A select helper for handlebars

handlebars-select-helper.js

Handlebars.registerHelper("select", function(value, options) {
  return options.fn(this)
    .split('\n')
    .map(function(v) {
      var t = 'value="' + value + '"'
      return ! RegExp(t).test(v) ? v : v.replace(t, t + ' selected="selected"')
    })
    .join('\n')
})

How to create it for multiple selection.

multiselect: function (selected, option) {
        if(selected == undefined) {
            return '';
        }
        return selected.indexOf(option) !== -1 ? 'selected' : '';
    }

<div class="form-group col-6">
            <label for="booking_type">Booking Type</label>
            <select name="booking_type" id="booking_type" class="form-control" multiple>
                <option value="one_way_transfer" {{{multiselect ptb.booking_type "one_way_transfer"}}}>One Way Transfer</option>
                <option value="two_way_transfer" {{{multiselect ptb.booking_type "two_way_transfer"}}}>Two Way Transfer</option>
                <option value="nightclub_tour" {{{multiselect ptb.booking_type "nightclub_tour"}}}>Nightclub Tour</option>
                <option value="kids_bus_party" {{{multiselect ptb.booking_type "kids_bus_party"}}}>Kids Bus Party</option>
            </select>
        </div>

Worked like a charm! Thanks.