Element.prototype in IE7?

懵懂的女人 提交于 2019-12-28 15:56:09

问题


I'm trying to extend all dom elements so i can get and remove their children. The function is below (works in FF and Chrome). Is there an equivalent in IE7 to extend the base dom object?

if (!Element.get) {
Element.prototype.get = function(id) {
    for (var i = 0; i < this.childNodes.length; i++) {
        if (this.childNodes[i].id == id) {
            return this.childNodes[i];
        }
        if (this.childNodes[i].childNodes.length) {
            var ret = this.childNodes[i].get(id);
            if (ret != null) {
                return ret;
            }
        }
    }
    return null;
}
}

Element.prototype.removeChildren = function() {
    removeChildren(this);
}

Thanks!


回答1:


No. There will be some limited support in IE8, but 'till then you're better off finding another place to hang your functions.




回答2:


Here is a simple workaround that will be sufficient in 99% of cases. It may as well be completed as required by your script :

if ( !window.Element ) 
{
    Element = function(){};

    var __createElement = document.createElement;
    document.createElement = function(tagName)
    {
        var element = __createElement(tagName);
        if (element == null) {return null;}
        for(var key in Element.prototype)
                element[key] = Element.prototype[key];
        return element;
    }

    var __getElementById = document.getElementById;
    document.getElementById = function(id)
    {
        var element = __getElementById(id);
        if (element == null) {return null;}
        for(var key in Element.prototype)
                element[key] = Element.prototype[key];
        return element;
    }
}



回答3:


IE do not have "Element" set, so you can't access the prototype of Element to directly add your function. The workaround is to overload "createElement" and "getElementById" to have them return an element with a modified prototype with your function.

Thanks to Simon Uyttendaele for the solution!

if ( !window.Element )
{
        Element = function(){}

        Element.prototype.yourFunction = function() {
                alert("yourFunction");
        }


        var __createElement = document.createElement;
        document.createElement = function(tagName)
        {
                var element = __createElement(tagName);
                for(var key in Element.prototype)
                        element[key] = Element.prototype[key];
                return element;
        }

        var __getElementById = document.getElementById
        document.getElementById = function(id)
        {
                var element = __getElementById(id);
                for(var key in Element.prototype)
                        element[key] = Element.prototype[key];
                return element;
        }
}


来源:https://stackoverflow.com/questions/597268/element-prototype-in-ie7

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