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The following table summarizes CSS2 selector syntax, 详细的可以看http://www.w3.org/TR/REC-CSS2/selector.html:
Pattern | Meaning | Described in section |
---|---|---|
* | Matches any element. | Universal selector |
E | Matches any E element (i.e., an element of type E). | Type selectors |
E F | Matches any F element that is a descendant of an E element. | Descendant selectors |
E > F | Matches any F element that is a child of an element E. | Child selectors |
E:first-child | Matches element E when E is the first child of its parent. | The :first-child pseudo-class |
E:link E:visited | Matches element E if E is the source anchor of a hyperlink of which the target is not yet visited (:link) or already visited (:visited). | The link pseudo-classes |
E:active E:hover E:focus | Matches E during certain user actions. | The dynamic pseudo-classes |
E:lang(c) | Matches element of type E if it is in (human) language c (the document language specifies how language is determined). | The :lang() pseudo-class |
E + F | Matches any F element immediately preceded by an element E. | Adjacent selectors |
E[foo] | Matches any E element with the “foo” attribute set (whatever the value). | Attribute selectors |
E[foo=”warning”] | Matches any E element whose “foo” attribute value is exactly equal to “warning”. | Attribute selectors |
E[foo~=”warning”] | Matches any E element whose “foo” attribute value is a list of space-separated values, one of which is exactly equal to “warning”. | Attribute selectors |
E[lang|=”en”] | Matches any E element whose “lang” attribute has a hyphen-separated list of values beginning (from the left) with “en”. | Attribute selectors |
DIV.warning | HTML only. The same as DIV[class~=”warning”]. | Class selectors |
E#myid | Matches any E element ID equal to “myid”. | ID selectors |
Selector中包含Selector对象和类,
Selector对象具有下面两个方法:
match(element):元素是否与本selector匹配,在Element中已经介绍了
findElements(parentNode):parentNode中所有匹配本selector的子孙元素列表
使用方法也很简单 var s=new Selector(expression); s.match(element); s.findElements($(element)),其中expression可以是如下方式 "div"、"#id"、".class"、"div#id"、"div[attribute]"、"div[attribute=fff]"、"div[attribute!=sdf]"
其中Selector也有几个静态方法,它们分别是:
matchElements(elements, expression):返回elements中符合expression的元素列表
findElement(elements, expression, index):返回elements中符合expression的元素列表中索引为index的元素
findChildElements(element, expressions):找出element的子孙元素中符合expressions的元素列表,其中expressions是一个expression数组,其中的expression支持"div li.#id"形式
$$方法:只是简单的调用return Selector.findChildElements(document, $A(arguments))
虽然Selector有这么多方法,但是大部分都是内部调用的,我们一般都很少使用,因为我们有个一个方便的方法$$,对于绝大部分情况已经足够了JavaScript技术:Prototype使用指南之selector.js说明,转载需保留来源!
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