Backbone model triggering dropdown change event twice

nspace("siriusd.views");

(function ($, _, window, document) {

siriusd.views.DropdownFilterView = siriusd.views.FilterView.extend({

events: {

"change": "changeFilter"

},

initialize: function (options) {

siriusd.views.DropdownFilterView.__super__.initialize.apply(this, arguments);

this.el = options.el;

this.filterKeys = options.filterKeys;

this.setValue();

this.collection.setFilter(this.filter);

},

setValue: function () {

var value = this.getSelectedValue();

// don't filter on options with value set to zero

if (parseInt(value, 10) === 0) {

this.removeFilter(this.filterKeys.selected);

} else {

this.addFilter(this.filterKeys.selected, value);

}

},

resetValue: function () {

if (this.$el.attr('id') != 'domain' && this.$el.attr('id') != 'subject' && this.$el.attr('id') != 'focusarea' && this.$el.attr('id') != 'topic') {

this.$el.find("option:first").attr('selected', 'selected');

this.$el.trigger('change');

this.$el.heapbox('update');

}

// avoid to getitems call for subject , focusarea, topic new ...

else if (this.$el.attr('id') == 'domain') {

$("#domain").val($("#domain option:first").val());

$("#domain").trigger('change');

}

},

changeFilter: function () {

this.setValue();

this.collection.setFilter(this.filter);

this.filtrate();

},

getSelectedValue: function () {

if (this.$el.attr('id') == 'subject') {

if (this.$el.find(":selected").val() != '') {

return ($("#domain").find(":selected").val() + '::' + this.$el.find(":selected").val());

}

else {

return ($("#domain").find(":selected").val());

}

}

else if (this.$el.attr('id') == 'focusarea') {

if (this.$el.find(":selected").val() != '') {

return ($("#domain").find(":selected").val() + '::' + $("#subject").find(":selected").val() + '::' + this.$el.find(":selected").val());

}

else {

return ($("#domain").find(":selected").val() + '::' + $("#subject").find(":selected").val());

}

}

else if (this.$el.attr('id') == 'topic') {

if (this.$el.find(":selected").val() != '') {

return ($("#domain").find(":selected").val() + '::' + $("#subject").find(":selected").val() + '::' + $("#focusarea").find(":selected").val() + '::' + this.$el.find(":selected").val());

}

else {

return ($("#domain").find(":selected").val() + '::' + $("#subject").find(":selected").val() + '::' + $("#focusarea").find(":selected").val());

}

}

else {

return (this.$el.find(":selected").val());

}

}

});

})(jQuery, _, window, document);