带有主题标签的jQuery远程自动完成

Question

我在Stackoverflow找到了完美的解决方案。此代码检测@标签，而不是自定义单词的自动完成程序。

jQuery(function(){
        function getCaretPosition(e) {    
            if (typeof e.selectionStart == 'number') {
                return e.selectionStart;
            } else if (document.selection) {
                var range = document.selection.createRange();
                var rangeLength = range.text.length;
                range.moveStart('character', -e.value.length);
                return range.text.length - rangeLength;
            }
        }

        function setCaretPosition(e, start, end) {
            if (e.createTextRange) {
                var r = e.createTextRange();
                r.moveStart('character', start);
                r.moveEnd('character', (end || start));
                r.select();
            } else if (e.selectionStart) {
                e.focus();
                e.setSelectionRange(start, (end || start));
            }
        }

        function getWordBeforeCaretPosition(e) {    
            var s = e.value;
            var i = getCaretPosition(e) - 1;
            while (i >= 0 && s[i] != ' ') {
                i = i - 1;
            }             
            return i + 1;    
        }

        function getWordBeforeCaret(e) {  
            var p = getWordBeforeCaretPosition(e);
            var c = getCaretPosition(e);  
            return e.value.substring(p, c);    
        }

        function replaceWordBeforeCaret(e, word) {
            var p = getWordBeforeCaretPosition(e);
            var c = getCaretPosition(e);        
            e.value = e.value.substring(0, p) + word + e.value.substring(c);
            setCaretPosition(e, p + word.length);                     
        }

        jQuery("#"+commentAreaId).bind("keydown", function(event){
            if (event.keyCode === jQuery.ui.keyCode.TAB && jQuery(this).data("autocomplete").menu.active ) {
                event.preventDefault();
            }
        })
        .autocomplete({
            minLength: 2,
            source: function(request, response) {                 
                var w = getWordBeforeCaret(this.element[0]);  
                if (w[0] != '@') {
                    this.close();
                    return false;
                }             
                response(jQuery.ui.autocomplete.filter(completerData, w.substring(1, w.length)));                
                return true;             
            },
            focus: function() {
                return false;
            },           
            search: function(event, ui) {
                return true;
            },
            select: function(event, ui) {             
                replaceWordBeforeCaret(this, ui.item.label + '|' + ui.item.value );              
                return false;                   
            }
        }); 
    });

但我不明白，如何通过JSON使其与远程数据源一起工作。 还有更清洁和完美的实现吗？ 感谢