小试QueryPath，一个实现了不少jQuery接口的PHP类库
很想写一个PHP的jQuery，但是自己精力与能力有限，于是Google一下，找到 QueryPath。
其实前几天已经找到一个，叫 simple_html_dom (SourceForge下载)，不到1000行代码，很简单。有兴趣就下载看看。
基本使用方法：
require 'src/QueryPath/QueryPath.php';
// 解释HTML为DOM
qp('<html>...</html>');
// 或者加载文件
qp('http://www.google.com.hk/index.html');
// 解释HTML为DOM
qp('<html>...</html>');
// 或者加载文件
qp('http://www.google.com.hk/index.html');
如果 qp的第一个参数是 url（包括http、file），则需要以html或htm为后缀名，否则当作XML来解释，通常会解释失败，并抛出 QueryPathExtension 异常，这应该说是一个缺陷，2.1版本的代码在QueryPath.php的3903-4010行。
有了qp返回的对象，我们就可以用 PHP 以 jQuery 类似的方法来操作DOM，如选择节点，可以用CSS3选择器、parent/top/children等函数。
下载是官方手册上的一个快速入门的例子 ：
<?php
require_once '../src/QueryPath/QueryPath.php';
// Begin with an HTML stub document (XHTML, actually), and navigate to the title.
qp(QueryPath::HTML_STUB, 'title')
// Add some text to the title
->text('Example of QueryPath.')
// Now look for the <body> element
->find(':root body')
// Inside the body, add a title and paragraph.
->append('<h1>This is a test page</h1><p>Test text</p>')
// Now we select the paragraph we just created inside the body
->children('p')
// Add a 'class="some-class"' attribute to the paragraph
->attr('class', 'some-class')
// And add a style attribute, too, setting the background color.
->css('background-color', '#eee')
// Now go back to the paragraph again
->parent()
// Before the paragraph and the title, add an empty table.
->prepend('<table id="my-table"></table>')
// Now let's go to the table...
->find('#my-table')
// Add a couple of empty rows
->append('<tr></tr><tr></tr>')
// select the rows (both at once)
->children()
// Add a CSS class to both rows
->addClass('table-row')
// Now just get the first row (at position 0)
->eq(0)
// Add a table header in the first row
->append('<th>This is the header</th>')
// Now go to the next row
->next()
// Add some data to this row
->append('<td>This is the data</td>')
// Write it all out as HTML
->writeHTML();
?>
require_once '../src/QueryPath/QueryPath.php';
// Begin with an HTML stub document (XHTML, actually), and navigate to the title.
qp(QueryPath::HTML_STUB, 'title')
// Add some text to the title
->text('Example of QueryPath.')
// Now look for the <body> element
->find(':root body')
// Inside the body, add a title and paragraph.
->append('<h1>This is a test page</h1><p>Test text</p>')
// Now we select the paragraph we just created inside the body
->children('p')
// Add a 'class="some-class"' attribute to the paragraph
->attr('class', 'some-class')
// And add a style attribute, too, setting the background color.
->css('background-color', '#eee')
// Now go back to the paragraph again
->parent()
// Before the paragraph and the title, add an empty table.
->prepend('<table id="my-table"></table>')
// Now let's go to the table...
->find('#my-table')
// Add a couple of empty rows
->append('<tr></tr><tr></tr>')
// select the rows (both at once)
->children()
// Add a CSS class to both rows
->addClass('table-row')
// Now just get the first row (at position 0)
->eq(0)
// Add a table header in the first row
->append('<th>This is the header</th>')
// Now go to the next row
->next()
// Add some data to this row
->append('<td>This is the data</td>')
// Write it all out as HTML
->writeHTML();
?>
详细请参考其官网及API手册（包含在源码中）：http://querypath.org/
QueryPath的基本特征：http://querypath.org/node/2
