Append data to existing dataframe in R

[vinayprakash808]

Hi Is there a way to append data to existing data in R. For example below application has dataframe populated based on user values , but right now, it is only creating new row and not appending.

Can we append this dataframe. I tried using reactive values as well. But did not work. Is there a way to achieve this?

library(shiny)

ui <- basicPage(
  
  fluidRow(
    column(
      width = 6,
      textInput('a', 'Text A',"a1"),
      textInput('b', 'Text B',"b1"),
      textInput('c', 'Text A',"c1"),
      textInput('d', 'Text B',"d1"),
      textInput('e', 'Text A',"e1"),
      textInput('f', 'Text B',"f1"),
      uiOutput('f1')
    ),
    column(
      width = 6,
      tags$p(tags$span(id = "valueA", "")),
      tags$script(
        "$(document).on('shiny:inputchanged', function(event) {
          if (event.name === 'a') {
            $('#valueA').text(event.value);
          }
        });
        "
      )
      ,tableOutput('show_inputs')
    )
  )
)

server <- shinyServer(function(input, output, session){
  
  output$f1 <- renderUI({
    if(input$a == "a2"){
      textInput('z', 'Text B',"z1")
    } else {
      NULL
    }
  })
  
  AllInputs <- reactive({
    x <- reactiveValuesToList(input)
    # print(x)
    # data.frame(
    #   names = names(x),
    #   values = paste0(unlist(x, use.names = FALSE), Sys.time())
    # )
    
    tibble(
      key = names(x),
      data = x
    ) %>% 
      mutate(data = map(data, as.character)) %>% 
      unnest(data)
  })
  
  # observe({
  #   if(file.exists("file.csv")){
  #     write.table(AllInputs(), "file.csv", sep = ",", col.names = F, append = T, row.names = F)
  #   } else {
  #     write.csv(AllInputs(), "file.csv", sep = ",", row.names = F)
  #   }
  #   
  # })
  
  output$show_inputs <- renderTable({
    
    AllInputs()
  })
})
shinyApp(ui = ui, server = server)

expected output (Provided if the user changes a, e and b values)

key	 data.x  data.y
a	 a1           fd
e	 e1           fg
b	 b1           gh
c	 c1           c1
d	 d1          d1
f	 f1           f1

[nirgrahamuk]

library(shiny)
library(tidyverse)

ui <- basicPage(
  
  fluidRow(
    column(
      width = 6,
      textInput('a', 'Text A',"a1"),
      textInput('b', 'Text B',"b1"),
      textInput('c', 'Text A',"c1"),
      textInput('d', 'Text B',"d1"),
      textInput('e', 'Text A',"e1"),
      textInput('f', 'Text B',"f1"),
      uiOutput('f1')
    ),
    column(
      width = 6,
      tableOutput('show_inputs')
    )
  )
)

server <- shinyServer(function(input, output, session){
  
  
  AllInputs <- reactiveVal(NULL)
  
  newest <- reactive({
    x <- reactiveValuesToList(input)

   tibble(
      key = names(x),
      data = x
    ) %>% 
      unnest(data)

  })
  
  observeEvent(newest(),{
    if(isTruthy(AllInputs())){
    AllInputs(merge(AllInputs(),newest(),
              by="key"))} else {
                AllInputs(newest())
              }
  })

  output$show_inputs <- renderTable({
    
    AllInputs()
  })
})
shinyApp(ui = ui, server = server)

[vinayprakash808]

Thanks. It is working.
But if you change Text A(input$a) to "a2", f1 gets generated and this is not printing

[nirgrahamuk]

I got rid of it. Its not relevant to whay you asked for help with.