创建Javascript库不起作用

Question

This is my code:

(function(window, myObj) {
  window.onload = myObj.onload;
})(window, function() {
  this.onload = function() {
    console.log('Loading...');
  };
});

But it not working, when load page, nothing in web console. Somebody help me!!! Thank so much!

Answer 1

Let's separate out the functions.

var myFunc = function() {
  this.onload = function() {
    console.log('Loading...');
  };
};
(function(window, myObj) {
  window.onload = myObj.onload;
})(window, myFunc);

As we can see myFunc don't have method onload which we are trying to use on window.onload = myObj.onload

Either we can use

(function(window, myObj) {
     window.onload = myObj.onload;
   })(window, new myFunc()); // here myObj.onload will be availabel

Or we can have static method for onload defined in myFunc

var myFunc = function() {
};
myFunc.onload = function() {
    console.log('Loading...');
};
(function(window, myObj) {
  window.onload = myObj.onload;
})(window, myFunc);

Answer 2

The function what you pass into is not an object. So it won't have onload method.You can use the new operator to create a object.

 function Fun(){ this.onload = function() { console.log( 'Loading....' ); } } (function( window, myObj ){ window.onload = myObj.onload; })( window, new Fun() );