jQuery" hasParent" [英] jQuery "hasParent"

问题描述

JQueryhas方法有效地选择了具有特定后代的所有元素。

The JQuery "has" method effectively selects all elements where they have particular descendants.

我想根据具有特定祖先的事实选择元素。我知道父母（[选择器]）和父母（[选择器]），但这些选择父母而不是父母的孩子。

I want to select elements based on the fact they have particular ancestors. I know about parent([selector]) and parents([selector]) but these select the parents and not the children with the parents.

那么是否有一个祖先等价物有？

So is there an ancestor equivalent of "has"?

注意：我已经在层次结构的下方有一个元素的上下文，我将基于此选择我无法进行自上而下查询。

Note: I already have the context of an element further down the hierarchy and I will be selecting based on this so I can't do a "top down" query.

更新

我显然在这里解释得非常糟糕，所以我会尝试澄清：

I've obviously explained myself really badly here, so I'll try and clarify:

<ul class="x">
  <li>1</li>
  <li>2</li>
  <li>3</li>
</ul>
<ul class="y">
  <li>4</li>
  <li>5</li>
  <li>6</li>
</ul>

我有一个jQuery对象，已经包含元素2,3,4和5.我想要选择那些拥有class = x父级的元素。

I have a jQuery object that already consists of elements 2,3,4 and 5. I want to select those elements who have a parent with the class = x.

希望更有意义。

推荐答案

对于干净的可重用解决方案，请考虑使用用于确定特定祖先存在的自定义方法扩展 jQuery.fn 对象对于任何给定元素：

For a clean re-usable solution, consider extending the jQuery.fn object with a custom method used for determining the presence of a particular ancestor for any given element:

// Extend jQuery.fn with our new method
jQuery.extend( jQuery.fn, {
    // Name of our method & one argument (the parent selector)
    within: function( pSelector ) {
        // Returns a subset of items using jQuery.filter
        return this.filter(function(){
            // Return truthy/falsey based on presence in parent
            return $(this).closest( pSelector ).length;
        });
    }
});

这会产生一种新方法， $。fn.within ，我们可以用来过滤我们的结果：

This results in a new method, $.fn.within, that we can use to filter our results:

$("li").within(".x").css("background", "red");

这将选择文档上的所有列表项，然后仅过滤到 .x 作为祖先。因为这在内部使用jQuery，你可以传入一个更复杂的选择器：

This selects all list items on the document, and then filters to only those that have .x as an ancestor. Because this uses jQuery internally, you could pass in a more complicated selector:

$("li").within(".x, .y").css("background", "red");

这会将集合过滤为从 .x下降的项目或 .y ，或两者兼而有之。

This will filter the collection to items that descend from either .x or .y, or both.

小提琴： http://jsfiddle.net/jonathansampson/6GMN5/

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