我听说在内联元素中放入块元素是一种HTML错误:
<a href="http://example.com">
<div>
What we have here is a problem.
You see, an anchor element is an inline element,
and the div element is a block level element.
</div>
</a>
但是如果在样式表中将外部锚设置为display:block呢?还是错的吗?关于块级和内联元素的HTML 4.01规范似乎是这样认为的:
样式表提供了实现的方法
指定任意的呈现
元素,包括是否为元素
呈现为块或内联。在
有些情况,比如内联样式
对于列表元素,这可能是
恰当,但总的来说,
不鼓励作者
超越常规
HTML元素的解释
这种方式。
有没有人对这个问题有进一步的建议?
根据你要迎合的HTML版本:
HTML 5 states that the <a> element "may be wrapped around entire paragraphs, lists, tables, and so forth, even entire sections, so long as there is no interactive content within (e.g. buttons or other links)".
HTML 4.01 specifies that <a> elements may only contain inline elements. A <div> is a block element, so it may not appear inside an <a>.
Of course you are at liberty to style an inline element such that it appears to be a block, or indeed style a block so that it is rendered inline. The use of the terms inline and block in HTML refers to the relationship of the elements to the semantic structure of the document, whereas the same terms in CSS are related more to the visual styling of the elements. If you make inline elements display in a blocky manner, that's fine.
However you should ensure that the structure of the document still makes sense when CSS is not present, for example when accessed via an assistive technology such as a screen reader - or indeed when examined by the mighty Googlebot.
在http://www.w3.org/TR/REC-html40/sgml/dtd.html上有一个针对HTML 4的DTD。这个DTD是规范的机器可处理形式,限制了DTD管理XML和HTML 4,特别是“暂时的”类型,允许许多不是“合法的”XML的东西。不过,我认为它接近于编纂说明符的意图。
<!ELEMENT A - - (%inline;)* -(A) -- anchor -->
<!ENTITY % inline "#PCDATA | %fontstyle; | %phrase; | %special; | %formctrl;">
<!ENTITY % fontstyle "TT | I | B | BIG | SMALL">
<!ENTITY % phrase "EM | STRONG | DFN | CODE | SAMP | KBD | VAR | CITE | ABBR | ACRONYM" >
<!ENTITY % special "A | IMG | OBJECT | BR | SCRIPT | MAP | Q | SUB | SUP | SPAN | BDO">
<!ENTITY % formctrl "INPUT | SELECT | TEXTAREA | LABEL | BUTTON">
我将把这个层次结构中列出的标签解释为允许的标签总数。
虽然规范可能会说“内联元素”,但我非常确定,它并没有打算通过将块元素的显示类型声明为内联来绕过这个意图。无论您如何滥用内联标记,它们都具有不同的语义。
另一方面,我发现包含special似乎允许嵌套A元素是很有趣的。规范中可能有一些强硬的措辞禁止这样做,即使它在xml语法上是正确的,但我不会进一步讨论这个问题,因为这不是问题的主题。