Simple HTML DOM 简单的 PHP DOM 解析器
Simple HTML DOM 是一个简单的 PHP DOM 解析器，可以想 jQuery 一样操作 HTML 元素，查找和替换网页的内容，并且支持不规范的 HTML 标签，最低版本要求 PHP5+。
特点
- 用 PHP5+编写的 HTML DOM 解析器可以让您以非常简单的方式操作 HTML 文档。
- 要求 PHP 5+
- 支持无效的 HTML。
- 在 HTML 页面上查找带有选择器的标记，如下所示 jQuery 。
- 在一行中从HTML中提取内容。
使用方法
通过文件获取元素
// Create DOM from URL or file
$html = file_get_html('http://www.google.com/');
// Find all images
foreach($html->find('img') as $element)
echo $element->src . '
';
// Find all links
foreach($html->find('a') as $element)
echo $element->href . '
';修改 HTML 内容
// Create DOM from string
$html = str_get_html('<div id="hello">Hello</div><div id="world">World</div>');
$html->find('div', 1)->class = 'bar';
$html->find('div[id=hello]', 0)->innertext = 'foo';
echo $html; // Output: <div id="hello">foo</div><div id="world" class="bar">World</div>提取文本
// Dump contents (without tags) from HTML
echo file_get_html('http://www.google.com/')->plaintext;综合示例
// Create DOM from URL
$html = file_get_html('http://slashdot.org/');
// Find all article blocks
foreach($html->find('div.article') as $article) {
$item['title'] = $article->find('div.title', 0)->plaintext;
$item['intro'] = $article->find('div.intro', 0)->plaintext;
$item['details'] = $article->find('div.details', 0)->plaintext;
$articles[] = $item;
}
print_r($articles);如何创建 HTML DOM 对象？
快速方式
// Create a DOM object from a string
$html = str_get_html('<html><body>Hello!</body></html>');
// Create a DOM object from a URL
$html = file_get_html('http://www.google.com/');
// Create a DOM object from a HTML file
$html = file_get_html('test.htm');面向对象
// 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');如何找到 HTML 元素？
基本用法
// Find all anchors, returns a array of element objects
$ret = $html->find('a');
// Find (N)th anchor, returns element object or null if not found (zero based)
$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]');高级用法
// Find all element which id=foo
$ret = $html->find('#foo');
// Find all element which class=foo
$ret = $html->find('.foo');
// Find all element has attribute id
$ret = $html->find('*[id]');
// Find all anchors and images
$ret = $html->find('a, img');
// Find all anchors and images with the "title" attribute
$ret = $html->find('a[title], img[title]');后代选择器
// Find all <li> in <ul>
foreach($html->find('ul') as $ul)
{
foreach($ul->find('li') as $li)
{
// do something...
}
}
// Find first <li> in first <ul>
$e = $html->find('ul', 0)->find('li', 0);嵌套选择器
// Find all <li> in <ul>
foreach($html->find('ul') as $ul)
{
foreach($ul->find('li') as $li)
{
// do something...
}
}
// Find first <li> in first <ul>
$e = $html->find('ul', 0)->find('li', 0);属性过滤器
在属性选择器中支持这些运算符：
| 滤光器 | 描述 |
|---|---|
| [属性] | 匹配以下元素有指定的属性。 |
| [!属性] | 匹配以下元素没有指定的属性。 |
| [属性=值] | 将具有指定属性的元素与一定值. |
| [属性!=值] | 匹配以下元素没有具有特定值的指定属性。 |
| [属性^=值] | 匹配具有指定属性的元素开始有某个值。 |
| [属性$=值] | 匹配具有指定属性的元素端部有某个值。 |
| [属性*=值] | 匹配具有指定属性的元素含某个值。 |
文本和评论
// Find all text blocks
$es = $html->find('text');
// Find all comment (<!--...-->) blocks
$es = $html->find('comment');如何访问HTML元素的属性？
获取、设置和删除属性
// Get a attribute ( If the attribute is non-value attribute (eg. checked, selected...), it will returns true or false)
$value = $e->href;
// Set a attribute(If the attribute is non-value attribute (eg. checked, selected...), set it's value as true or false)
$e->href = 'my link';
// Remove a attribute, set it's value as null!
$e->href = null;
// Determine whether a attribute exist?
if(isset($e->href))
echo 'href exist!';魔术属性
// Example
$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"| 属性名 | 使用 |
|---|---|
| $e->tag | 读或写标签名元素。 |
| $e->outertext | 读或写外部HTML文本元素。 |
| $e->innertext | 读或写内部HTML文本元素。 |
| $e->plaintext | 读或写纯文本元素。 |
小贴士
// Extract contents from HTML
echo $html->plaintext;
// Wrap a element
$e->outertext = '<div class="wrap">' . $e->outertext . '<div>';
// Remove a element, set it's outertext as an empty string
$e->outertext = '';
// Append a element
$e->outertext = $e->outertext . '<div>foo<div>';
// Insert a element
$e->outertext = '<div>foo<div>' . $e->outertext;如何遍历 DOM 树？
Background Knowledge
// If you are not so familiar with HTML DOM, check this link to learn more...
// Example
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');转换树结构
You can also call methods with Camel naming convertions.
| 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. |
如何转储DOM对象的内容？
快速方式
// Dumps the internal DOM tree back into string
$str = $html;
// Print it!
echo $html;面向对象
// Dumps the internal DOM tree back into string
$str = $html->save();
// Dumps the internal DOM tree back into a file
$html->save('result.htm');如何自定义解析行为？
回调函数
// Write a function with parameter "$element"
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;API Reference
Helper functions
| Name | Description |
|---|---|
| objectstr_get_html ( string $content ) | Creates a DOM object from a string. |
| objectfile_get_html ( string $filename ) | Creates a DOM object from a file or a URL. |
DOM methods & properties
| 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. |
Element methods & properties
| Name | Description |
|---|---|
| string [attribute] | Read or write element's attribure value. |
| string tag | Read or write the tag name of element. |
| string outertext | Read or write the outer HTML text of element. |
| string innertext | Read or write the inner HTML text of element. |
| string plaintext | Read or write the plain text of element. |
| mixed find ( string $selector [, int $index] ) | Find children by the CSS selector. Returns the Nth element object if index is set, otherwise, return an array of object. |
DOM traversing
| Name | 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. |
Camel naming convertions
You can also call methods with W3C STANDARD camel naming convertions.
| Method | Mapping |
|---|---|
| array $e->getAllAttributes () | array $e->attr |
| string $e->getAttribute ( $name ) | string $e->attribute |
| void $e->setAttribute ( $name, $value ) | void $value = $e->attribute |
| bool $e->hasAttribute ( $name ) | bool isset($e->attribute) |
| void $e->removeAttribute ( $name ) | void $e->attribute = null |
| element $e->getElementById ( $id ) | mixed $e->find ( "#$id", 0 ) |
| mixed $e->getElementsById ( $id [,$index] ) | mixed $e->find ( "#$id" [, int $index] ) |
| element $e->getElementByTagName ($name ) | mixed $e->find ( $name, 0 ) |
| mixed $e->getElementsByTagName ( $name [, $index] ) | mixed $e->find ( $name [, int $index] ) |
| element $e->parentNode () | element $e->parent () |
| mixed $e->childNodes ( [$index] ) | mixed $e->children ( [int $index] ) |
| element $e->firstChild () | element $e->first_child () |
| element $e->lastChild () | element $e->last_child () |
| element $e->nextSibling () | element $e->next_sibling () |
| element $e->previousSibling () | element $e->prev_sibling () |
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