Javascript jquery oop重写方法函数
您好,我想知道如果我的方法声明如下,如何重写方法函数:Javascript jquery oop重写方法函数,javascript,jquery,oop,overriding,Javascript,Jquery,Oop,Overriding,您好,我想知道如果我的方法声明如下,如何重写方法函数: (function ($) { $.extend({ tablesorter: new function () { function buildHeaders(table) { console.log('ORIGINAL HEADERS'); } this.construct = function
(function ($) {
$.extend({
tablesorter: new
function () {
function buildHeaders(table) {
console.log('ORIGINAL HEADERS');
}
this.construct = function (settings) {
return this.each(function () {
$headers = buildHeaders(this);
});
}
}
});
$.fn.extend({
tablesorter: $.tablesorter.construct
});
})(jQuery);
我的目标是完全重写tableSorterbuildHeaders函数
(function ($) {
var originalMethod = $.fn.tablesorter;
$.fn.tablesorter = function() {
console.log('overiding');
function buildHeaders(table) {
console.log('OVERRIDE HEADERS');
}
originalMethod.apply(this, arguments);
}
})(jQuery);
(function ($) {
$.extend({
tablesorter: new
function () {
var self = this; //preserve the context
this.buildHeaders = function (table) {
//you can customize the template method anyway you want
this.buildHeadersCore(table);
}
this.buildHeadersCore = function (table){
console.log('ORIGINAL HEADERS');
}
this.construct = function (settings) {
return this.each(function () {
$headers = self.buildHeaders(this);//call via "self" instead of "this" because "this" now refers to jquery object, not the tablesorter anymore
});
}
}
});
$.fn.extend({
tablesorter: $.tablesorter.construct
});
})(jQuery);
function inherit(proto) {
var F = function() { };
F.prototype = proto;
return new F();
}
(function ($) {
var tablesorterExtended = inherit($.tablesorter);
tablesorterExtended.buildHeadersCore = function (table){
console.log('OVERRIDE HEADERS');
}
$.fn.tablesorterExtended = tablesorterExtended.construct;
//or you can even use your old name. The point is the original buildHeaders function is not lost when you replace.
//$.fn.tablesorter = tablesorterExtended.construct;
})(jQuery);
这不管用。。。任何帮助都会很好。谢谢
$.extend
不是扩展jQuery的正确方法,而是一种jQuery实用程序方法。您应该使用$.fn.extend
。那么它应该会起作用。如果没有,也尝试使用
(function ($) {
var originalMethod = $.fn.tablesorter;
$.fn.extend({
tablesorter: function() {
console.log('overiding');
function buildHeaders(table) {
console.log('OVERRIDE HEADERS');
}
originalMethod.apply(this, arguments);
}
})
})(jQuery);
您可以在此处阅读更多内容:
希望这能有所帮助。简短回答:不行。
函数中的函数(即,buildHeaders
是另一个函数中的函数)是私有的,不能重写。以这个简单的示例为例,猜测输出:
// A very simple function inside a function
test = function() {
function buildHeaders() {
alert("original buildHeaders called");
}
buildHeaders();
}
// Now lets take a backup of the "test" function
oldTest = test;
// And try to override a private function
test = function() {
function buildHeaders() {
alert("duplicate buildHeaders called");
}
oldTest.apply(this, arguments);
}
// Call
test();
为什么?
我认为您是在Java(或类似的)背景下尝试这一点的,在这里您覆盖了实际的方法。在Javascript中,您不重写函数,而是替换它们。i、 e
function x() { } // Original function
oldX = x // Original function is now oldX
x = function() { } // x is now a **NEW** function
// we did not override, we replaced
// At this point, oldX and x are two different functions
// You just swapped their names, but x is no longer the original x
这一部分很清楚。现在进入第二部分,私有/局部变量:
function x() {
var y = 0;
}
x();
alert(y); // No, you cannot access "y" from outside
但让我们来看看:
function x() {
y = 0; // Without "var"
}
x();
alert(y); // Alerts "0"!!
如果您给出var y=0
,则它在该函数中变为私有。如果不这样做,它将变为全局范围(从技术上讲是更高范围的,但我们暂时不考虑)
第三部分,函数中的函数默认为私有函数。以同样的例子来说
function x() {
function y() { }
// this is the same as saying:
var y = function() { }
// note "var y", so you can't override this from outside
}
因此,如果通常在函数中定义函数,如function x(){function y(){}}
,那么y
是x
的私有函数。再加上这一点,您永远无法覆盖javascript中的函数,只能替换。因此,您将永远无法访问或修改该y
,除非从原始x
功能中进行访问或修改
(function ($) {
var originalMethod = $.fn.tablesorter;
$.fn.tablesorter = function() {
console.log('overiding');
function buildHeaders(table) {
console.log('OVERRIDE HEADERS');
}
originalMethod.apply(this, arguments);
}
})(jQuery);
(function ($) {
$.extend({
tablesorter: new
function () {
var self = this; //preserve the context
this.buildHeaders = function (table) {
//you can customize the template method anyway you want
this.buildHeadersCore(table);
}
this.buildHeadersCore = function (table){
console.log('ORIGINAL HEADERS');
}
this.construct = function (settings) {
return this.each(function () {
$headers = self.buildHeaders(this);//call via "self" instead of "this" because "this" now refers to jquery object, not the tablesorter anymore
});
}
}
});
$.fn.extend({
tablesorter: $.tablesorter.construct
});
})(jQuery);
function inherit(proto) {
var F = function() { };
F.prototype = proto;
return new F();
}
(function ($) {
var tablesorterExtended = inherit($.tablesorter);
tablesorterExtended.buildHeadersCore = function (table){
console.log('OVERRIDE HEADERS');
}
$.fn.tablesorterExtended = tablesorterExtended.construct;
//or you can even use your old name. The point is the original buildHeaders function is not lost when you replace.
//$.fn.tablesorter = tablesorterExtended.construct;
})(jQuery);
唯一的选择
只有在您有权访问某个函数时,才能使用自定义实现替换该函数。因此,您必须编辑原始函数,或者以某种方式必须在函数外部保存对buildHeaders
的引用。i、 e.您必须执行以下操作之一:
// ...
tablesorter: new function() {
this.buildHeaders = function() { }
// ...
}
// and later, you can replace this:
tablesorter.buildHeaders = function() { // alternative code }
您将能够重写该函数,因为它不是私有的,并且您有一个句柄来访问它
编辑:次要语法有以下几种方法:
- 按照RDX的答案来做:存储对
的引用并完全替换它(记住将上下文存储为buildHeaders
,在this
构造中
函数引用jquery对象,而不是
)表排序器
- 为什么不采取更简单的方法:只需在第一块代码中修改原始函数。我想你不这样做的原因是因为你不想失去原来的函数,否则你可以用这个简单的方法代替第一种方法
(function ($) {
var originalMethod = $.fn.tablesorter;
$.fn.tablesorter = function() {
console.log('overiding');
function buildHeaders(table) {
console.log('OVERRIDE HEADERS');
}
originalMethod.apply(this, arguments);
}
})(jQuery);
(function ($) {
$.extend({
tablesorter: new
function () {
var self = this; //preserve the context
this.buildHeaders = function (table) {
//you can customize the template method anyway you want
this.buildHeadersCore(table);
}
this.buildHeadersCore = function (table){
console.log('ORIGINAL HEADERS');
}
this.construct = function (settings) {
return this.each(function () {
$headers = self.buildHeaders(this);//call via "self" instead of "this" because "this" now refers to jquery object, not the tablesorter anymore
});
}
}
});
$.fn.extend({
tablesorter: $.tablesorter.construct
});
})(jQuery);
function inherit(proto) {
var F = function() { };
F.prototype = proto;
return new F();
}
(function ($) {
var tablesorterExtended = inherit($.tablesorter);
tablesorterExtended.buildHeadersCore = function (table){
console.log('OVERRIDE HEADERS');
}
$.fn.tablesorterExtended = tablesorterExtended.construct;
//or you can even use your old name. The point is the original buildHeaders function is not lost when you replace.
//$.fn.tablesorter = tablesorterExtended.construct;
})(jQuery);
这对他的代码不起作用,因为
$headers=buildHeaders(This)代码>再也找不到buildHeaders
函数。请记住,此
引用的是jquery对象,而不是表排序器
。如果OP将buildHeaders
更改为对象函数,而不是函数中的当前函数,则是-它们必须更新代码的其他部分。因此,总体答案是“不行”,当前代码不支持重写,任何更改都需要对现有代码进行轻微更改,这与OP在不修补现有代码的情况下重写内容的目标背道而驰。因此答案是不,你不能