我正在尝试向对象中的每个函数添加一个钩子(Hook),以下是我的代码,并且运行良好。
function foo(){}
foo.beforeMethodHook = function(){console.log('Hook was called.');}
foo.getInstance = function(){
var newInstance = new foo;
var funcNames = Object.getOwnPropertyNames(foo);
for(i in funcNames){
var funcName = funcNames[i];
if(funcName == 'getInstance' || funcName == 'beforeMethodHook' || Object.hasOwnProperty(funcName)) continue;
newInstance[funcName] = function (){
foo.beforeMethodHook();
return foo[this].apply(foo,arguments);
}.bind(funcName);
}
return newInstance;
}
foo.test1 = function(arg1){console.log('test1 was called. arg1 = ' + arg1);return true;}
foo.test2 = function(arg1,arg2){console.log('test2 was called. arg1 = ' + arg1 + ' , arg2 = ' + arg2);return true;}
//Test
var f = foo.getInstance();
f.test1('ahaha');
f.test2('heihei','houhou');
由于IE10-不支持function(){}.bind(),我尝试将.bind()更改为(function(){})(),如下
newInstance[funcName] = (function (){
foo.beforeMethodHook();console.log(arguments);
return foo[funcName].apply(foo,arguments);
})(funcName);
但问题来了,我失去了f.test1('ahaha')已经通过的论点。参数数组仅给出 ["test1"],即函数名称。
我该如何解决这个问题?提前致谢。
最佳答案
您可以实现自己的绑定(bind)
。简易版:
if (!Function.prototype.bind) {
Function.prototype.bind = function(that) {
var fn = this;
return function() {
fn.apply(that, arguments);
}
};
}
或正确的版本:
if (!Function.prototype.bind) {
Function.prototype.bind = function (oThis) {
if (typeof this !== "function") {
// closest thing possible to the ECMAScript 5 internal IsCallable function
throw new TypeError("Function.prototype.bind - what is trying to be bound is not callable");
}
var aArgs = Array.prototype.slice.call(arguments, 1),
fToBind = this,
fNOP = function () {},
fBound = function () {
return fToBind.apply(this instanceof fNOP && oThis
? this
: oThis,
aArgs.concat(Array.prototype.slice.call(arguments)));
};
fNOP.prototype = this.prototype;
fBound.prototype = new fNOP();
return fBound;
};
}
代码取自:
https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Function/bind
关于javascript - 在 JavaScript 中使用 ()() 将参数传递给匿名函数,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/19679676/