JavaScript:如何将多个参数传递给对象成员内部的回调函数? [英] JavaScript: How to pass multiple arguments to a callback function inside an object's member?

问题描述

在使用插件时，有时会偶然发现一个类似这样的插件:

When working with plugins I sometimes stumble upon one that has something like this:

• 它将使用构造函数参数.
• 某些参数解析为函数.
• 其中一些会引起多种争论.

像这样:

{
    color: function (someData, moreData) {
        return someData + moreData;
    }
}

如何向该函数传递两个参数?

注意:我无法更改插件，因此不能将第二个参数移至另一个构造函数参数.

Note: I am unable to change the plugin, so moving the second argument to another constructor argument is not an option.

示例JavaScript:

Sample JavaScript:

(function ($) {
    $.fn.greenify = function (options) {
        var settings = $.extend({
            color: function (someData, moreData) { // <-- THIS TAKES 2 ARGUMENTS!
                return someData + moreData;
            },
        }, options);
        return this.css({
            color: settings.color,
        });
    };
}(jQuery));

$("#target1").greenify({
    color: "blue"
});

$("#target2").greenify({
    color: ["bl", "ue"]   // <-- In your answer only this should be changed
});

我的目标:

<div id="target1">My Thing</div>   // <-- will be blue
<div id="target2">My Thing2</div>  // <-- will be black but should be blue

游戏演示

更新: 我对这个代码

$("#target1").greenify({
    color: "blue"
});

会将值"blue"作为第一个参数someData传递给function (someData, moreData). 这是错误的！ 实际上发生的是默认回调(function (someData, moreData))被字符串"blue"完全替换了！

would hand the value "blue" over to function (someData, moreData) as first parameter someData. This is false! What actually happens is that the default callback (function (someData, moreData)) is completely replaced by the string "blue"!

推荐答案

如何将两个参数传递给该函数?

How do I pass two arguments to that function?

你不知道. jQuery确实如此.它是一个回调函数，可在.css()方法中动态确定color属性-请参见

You don't. jQuery does. It's a callback function to determine the color property dynamically in the .css() method - see the docs.

因此，实际上，该默认函数没有任何意义，因为它应该返回css颜色值，但返回以元素索引为前缀的旧值-绝对不是颜色.

So actually, that default function doesn't make any sense as it should return a css color value but returns the old value prefixed by the index of the element - which is definitely not a color.

所以只需使用$("#target2").greenify({color: "black"}).

如果您想传递一个函数，那也是可以的-但是它将覆盖，而不是调用该默认函数.一个例子:

If you want to pass a function, that is also possible - but it will overwrite, not call that default function. An example:

$("div").greenify({
    color: function(index, prevColor) {
        return ["blue", "black"][index % 2];
    }
});

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