I have this piece of code:
我有这段代码:
var myObj = function () {
this.complex = function (text) { /* long piece of code */ }
this.parse(text) {
return text.replace(/valid_pattern/gi, function (
I have this piece of code:
我有这段代码:
var myObj = function () {
this.complex = function (text) { /* long piece of code */ }
this.parse(text) {
return text.replace(/valid_pattern/gi, function ($1) { return this.complex($1); } );
}
}
Of course calling this.complex($1) won't do the trick, because I'm in the scope of the anonymous function. I can't re-scope the anonymous function using .call(this) statement either, because in th ta case I would lose the parameters passed to the function by String.replace.
当然调用this.complex($ 1)将无法解决问题,因为我处于匿名函数的范围内。我也不能使用.call(this)语句重新定义匿名函数的范围,因为在这种情况下,我将失去String.replace传递给函数的参数。
So far I'm using the concrete instance of the object. This is my solution:
到目前为止,我正在使用该对象的具体实例。这是我的解决方案:
var instance = new myObj;
var myObj = function () {
this.complex = function (text) { /* long piece of code */ }
this.parse(text) {
return text.replace(/valid_pattern/gi, function ($1) { return instance.complex($1); } );
}
}
So far it's sufficient to my needs, but I'm wondering if there is any universal solution to this problem. The only idea that has worked for me so far is this:
到目前为止,它足以满足我的需求,但我想知道是否有任何通用的解决方案来解决这个问题。到目前为止,唯一对我有用的想法是:
function ($1) { return (new myObj).complex($1); }
... which suffers from serious performance issues. Any ideas would be greatly appreciated.
......遭遇严重的性能问题。任何想法将不胜感激。
-- D.
P. S. Sorry about my English, it's not my first language.
P. S.对我的英语很抱歉,这不是我的第一语言。
3 个解决方案
#1
Maybe try:
var myObj = function () {
this.complex = function (text) { /* long piece of code */ }
this.parse(text) {
var that = this;
return text.replace(/valid_pattern/gi, function ($1) { return that.complex($1); } );
}
}
It is one of the most useful tricks :-)
这是最有用的技巧之一:-)
UPDATE: The trick is not mine, I learned it (as most of things I know about Javascript) from: Douglas Crockford
更新:诀窍不是我的,我从以下方面学到了它(我所知道的关于Javascript的大部分内容):Douglas Crockford
#2
This is what prototype and others do
这是原型和其他人所做的
// Monkey Patching, not everyone likes it
Function.prototype.bind = function( obj ) {
var _this = this;
return function() {
return _this.apply( obj, arguments )
}
}
Now you can do this
现在你可以做到这一点
var myObj = function () {
this.complex = function (text) { /* long piece of code */ }
this.parse = function(text) {
return text.replace(/valid_pattern/gi, function ($1) { return this.complex($1); }.bind( this ) );
}
}
O = new myObj();
alert( O.parse( 'some text' );
#3
declare a variable for that.
为此声明一个变量。
var myObj = function () {
var foo = this.complex = function (text) { /* long piece of code */ }
this.parse(text) {
return text.replace(/valid_pattern/gi, foo );
}
}
) { return this.complex(
I have this piece of code:
我有这段代码:
var myObj = function () {
this.complex = function (text) { /* long piece of code */ }
this.parse(text) {
return text.replace(/valid_pattern/gi, function ($1) { return this.complex($1); } );
}
}
Of course calling this.complex($1) won't do the trick, because I'm in the scope of the anonymous function. I can't re-scope the anonymous function using .call(this) statement either, because in th ta case I would lose the parameters passed to the function by String.replace.
当然调用this.complex($ 1)将无法解决问题,因为我处于匿名函数的范围内。我也不能使用.call(this)语句重新定义匿名函数的范围,因为在这种情况下,我将失去String.replace传递给函数的参数。
So far I'm using the concrete instance of the object. This is my solution:
到目前为止,我正在使用该对象的具体实例。这是我的解决方案:
var instance = new myObj;
var myObj = function () {
this.complex = function (text) { /* long piece of code */ }
this.parse(text) {
return text.replace(/valid_pattern/gi, function ($1) { return instance.complex($1); } );
}
}
So far it's sufficient to my needs, but I'm wondering if there is any universal solution to this problem. The only idea that has worked for me so far is this:
到目前为止,它足以满足我的需求,但我想知道是否有任何通用的解决方案来解决这个问题。到目前为止,唯一对我有用的想法是:
function ($1) { return (new myObj).complex($1); }
... which suffers from serious performance issues. Any ideas would be greatly appreciated.
......遭遇严重的性能问题。任何想法将不胜感激。
-- D.
P. S. Sorry about my English, it's not my first language.
P. S.对我的英语很抱歉,这不是我的第一语言。
3 个解决方案
#1
Maybe try:
var myObj = function () {
this.complex = function (text) { /* long piece of code */ }
this.parse(text) {
var that = this;
return text.replace(/valid_pattern/gi, function ($1) { return that.complex($1); } );
}
}
It is one of the most useful tricks :-)
这是最有用的技巧之一:-)
UPDATE: The trick is not mine, I learned it (as most of things I know about Javascript) from: Douglas Crockford
更新:诀窍不是我的,我从以下方面学到了它(我所知道的关于Javascript的大部分内容):Douglas Crockford
#2
This is what prototype and others do
这是原型和其他人所做的
// Monkey Patching, not everyone likes it
Function.prototype.bind = function( obj ) {
var _this = this;
return function() {
return _this.apply( obj, arguments )
}
}
Now you can do this
现在你可以做到这一点
var myObj = function () {
this.complex = function (text) { /* long piece of code */ }
this.parse = function(text) {
return text.replace(/valid_pattern/gi, function ($1) { return this.complex($1); }.bind( this ) );
}
}
O = new myObj();
alert( O.parse( 'some text' );
#3
declare a variable for that.
为此声明一个变量。
var myObj = function () {
var foo = this.complex = function (text) { /* long piece of code */ }
this.parse(text) {
return text.replace(/valid_pattern/gi, foo );
}
}
); } );
}
}
var myOb
