Detailed explanation of a perfect HTML parsing engine (Jumony)

Perhaps many people will think that the current HTML parser is enough, and even simple regular expressions can already meet the needs of manipulating HTML documents. Yes, for the vast majority of HTML documents on the Internet, in fact, most of them meet the XHTML specifications, and their parsing does not require a powerful parser. But a powerful parser is one thing, and a perfect parser is another.

Jumony Core first provides a nearly perfect HTML parsing engine, and its parsing results are infinitely close to those of the browser. Whether it is elements without end tags, elements with optional end tags, tag attributes, or CSS selectors and styles, all legal and illegal HTML documents will be parsed by the browser, and Jumony will parse them into whatever they are. Sample. In other words, the results of Jumony parsing are the same as the results of browser parsing, so you no longer have to worry about whether the HTML document can be recognized. If the browser can read it, Jumony can understand it.

There is only one step between perfection and power, but a perfect parser allows you to never have to care about the HTML source document.

The following is an incomplete list of features supported by the Jumony parser

Not only can it parse HTML from text, Jumony's API can directly grab documents for analysis from the Internet, and automatically identify encodings based on HTTP headers:

new JumonyParser().LoadDocument( "www.php.cn/" ).Find( ".post_item a.titlelnk" )

It is currently second only to Jumony The HTML parsing open source project HtmlAgilityPack has stopped updating for a long time. After so many years, there are still problems with the parsing of the most basic

elements.

2. CSS style setting support

Just perfectly parsing HTML does not bring much benefit. As mentioned above, in fact, most HTML documents can be parsed with second-rate parsing. It can analyze even simple regular expressions, so why do we need Jumony?

The answer is that an HTML engine is more than just parsing the DOM structure.

Consider this scenario: I need to set a none value to the display style of an element. In the browser, we only need a simple element.style.display = "none" to meet our requirements. Now, we have obtained the DOM we need through the parser, but do we still need to concatenate strings to set the style?

No need, Jumony supports CSS style parsing, and even some CSS style abbreviation rules can be recognized. In Jumony, setting a style for an element is as simple as in the browser:

element.Style( "display", "none" )

We Let's look at this example again:

new JumonyParser().LoadDocument( "www.php.cn/" ).Find( ".post_item a.titlelnk" )

 foreach( var title = new JumonyParser().LoadDocument( "www.php.cn/" ).Find( ".post_item a.titlelnk" ) )
  Console.WriteLine( title.InnerText() );

特性	例子
孤立的<解析为文本	< a应当解析为< a
孤立的>解析为文本	>应当解析为>
标记属性（没有值的属性）
元素丢失结束标签	测试链接
可选结束标签元素 "body", "colgroup", "dd", "dt", "head", "html", "li", "option", "p", "tbody", "td", "tfoot", "th", "thead", "tr"	abc 123
无结束标签元素 "area", "base", "basefont", "br", "col", "frame", "hr", "img", "input", "isindex", "link", "meta" , "param", "wbr", "bgsound", "spacer", "keygen"
CDataElement	##
"script", "style", "textarea", "title"
Preformatted elements	There is a space in front
Use single quotes for attribute values
HTMLDeclaration

1. Free html online video tutorial

html development manual

php.cn original html5 video tutorial

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