问引导TypeAhead.js防止无效条目

EN

    var sync = false;
    var current_results = [];
    var current_q = '';
    var selected_val = '';

    function search(q, sync) {
        current_q = q;
        window.sync = sync;
        engine.search(q, cust_sync);
    }

    function cust_sync(datums) {
      current_results = datums;
      sync(datums);
    }

    $('#typeahead').typeahead(
        {
          highlight: true,
          minLength: 0
        },
        {
            source: search // custom search engine
        }

    );

    $('#typeahead').bind('typeahead:change', function(ev) {
        var current_val = $('#typeahead').val();
        // user moved cursor out of input without selecting from the menu
        if(current_val != selected_val){
            // current query has search results
            if(current_results.length)
                // change input to the first valid search result
                $('#typeahead').typeahead('val', current_results[0].name); 
            // no results for this query - clear input
            else 
                $('#typeahead').typeahead('val', '');
            }
    });


    $('#typeahead').bind('typeahead:select', function(ev, suggestion) {
        selected_val = $('#typeahead').val(); // keep track of a selected value
    });