How to change border color of Bootstrap-select

Question

For a custom framework like Bootstrap select https://silviomoreto.github.io/bootstrap-select/ how do I change the border color of a select box in Javascript?

I tried th

Answer 1

If you see the DOM element generated by bootstrap-select, it actually hides the original select element and creates its own structure with div,span and buttons. There isn't any official documentation provided to change its border, but as a workaround you could do it as below:

You need to change border of the button whose class is btn dropdown-toggle btn-default, which is generated by bootstrap-select. Since the element created will not be given any id we will make use of its class with document.getElementsByClassName("classnames")[0]

document.getElementsByClassName("btn dropdown-toggle btn-default")[0].style.borderColor = "red";

---

Update

Explanation in comments.

$(document).ready(function() {
  //add a change event to each selectpicker
  $('.selectpicker').selectpicker().on('change', function() {
    var id = $(this).attr('id'); //get current element's id
    var selected = $(this).find("option:selected").val(); //get current element's selected value
    var condition = false; //default false to form valid
    $(this).selectpicker('setStyle', 'btn-danger', selected == "" ? "add" : "remove");
    if (id == "box") {//if its first select box
      condition = !(selected == 2 || selected == ""); //check if its value==2 or value=="" so that form validation depends of respective selects
      $("#box2").selectpicker(selected == 2 ? "show" : "hide").val("");
      //show or hide box2 based on selected val
      $("#box2").selectpicker('setStyle', 'btn-danger',"remove");
      //remove danger from 2nd selectpicker when its hidden or shown
    } else {
      condition = !(selected == "");
      //if its box 2 check if any value is selected
    }
    $(this).closest('form').data('valid', condition);
    //set it to form's data-valid attribute
  });
  $("#box2").selectpicker('hide');//default hide on page load
  
  //form submit event instead of validate() inline function
  $("form").on("submit", function(e) {
    e.preventDefault();//prevent default action of submit
    var isValid = $(this).data('valid');//check if its valid
    if (!isValid) {
      //if not valid loop through each selectpicker
      $.each($('.selectpicker'),function(){
        var selected=$(this).val();
        //check appropriate values for each select and set/remove the btn-danger class for respective selectpickers
        $(this).selectpicker('setStyle', 'btn-danger', selected == "" ? "add" : "remove"); 
      })
    }
    else{
      alert(isValid);
      //Submit your form
    }
  })
});

  
    select number
    1
    2
  
  
    select number
    1
    2
  
  

    submit