แนะนำ PHP Simple HTML DOM Parser สำหรับ ดึงข้อมูล เฉพาะส่วนท คอร์สเรียน เรียนฟรี ออนไลน์ บทความ

php class ตัวนี้ เหมาะสำหรับใช้งาน ในการค้นหา และดึงข้อมูล จาก แท็ก HTML เฉพาะส่วนที่ต้องการ เช่น

อ่านวิธีการใช้งานแบบละเอียดเพิ่มเติมได้ด้วยตัวเองได้ที่
http://simplehtmldom.sourceforge.net/manual.htm

แนะนำให้โหลดเก็บไว้ใช้งาน รวมทั้งบันทึกวิธีการใช้งานไว้ด้วย

PHP Simple HTML DOM Parser

Index

How to create HTML DOM object?
How to find HTML elements?
How to access the HTML element's attributes?
How to traverse the DOM tree?
How to dump contents of DOM object?
How to customize the parsing behavior?
API Reference
FAQ

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How to create HTML DOM object?

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Quick way
Object-oriented way

// 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');

// 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');

How to find HTML elements?

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Basics
Advanced
Descendant selectors
Nested selectors
Attribute Filters
Text & Comments

// 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 all <div> which attribute id=foo
$ret = $html->find('div[id=foo]');

// Find all <div> with the id attribute
$ret = $html->find('div[id]');

// Find all element has attribute id
$ret = $html->find('[id]');

// Find all element which id=foo
$ret = $html->find('#foo');

// Find all element which class=foo
$ret = $html->find('.foo');

// 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]');

Supports these operators in attribute selectors:

Filter	Description
[attribute]	Matches elements that have the specified attribute.
[attribute=value]	Matches elements that have the specified attribute with a certain value.
[attribute!=value]	Matches elements that don't have the specified attribute with a certain value.
[attribute^=value]	Matches elements that have the specified attribute and it starts with a certain value.
[attribute$=value]	Matches elements that have the specified attribute and it ends with a certain value.
[attribute*=value]	Matches elements that have the specified attribute and it contains a certain value.

// Find all <li> in <ul>
$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]');

// Find all text blocks
$es = $html->find('text');

// Find all comment () blocks
$es = $html->find('comment');

// 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);

How to access the HTML element's attributes?

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Get, Set and Remove attributes
Magic attributes
Tips

// 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!';

// 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"

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.

// 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;

How to traverse the DOM tree?

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Background Knowledge
Traverse the DOM tree

// 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');

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.

How to dump contents of DOM object?

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Quick way
Object-oriented way

// Dumps the internal DOM tree back into string
$str = $html->save();

// Dumps the internal DOM tree back into a file
$html->save('result.htm');

// Dumps the internal DOM tree back into string
$str = $html;

// Print it!
echo $html;

How to customize the parsing behavior?

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Callback function

// 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;

Author: S.C. Chen (me578022@gmail.com)
Original idea is from Jose Solorzano's HTML Parser for PHP 4.
Contributions by: Yousuke Kumakura (Attribute Filters)

แนะนำ PHP Simple HTML DOM Parser สำหรับ ดึงข้อมูล เฉพาะส่วนที่ต้องการ

html dom parser php

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