Ideas and sample codes for using PHP instead of JS to play with DOM_PHP Tutorial

The origin of the matter is relatively simple. I need to organize the data of a navigation page and write it into the database. A more intuitive method is to analyze the HTML file. The common method is to use PHP regular expressions to match. However, it is difficult to develop and maintain in this way, and the code readability is very poor.

The data on the navigation page is regularly arranged in the DOM tree. It can be easily operated with several loops using JS. Moreover, JS needs to rely on the browser and it is difficult to operate the database. In fact, PHP has a ready-made class library to add, delete, modify and check nodes in the DOM tree. I will make some notes here.

There are two classes involved here: DOMDocument and DOMXPath.

In fact, the idea is relatively clear, which is to convert an html file into the data structure of a DOM tree through DOMDocument, and then use an instance of DOMXPath to search the DOM tree to get the specific node you want, and then you can Traverse the subtree of the node to get the desired result.

There is such a navigation html file "./hao.html" in the current directory

Now we need to get the Chinese content of all tags, the php code is as follows:

Copy code The code is as follows:

//Convert html/xml file into DOM tree
$dom = new DOMDocument();
$dom->loadHTMLFile("hao.html");

//Get all dl tags with class fix

// example 1: for everything with an id
//$elements = $xpath->query("//*[@id]");

// example 2: for node data in a selected id
//$elements = $xpath->query("/html/body/div[@id='yourTagIdHere']");

// example 3: same as above with wildcard
//$elements = $xpath->query("*/div[@id='yourTagIdHere']");
$xpath = new DOMXPath($dom);
$dls = $xpath->query('//dl[@class="fix"]');

foreach ($dls as $dl) {
$spans = $dl->childNodes;
foreach ($spans as $span) {
echo trim($span->textContent)."t";
}
echo "n";
}
? >

The output result is as follows:

Note: It is worth noting that the default encoding method of DOMDocument is Latin, so when processing UTF-encoded Chinese, you need to enter < head> followed by

Copy code The code is as follows:

in other locations, or just write both It's not recognized

http://www.bkjia.com/PHPjc/813508.htmlwww.bkjia.comtruehttp: //www.bkjia.com/PHPjc/813508.htmlTechArticleThe origin of the matter is relatively simple. I need to organize the data of a navigation page and write it into the database. A more intuitive method is to analyze html files. The common method is to use PHP regular...