script to run selectize with grep functionality and clean up the created searches from the option list

selectizegrep

library(shiny)

shinyApp(
  ui = fluidPage(
    selectizeInput(inputId = "variable",
                   label = "Variable:",
                   choices = split(names(iris),gsub('[_.]',' ',names(iris))),
                   options=list(multiple=TRUE,create = TRUE)),
    checkboxGroupInput(inputId = 'grep',label = 'regex options',
                       choices = c('Enable'='enbl',
                                   'Retain Searches'='ret',
                                   'ignore.case'='ignore',
                                   'perl'='perl','fixed'='fixed','invert'='invert'),
                       selected = c('enbl','ignore'),
                       inline  = TRUE),
    tableOutput("data")
    ),
  server = function(input, output,session) {
    
    observe({
     if(!'ret'%in%input$grep){
          updateSelectizeInput(session=session,inputId = 'variable',choices = names(iris),selected = input$variable,options = list(multiple=TRUE,create=TRUE))
      }
    })
    
    observeEvent(input$variable,{
      
      if('enbl'%in%input$grep){
      curr_cols=switch((nchar(input$variable)==0)+1,
                       grep(input$variable,names(iris),
                            value=TRUE,
                            ignore.case = 'ignore'%in%input$grep,
                            perl = 'perl'%in%input$grep,
                            fixed='fixed'%in%input$grep,
                            invert='invert'%in%input$grep),
                       NULL)
      }else{
        curr_cols=switch((input$variable%in%names(iris))+1,names(iris),input$variable)
      }
      
        
      
      if(length(curr_cols)>0){
      if(all(curr_cols%in%names(iris))){
        output$data <- renderTable({
          iris[,curr_cols , drop = FALSE]
        }, rownames = TRUE)
      }}
      
    })
  })