下载地址：https://github.com/samacs/simple_html_dom
文档地址 http://simplehtmldom.sourceforge.net/
一直以来使用php解析html文档树都是一个难题。Simple HTML DOM parser 帮我们很好地解决了这个问题。可以通过这个php类来解析html文档，对其中的html元素进行操作 (PHP5+以上版本)。
解析器不仅仅只是帮助我们验证html文档；更能解析不符合W3C标准的html文档。它使用了类似jQuery的元素选择器，通过元素的id，class，tag等等来查找定位；同时还提供添加、删除、修改文档树的功能。当然，这样一款强大的html Dom解析器也不是尽善尽美；在使用的过程中需要十分小心内存消耗的情况。不过，不要担心；本文中，笔者在最后会为各位介绍如何避免消耗过多的内存。
安装：下载后把simple_html_dom.php 引入即可。
开始使用
上传类文件以后，有三种方式调用这个类：
从url中加载html文档
从字符串中加载html文档
从文件中加载html文档
// Create a DOM object
$html = new simple_html_dom();
// Load HTML from a string
$html->load('<html><body>Hello!</body></html>');
// Load HTML from a URL
$html->load_file('http://www.google.com/');
// Load HTML from a HTML file
$html->load_file('test.htm');
如果从url加载html文档，需要先从网络上下载。建议使用cURL来抓取html文档并加载DOM中。
api文档http://simplehtmldom.sourceforge.net/manual_api.htm
| Name | Description |
|---|---|
|
void
__construct ( [string $filename] ) |
Constructor, set the filename parameter will automatically load the contents, either text or file/url. |
|
string
plaintext |
Returns the contents extracted from HTML. |
|
void
clear () |
Clean up memory. |
|
void
load ( string $content ) |
Load contents from a string. |
|
string
save ( [string $filename] ) |
Dumps the internal DOM tree back into a string. If the $filename is set, result string will save to file. |
|
void
load_file ( string $filename ) |
Load contents from a from a file or a URL. |
|
void
set_callback ( string $function_name ) |
Set a callback function. |
|
mixed
find ( string $selector [, int $index] ) |
Find elements by the CSS selector. Returns the Nth element object if index is set, otherwise return an array of object. |
//查找a
foreach($html->find('a') as $elem)
{
echo $elem->href.'-->'.$elem->innertext.'<br/>';
}
$ret = $html->find('a', 0);
// Find lastest anchor, returns element object or null if not found (zero based)
$ret = $html->find('a', -1);
// Find all <div> with the id attribute
$ret = $html->find('div[id]');
// Find all <div> which attribute id=foo
$ret = $html->find('div[id=foo]'); 类似jquery属性过滤器
$ret = $html->find('#foo');
// Find all element which class=foo
$ret = $html->find('.foo');
// Find all element has attribute id
$ret = $html->find('*[id]');
($product=$table->find("#product *[selected]",0)->innertext ; )不能写成#product[selected].
// Find all anchors and images
$ret = $html->find('a, img');
// Find all anchors and images with the "title" attribute
$ret = $html->find('a[title], img[title]');
$es = $html->find('ul li');
// Find Nested <div> tags
$es = $html->find('div div div');
// Find all <td> in <table> which class="hello"
$es = $html->find('table.hello td');
// Find all td tags with attribite align=center in table tags
$es = $html->find(''table td[align=center]');
| Attribute Name | Usage |
|---|---|
| $e->tag | Read or write the tag name of element. |
| $e->outertext | Read or write the outer HTML text of element. |
| $e->innertext | Read or write the inner HTML text of element. |
| $e->plaintext | Read or write the plain text of element. |
$html = str_get_html("<div>foo <b>bar</b></div>");
$e = $html->find("div", 0);
echo $e->tag; // Returns: " div"
echo $e->outertext; // Returns: " <div>foo <b>bar</b></div>"
echo $e->innertext; // Returns: " foo <b>bar</b>"
echo $e->plaintext; // Returns: " foo bar"
| Method | Description |
|---|---|
|
mixed
$e->children ( [int $index] ) |
Returns the Nth child object if index is set, otherwise return an array of children. |
|
element
$e->parent () |
Returns the parent of element. |
|
element
$e->first_child () |
Returns the first child of element, or null if not found. |
|
element
$e->last_child () |
Returns the last child of element, or null if not found. |
|
element
$e->next_sibling () |
Returns the next sibling of element, or null if not found. |
|
element
$e->prev_sibling () |
Returns the previous sibling of element, or null if not found. |
echo $html->find("#div1", 0)->children(1)->children(1)->children(2)->id;
// or
echo $html->getElementById("div1")->childNodes(1)->childNodes(1)->childNodes(2)->getAttribute('id');
如何自定义解析行为?回调函数
function my_callback($element) {
// Hide all <b> tags
if ($element->tag=='b')
$element->outertext = '';
}
// Register the callback function with it's function name
$html->set_callback('my_callback');
// Callback function will be invoked while dumping
echo $html;