Selector是利用css selector来匹配选择页面元素的,所以要理解Selector首先应该对css selector有所理解,下面是css2 selector的语法,当然很多浏览器只是支持其中的一部分,Prototype 中的Selector主要支持tag选择器、class选择器和id选择器,还有属性(attribute)选择器,基本上包含我们平时所用的所有类型
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]"
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