CODEWITHSUNDEEP
rshinyreactive-programming
S.Kang
S.Kang

Reputation: 611

R shiny, How to use selectInput function well?

I have folders(A,B,C) and files(a,b,c). The folders are all in the same directory.

Each folder has all the files.

Example: FolderA has files(A-a,A-b,A-c), FolderB has files(B-a,B-b,B-c) and FolderC has files(C-a,C-b,C-c).

So, I want to show a list of these.

This is the output what I want:

enter image description here

When I select Folder B, I want to show the file list for Folder B on (Smaller Category)-selectInput. And if I press the action button, I want to use the reactive function to process the data for that path(Folder B/CsvFile B-c).

global.R

getFromGlobalR <- memoise(function(path){
       execution code...
}

ui.R

fluidPage(
  titlePanel("selectInput"),
  fluidRow(
    uiOutput("larger_category"),
    uiOutput("smaller_category"),
    uiOutput("action_btn")
  )
)

server.R

executed_statement <- reactive({
    input$action_btn

    isolate({
        if(input$smaller=="") return()
        getFromGlobalR(input$smaller)
    })
})

output$larger_category <- renderUI({
    selectInput("larger", "select folder", choices =list.dirs(path = "./FolderDir", full.names = FALSE, recursive = FALSE))  
})

output$smaller_category <- renderUI({
    selectInput("smaller", "select files", choices = ?)   
})

output$action_btn <- renderUI({
  actionButton("actionBtn", class="btn-primary", "search")
})

I don't know what to put in the choices parameter for output$smaller_category.

I tried to use choices=list.files(paste("./",input$larger,sep=""), ".csv"). But It's not worked.

Also, I don't know if it works fine even if I put the choices parameter in output$smaller_category.

Any ideas?

Upvotes: 0

Views: 406

Answers (1)

OmaymaS
OmaymaS

Reputation: 1731

Debugging

First of all you need to debug and see your values by using browser() or printing the values, for example:

  • In the server output$d <- renderPrint(input$larger)

  • In the ui verbatimTextOutput("d")

Possible Issues

  • selectInput defaults to the first value for single-select lists if selected is not set.

  • If FolderDir is reactive, it will have an effect.

Upvotes: 1

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