动态项目符号点

Question

I have hopefully a simple problem to pass a tags ordered list to in a Shiny Dashboard. What I'd like to do is have a function that makes an ordered list of bullet points based upon on a filtered category.

Here is a trivial example of what I'd like to be able to do with a data frame called nba_teams

teams    conference
Bulls    Eastern
Nuggets  Western
Celtics  Eastern
Lakers   Western

Now if I write this function it will break out the list for the respective conferences:

for (row in 1:nrow(nba_teams)){
  teams <- nba_teams[row, "teams"]
  conference <- nba_teams[row,"conference"]

  if(grepl("Western",conference)){
   print(tags$li(teams))
 }
}

Nuggets

Lakers

What I'd like to do is to have this in a tab box such that:

box(
 title = "Western Conference",
 tags$ol(
  for (row in 1:nrow(nba_teams)){
  teams <- nba_teams[row, "teams"]
  conference <- nba_teams[row,"conference"]

  if(grepl("Western",conference)){
   print(tags$li(teams))
 }
})),

But this just leaves the box blank and won't populate the box with a bullet point for each observation.

Any suggestions? Thank you!

Answer 1

I would use lapply in this case:

library(shiny)  
library(shinydashboard)

nba_teams <- data.frame(team = c("Bulls", "Nuggest", "Celtics", "Lakers"),
                        conference = c("Eastern", "Western", "Eastern", "Western"))

ui <- dashboardPage(
  dashboardHeader(),
  dashboardSidebar(),
  dashboardBody(
    box(
      title = "Western Conference",
      tags$ol(
        lapply(1:nrow(nba_teams), function(x) {
          if (nba_teams$conference[x]=="Western") {
            return(tags$li(nba_teams$team[x]))
          }
        })
      )
    )
  )
)

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

shinyApp(ui, server)