Tree does not render when modal is re-opened

[m-merchant]

The following app has a button, Show, that opens a modal dialog when clicked. The modal contains a shinyTree with the search feature enabled and a datatable. When the modal is opened for the first time, both the tree and the datatable are rendered:

However, when the modal is dismissed and re-opened, the DT is rendered but the tree is not:

The screenshot above shows that the searchbox of the tree is rendered but its nodes are missing.

I can get around this by putting input$show inside renderTree but was wondering why it doesn't re-render without it like the DT.

Here is the code to reproduce the above:

library(shiny)
library(shinyTree)
library(DT)

tree = list(a=list(a1=1,a2=2) , b="b")
  
tree = lapply(tree, function(x) structure(x, stopened = T))

# UI

ui <- fluidPage(
  actionButton('show', 'Show modal')
)

# server

server <- function(input, output, session) {
  
  
  output$tree = renderTree({
    # input$show
    
    tree
    
  })
  
  output$data = renderDT({
    
    iris 
    
  })
  
  observeEvent(input$show, {
    
    showModal(modalDialog(
      shinyTree("tree", search = T), 
      DTOutput('data')
    ))
    
  })
}

shinyApp(ui, server)

[m-merchant]

In addition to re-rendering the tree when the modal is reopened, is there a way to also preserve the selected nodes when the modal is reopened? I am currently using a workaround that makes use of delay() and addClass from shinyjs. Here is my updated code:

library(shiny)
library(shinyTree)
library(shinyjs)
library(DT)

tree = list(a=list(a1=1,a2=2) , b="b")

tree = lapply(tree, function(x) structure(x, stopened = T))

# UI

ui <- fluidPage(
  useShinyjs(),
  actionButton('show', 'Show modal')
)

# server

server <- function(input, output, session) {
  
  
  output$tree = renderTree({
    
    input$show
    
    tree
    
  })
  
  output$data = renderDT({
    
    iris 
    
  })
  
  observeEvent(input$show, {
    
    showModal(modalDialog(
      shinyTree("tree", checkbox = T, search = T, themeIcons = F, theme = 'proton'), 
      DTOutput('data')
    ))
    
    # Add 'jstree-clicked' class to selected nodes
    delay(1000, {
      ids = lapply(get_selected(input$tree, 'classid'), function(x) attr(x, 'id'))
      
      lapply(ids, function(x) addClass(id = paste0(x, '_anchor'), class = 'jstree-clicked'))
    })
    
  })
}

shinyApp(ui, server)

So if you select node a2 and dismiss the modal, then when you subsequently reopen it, the tree is re-rendered with node a2 selected.

[bellma-lilly]

When input$tree changes, save the contents in "tree". The state is preserved in the structure. (The only thing that isn't saved is the types. I have code to fix that which I have not submitted yet)

[MayaGans]

@bellma-lilly would you mind adding that logic to my reprex below? I've encountered the same error:

library(shiny)
library(shinyTree)

ui = basicPage(
    actionButton("show", "Show modal dialog")
)

server = function(input, output) {
    
    output$tree <- renderTree({
        list(
            root1 = "",
            root2 = list(
                SubListA = list(leaf1 = "", leaf2 = "", leaf3=""),
                SubListB = list(leafA = "", leafB = "")
            ),
            root3 = list(
                SubListA = list(leaf1 = "", leaf2 = "", leaf3=""),
                SubListB = list(leafA = "", leafB = "")
            )
        )
    })
    
    observeEvent(input$show, {
        showModal(modalDialog(
                    shinyTree("tree", stripes = TRUE, multiple = FALSE, animation = FALSE)
        ))
    })
}


# Run the application 
shinyApp(ui = ui, server = server)

Thank you!

[trafficonese]

As @m-merchant noted, you can get around this error, if you add input$show in the renderTree section. But anyway, I hope @bellma-lilly can soon find some time to include the fix.

[MayaGans]

Ah I see that now, thanks!!!