AngularJS Example:

HTML

<link rel="stylesheet" href="http://twitter.github.com/bootstrap/assets/css/bootstrap.css">
<div ng-app>
    <div ng-controller="ctrl">
        <select ng-model="type">
            <option val="short">short</option>
            <option val="long">long</option>
        </select>
        <select>
            <option ng-repeat="item in items" ng-if="doTest(item)">{{item.name}}</option>
        </select>
        </div< </div>

CSS

.short {
    background-color:red
}
.long {
    background-color:blue
}

JavaScript

function ctrl($scope) {

    $scope.items = [{
        name: 'Foo',
        short: true,
        long: false
    }, {
        name: 'Bar',
        short: true,
        long: true
    }, {
        name: 'Foobar',
        short: false,
        long: true
    }]

    $scope.doTest = function (item) {

        if ($scope.type) {
            return item[$scope.type];
        }
        return false;

    }

}