jQuery扩展事件变量

Question

该插件具有此变量

this.onValid = options.onValid || function(){ this.insertMessage(this.createMessageSpan()); this.addFieldClass(); };

问题是，当我定义一个新实例时，我想要向this.onValid添加一个新函数，我不想覆盖默认事件？

如何扩展变量this.onValid？

Answer 1

this.onValid = options.onValid || function(){ this.insertMessage(this.createMessageSpan()); this.addFieldClass(); };
//That above is already defined;
this._onValid = this.onValid; //Make a backup function
this.onValid = function (){
    this._onValid(); //Call the actual function
    //Your extended code here //Call your code
}

这是特定于您的代码的。为了更好地理解它，这个例子可能会有所帮助：

writeA = function (){
    document.write('a');
};
//Now I want to extend the writeA function to write 'b' as well
_writeA = writeA;
writeA = function (){
    _writeA(); //So now I call whatever the function originally did
    document.write('b'); //And now I execute what I want to add to the function
};

Example's demo

我只是试着修复你在评论中提供的代码。试试这个：

var obj1 = {
    this._onValid = this.onValid; //Do this assuming this.onValid is already defined
    onValid: function(){ //Redefine it
        this._onValid();
        newFunction();
    }

};

编辑

来自插件的。只需将其编辑为如下所示：

  this.onValid = options.onValid || function(){ this.insertMessage(this.createMessageSpan()); this.addFieldClass(); };
  this._onValid = this.onValid;
  this.onValid = function (){
        this._onValid();
        //YOUR CODE HERE
  };

我已经编辑了原始文件，使其看起来像那个here.

哈，我刚刚意识到我在这里放了和开始时一样的代码。好吧，那是因为这就是它应该看起来的样子。查看我编辑过的文件，搜索//YOUR CODE HERE并在其中添加代码。