Cool HTML Parser

Top 10 Best Usage Examples of PHP Simple HTML DOM Parser

Simple HTML DOM Parser is one of the best things that has happened to me. I remember the days when I used to use regular expressions and preg_match_all function to fetch values from scraped text, they were not so good. But ever since I found this HTML DOM Parser, life has been way too easy when it comes to fetching data and extracting values from html pages.

During my initial days while using this script, I was confused quite a lot of times. The parser is actually so awesome that it provides too many features and it can do almost everything you would want a parser to do. Only problem is to remember the syntax and method of calling various functions along with numerous distinct parameters for each of them.

I’ve made a list of codes, which I use from time to time, that can come in handy for you all. Read further to understand the usage of Simple HTML DOM Parser and get readymade PHP codes for the same.

Downloading and storing structured data

Data can be obtained from mainly three different sources : URL, Static File or HTML String. Use the following code to create a DOM from three different alternatives.

PHP Simple HTML DOM Parser
PHP Simple HTML DOM Parser is the best HTML DOM parser in any programming language.
"); //to fetch a webpage in a string and then parse $data = file_get_contents("http://nimishprabhu.com"); //or you can use curl too, like me :) // Some manipulation with the $data variable, for e.g. $data = str_replace("Nimish", "NIMISH", $data); //now parsing it into html $html = str_get_html($data); ?>

Finding HTML elements based on their tag names

Suppose you wanted to find each and every image on a webpage or say, each and every hyperlink. We will be using “find” function to extract this information from the object. Here’s how to do it using Simple HTML DOM Parser :

find('a') as $a) < $links[] = $a->href; > print_r($links); //to fetch all images from a webpage $images = array(); foreach($html->find('img') as $img) < $images[] = $img->src; > print_r($images); //to find h1 headers from a webpage $headlines = array(); foreach($html->find('h1') as $header) < $headlines[] = $header->plaintext; > print_r($headlines); ?>

Extracting values of attributes from elements

Suppose you want to get names of all input fields on a webpage, let’s say for e.g., http://nimishprabhu.com/chrome-extension-hello-world-example.html. Now if you see the webpage you will notice that there is a comment form on the page which has input fields. Please note that the comment box is a textarea element and not input element, so it will not be detected. But to detect rest of the visible as well has hidden fields you can use following code :

find('input') as $input) < echo $input->name.'
'; > // Output for above script : // author // email // url // submit // comment_post_ID // comment_parent ?>

Filtering elements based on values of its attributes

When a developer designs a page, he uses various attributes to uniquely identify and classify the information on the webpage. A parser is not human and hence cannot visualize the difference, but it can detect these attributes and filter the output so as to obtain a precise set of data. Let us take a practical example for better understanding. If you see this page : https://www.phpbb.com/community/viewtopic.php?f=46&t=543171 you can see the page is divided into header, content and footer. Now even the content is further sub divided into posts. This page has only 1 post but I decided to choose this as it contains quite a lot of hyperlinks. Now suppose you wanted to extract only the hyperlinks in the post and not the entire page. The approach should be as follows : Check the source of the webpage. Find out whether the hyperlinks are following some kind of pattern. If you look closely you will find that all of them have This will make extracting them, a piece of cake. Read the code below to see how to filter html elements based on values of attributes.

find('a[class="postlink"]') as $a) < $links[] = $a->href; > print_r($links); ?>

There is something worth noting here, you can use “.” and “#” prefixes to filter class and id attributes respectively. So the above code will work without any change if you use the filter as :

foreach($html->find('a.postlink') as $a)

Pattern matching while filtering attributes of elements

Consider the above example where we are extracting all links from the post. Say you want to find only the links of the sub forums in the community. If you notice all of them begin with http://www.phpbb.com/community/viewforum.php. So let’s filter the hyperlinks using “starts with” filter to fetch only the links starting with http://www.phpbb.com/community/viewforum.php

find('a[href^="http://www.phpbb.com/community/viewforum.php"]') as $a) < $links[] = $a->href; > print_r($links); ?>

Similarly, say if you want to find all links containing phpbb.com then you can filter using “contains” filter as follows :

foreach($html->find('a[href*="phpbb.com"]') as $a)

If you are sure about only the end part of the value of an attribute. Let’s say, for e.g., you are scrapping a webpage which contains numerous div elements. These div elements have the id attribute something like :

foreach($html->find('div[id$="_message_id"]' as $div)

find('a.postlink') as $a) < $a->class = 'topiclink'; > echo $html; ?>

$html->find('div#content',0)->innertext = '';

$appendcode = '
This is the text to append to existing innertext
'; $html->find('div#content',0)->innertext .= $appendcode;

$prependcode = '
Nice article below
'; $html->find('div#content,0)->innertext = $prependcode . $html->find('div#content',0)->innertext;

$html->find('div#content',0)->outertext = '
find('div#content',0)->outertext. '
';

МВО 
МВО - масловодоотталкивающая отделка
 
Благодаря масловодоотталкивающей отделке ткань препятствует проникновению воды и жировых, масляных жидкостей, сохраняя при этом воздухо- (паро- ) проницаемость ( ткань пропускает пары пота). Тестирование проводится нанесением тестирующих жидкостей по методике ф. "3М".
 
 '; $output = array(); $doc = new DomDocument(); $doc->loadHTML('' . $html); /* Корректно обрабатываем UTF-8 */ // dirty fix foreach ($doc->childNodes as $item) if ($item->nodeType == XML_PI_NODE) $doc->removeChild($item); // remove hack $doc->encoding = 'UTF-8'; // insert proper $urls = $doc->getElementsByTagName('a'); foreach ($urls as $url) < if ($url->getAttribute('class') === 'seq') < $childs = $url->getElementsByTagName('*'); foreach ($childs as $child) < $url->removeChild($child); > $output[] = trim($url->nodeValue); > > print_r($output);