jquery tagit

(function($){
    $.widget("ui.tagit",{
        options:{
            placeholder:"placeholder",
            maxlength:40,
            tagSource:[],
            triggerKeys:["enter","space","comma","tab"],
            initialTags:[],
            minLength:1,
            select:true,
            allowNewTags:true,
            emptySearch:false
        },
        _keys:{
            backspace:[8],
            enter:[13],
            space:[32],
            comma:[191],
            tab:[9]
            },
        _create:function(){
            $.ui.autocomplete.prototype._renderItem=function(ul,item){
                var re=new RegExp("^"+this.term);
                var t=item.label.replace(re,'<span class="autocompleteBold">'+this.term+"</span>");
                if(item.extra){
                    t='<span class="autocompleteExtra">'+item.extra+":</span> "+t
                    }
                    return $("<li></li>").data("item.autocomplete",item).append("<a>"+t+"</a>").appendTo(ul)
                };

            var self=this;
            this.tagsArray=[];
            this.timer=null;
            this.element.addClass("tagit");
            this.element.children("li").each(function(){
                self.options.initialTags.push($(this).text())
                });
            this.element.html('<li class="tagit-new"><input placeholder="'+this.options.placeholder+'" class="tagit-input" type="text" maxlength="'+this.options.maxlength+'" /></li>');
            this.input=this.element.find(".tagit-input");
            $(this.element).click(function(e){
                if($(e.target).hasClass("tagit-close")){
                    $(e.target).parent().remove();
                    var text=$(e.target).parent().text();
                    self._popTag(text.substr(0,text.length-1))
                    }else{
                    self.input.focus();
                    if(self.options.emptySearch&&$(e.target).hasClass("tagit-input")&&self.input.val()==""&&self.input.autocomplete!=undefined){
                        self.input.autocomplete("search")
                        }
                    }
            });
    var os=this.options.select;
    this.options.appendTo=this.element;
    this.options.source=this.options.tagSource;
    this.options.highlight=true;
    this.options.select=function(event,ui){
        clearTimeout(self.timer);
        if(ui.item.extraeng){
            self._addTag(ui.item.value, ui.item.extraeng)
        } else {
            self._addTag(ui.item.value);
        }
        return false
        };

    this.input.autocomplete(this.options);
        this.options.select=os;
        this.input.keydown(function(e){
        var lastLi=self.element.children(".tagit-choice:last");
        if(e.which==self._keys.backspace){
            return self._backspace(lastLi)
            }
            if(self._isInitKey(e.which)){
            e.preventDefault();
            if(self.options.allowNewTags&&$(this).val().length>=self.options.minLength){
                self._addTag($(this).val())
                }else{
                if(!self.options.allowNewTags){
                    self.input.val("")
                    }
                }
        }
    if(lastLi.hasClass("selected")){
        lastLi.removeClass("selected")
        }
        self.lastKey=e.which
    });
this.input.blur(function(e){
    var v=$(this).val();
    if(self.options.allowNewTags){
        self.timer=setTimeout(function(){
            self._addTag(v)
            },200)
        }
        $(this).val("");
    return false
    });
String.prototype.trim=function(){
    return this.replace(/^\s+|\s+$/g,"")
    };

if(this.options.select){
    this.element.after('<select class="tagit-hiddenSelect" name="'+$(this.element).parent().children(".tagitid").attr("id")+'" multiple="multiple"></select>');
    this.select=this.element.siblings(".tagit-hiddenSelect")
    }
    this._initialTags()
    },
_popSelect:function(text){
    this.select.children('option[value="'+text+'"]').remove();
    this.select.change()
    },
_addSelect:function(value,extraeng){
        this.select.append('<option selected="selected" value="'+value+'">'+value+"</option>");
    this.select.change()
    },
_popTag:function(text){
    $.inArray(text,this.tagsArray);
    if(text==undefined){
        text=this.tagsArray.pop()
        }else{
        var index=($.inArray(text,this.tagsArray)==-1?this.tagsArray.length-1:$.inArray(text,this.tagsArray));
        this.tagsArray.splice(index,1)
        }
        if(this.options.select){
        this._popSelect(text)
        }
    },
_addTag:function(value, extraeng){
    this.input.val("");
    value=value.replace(/,+$/,"");
    value=value.trim();
    if(value==""||this._exists(value)){
        return false
        }
        var tag="";
    tag='<li class="tagit-choice">'+value+'<a class="tagit-close">x</a></li>';
    $(tag).insertBefore(this.input.parent());
    this.input.val("");
    this.tagsArray.push(value);
    if(this.options.select){
        this._addSelect(value,extraeng)
        }
        return true
    },
_exists:function(value){
    if(this.tagsArray.length==0||$.inArray(value,this.tagsArray)==-1){
        return false
        }
        return true
    },
_isInitKey:function(keyCode){
    var keyName="";
    for(var key in this._keys){
        if($.inArray(keyCode,this._keys[key])!=-1){
            keyName=key
            }
        }
    if($.inArray(keyName,this.options.triggerKeys)!=-1){
    return true
    }
    return false
},
_removeTag:function(){
    this._popTag();
    this.element.children(".tagit-choice:last").remove()
    },
_backspace:function(li){
    if(this.input.val()==""){
        if(this.lastKey==this._keys.backspace){
            this._popTag(li.html().replace('<a class="tagit-close">x</a>',""));
            li.remove();
            this.lastKey=null
            }else{
            li.addClass("selected");
            this.lastKey=this._keys.backspace
            }
        }
    return true
},
_initialTags:function(){
    var input=this;
    if(this.options.initialTags.length!=0){
        this.options.initialTags.each(function(i){
            input._addTag(i)
            })
        }
    },
tags:function(){
    return this.tagsArray
    },
destroy:function(){
    $.Widget.prototype.destroy.apply(this,arguments);
    this.tagsArray=[]
    }
})
})(jQuery);