Set opacity 0 to modal-backdrop when another background already shown

Question

I use BlockUI plugin in my app to block user screen when some action are executed. Some times when blockUI is in use bootstrap modal opens with it's modal-backdrop which made background much darker.

$.fn.myBlockUI = function () {
    var loader = $('#img-loader');

    .blockUI({
        message: loader,
        css: {
            border: 'none',
            padding: '5px',
            'background-color': 'transparent',
            '-webkit-border-radius': '10px',
            '-moz-border-radius': '10px',
            opacity: .6,
            color: '#fff',
            cursor: 'wait'
        }
    });
}

This is my function which i add to ajax call on beforeSend.

$.fn.myBlockUI = function () {
    var loader = $('#img-loader');

    $('.modal').on('shown.bs.modal', function(e) {
        $(".modal-backdrop").addClass('modal-backdrop-no-background');
    });
    $('.modal').on('hidden.bs.modal', function(e) {
        $(".modal-backdrop").removeClass('modal-backdrop-no-background');
    });

    $.blockUI({
        message: loader,
        css: {
            border: 'none',
            padding: '5px',
            'background-color': 'transparent',
            '-webkit-border-radius': '10px',
            '-moz-border-radius': '10px',
            opacity: .6,
            color: '#fff',
            cursor: 'wait'
        }
    });
}

this is my "solution" which doesn't work now. I thought when i call this function add class with opacity : 0 to remove one background, but this doesn't work.

Answer 1

General Sibling Selector selects all elements that are siblings of a specified element.

element ~ element {...}

Example:

.modal-backdrop {
  position: fixed;
  top: 0;
  right: 0;
  bottom: 0;
  left: 0;
  z-index: 1040;
  background-color: #000;
  opacity: 0.5;
}


.modal-backdrop ~ .modal-backdrop {
  display: none;
}

<div class="modal-backdrop"></div>
<div class="modal-backdrop"></div>
<div class="modal-backdrop"></div>