CODEWITHSUNDEEP
rshiny
Kevin Tracey
Kevin Tracey

Reputation: 314

How to utilise the "splitColumn" button in R shiny with the source file "SplitColumn.R"

in R Shiny, The below code "app.R" takes a CSV file as an input file from the user and populates the data table in the main panel. sometimes the table has merged columns "Type" which I want to split using the function below. I would like to keep a button "SplitColumn" in R shiny that should do the same.

I'd want to utilize "splitColumn.R" as a source file in the R shiny app, so that when a user uploads a csv file, they can select the column name and push the "SplitColumn" button to get the results.

Because I'm new to Shiny, I'm having trouble connecting the action button (SplitColumn) with "splitColumn.R" at the server level.

I'm hoping for some assistance here.

CSV data contains:

before_merge<- data.frame(ID=21:23, Type=c('A1 B1', 'C1 D1', 'E1 F1'))

splitColumn.R

library(dplyr)
library(tidyr)
library(stringr)
library(tidyverse)
library(stringr)

library(svDialogs)
column_name <- dlg_input("Enter a number", Sys.info()["user"])$res

before_merge<- data.frame(ID=21:23, Type=c('A1 B1', 'C1 D1', 'E1 F1'))
before_merge

library(reshape2)

newColNames <- c("Unmerged_type1", "Unmerged_type2")
#column_name <- readline(prompt="Enter the desired column name: ")
newCols <- colsplit(before_merge[[column_name]], " ", newColNames)
after_merge <- cbind(before_merge, newCols)
after_merge[[column_name]] <- NULL

app.R

## Only run examples in interactive R sessions
if (interactive()) {
  
  ui <- fluidPage(
    sidebarLayout(
      sidebarPanel(
        fileInput("file1", "Choose CSV File", accept = ".csv"),
        checkboxInput("header", "Header", TRUE),
        actionButton("Splitcolumn", "SplitColumn"),
      ),
      mainPanel(
        tableOutput("contents")
      )
    )
  )
  
  server <- function(input, output) {
    output$contents <- renderTable({
      file <- input$file1
      ext <- tools::file_ext(file$datapath)
      
      req(file)
      validate(need(ext == "csv", "Please upload a csv file"))
      
      read.csv(file$datapath, header = input$header)
    })
  }
  
  shinyApp(ui, server)
}

Upvotes: 2

Views: 68

Answers (1)

Ronak Shah
Ronak Shah

Reputation: 389047

You can put your code of splitColumn.R in a function.

splitColumn <- function(data, column_name) {
  newColNames <- c("Unmerged_type1", "Unmerged_type2")
  newCols <- colsplit(data[[column_name]], " ", newColNames)
  after_merge <- cbind(data, newCols)
  after_merge[[column_name]] <- NULL
  after_merge
}

In app.R use observeEvent to call the function on click.

library(shiny)

source('SplitColumn.R')

ui <- fluidPage(
  sidebarLayout(
    sidebarPanel(
      fileInput("file1", "Choose CSV File", accept = ".csv"),
      checkboxInput("header", "Header", TRUE),
      actionButton("Splitcolumn", "SplitColumn"),
    ),
    mainPanel(
      tableOutput("contents")
    )
  )
)

server <- function(input, output) {
  rv <- reactiveValues(data = NULL)
  
  observe({
    file <- input$file1
    ext <- tools::file_ext(file$datapath)
    
    req(file)
    validate(need(ext == "csv", "Please upload a csv file"))
    
    rv$data <- read.csv(file$datapath, header = input$header)
    
  })
  
  output$contents <- renderTable({
    req(rv$data)
    rv$data
  })
  
  observeEvent(input$Splitcolumn, {
    rv$data <- splitColumn(rv$data, 'Type')
  })
}
shinyApp(ui, server)

Upvotes: 0

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