Using preg_match_all is it possible to match elements within a parent that has a specific class name?
For example I have this HTML markup:
<div class="red lorem-ipsum>
Some link
</div>
<div class="red>
Some link
</div>
<div class="something red lorem-ipsum>
Some link
</div>
Can I match each <a> that's within a parent with class name red?
I tried this but it does not work:
~(?:<div class="red">|\G)\s*<a [^>]+>~i
Use DOMDocument in combination with DOMXPath. Here the HTML is in the $html variable:
$doc = new DOMDocument();
$doc->loadHTML($html);
$xpath = new DOMXPath($doc);
$matches = $xpath->query("//div[contains(concat(' ', #class, ' '), ' red ')]/a");
foreach($matches as $a) {
echo $a->textContent;
}
Related
I am using Nette PHP (framework shouldn't matter), and I'm trying to replace parts of html with different one - if image tag has class=, it will be replaced with class="image-responsive, and if not it will get a new attribute class="image-responsive".
I'm getting that HTML as a string, which will be saved in database!
This is my current code. It can find the strings, but what I need help with is replacing parts of the html.
public static function ImageAddClass($string)
{
// Match Img with class="$1 (group 1 here)"
$regex_img = '/(<img)([^>]*[^>]*)(\/>)/mi';
$regex_imgClass = '/(<img[^>]* )(class=\")([^\"]*\"[^>]*>)/mi';
$html = $string;
if (preg_match_all($regex_img, $html, $matches)) {
for ($x = 0; $x < count($matches[0]); $x++) {
bdump($matches[0]);
bdump($matches[0][$x]);
bdump($x);
if (preg_match($regex_imgClass, $matches[0][$x])) {
$html = preg_replace($regex_imgClass, '$1class="image-responsiveO $3', $html);
} else if (preg_match($regex_img, $matches[0][$x])) {
$html = preg_replace($regex_img, '$1 class="image-responsiveN" $2$3', $html);
}
}
return $html;
}
}
Covering all scenarios where an img tag might have no class attribute, an orphaned class attribute, a blank class attribute, a class attribute with one or more other words, and a class attribute that already contains image-responsive -- I prefer to use XPath to filter the elements.
Not only is parsing HTML with a legitimate DOM parser like DOMDocument more robust/reliable than regex, the accompanying XPath syntax is highly intuitive.
Pay close attention to how the XPath query pads the haystack class and the needle class with spaces as a means to ensure whole word matching.
Any images that are iterated will have the desired value added to the element's class attribute.
Code: (Demo)
$html = <<<HTML
<div>
<img src="">
<img src="" class>
<img src="" class="image-responsive">
<img src="" class="">
<img src="image-responsive" class="classy">
<img src="" class="image-responsiveness">
<span class='NOT-responsive'></span>
<img src="" class = "foo image-responsive">
</div>
HTML;
$dom = new DOMDocument;
$dom->loadHTML($html, LIBXML_HTML_NOIMPLIED | LIBXML_HTML_NODEFDTD);
$xpath = new DOMXPath($dom);
foreach ($xpath->query('//img[not(contains(concat(" ", #class, " ")," image-responsive "))]') as $img) {
$img->setAttribute('class', ltrim($img->getAttribute('class') . ' image-responsive'));
}
echo $dom->saveHTML();
Output:
<div>
<img src="" class="image-responsive">
<img src="" class="image-responsive">
<img src="" class="image-responsive">
<img src="" class="image-responsive">
<img src="image-responsive" class="classy image-responsive">
<img src="" class="image-responsiveness image-responsive">
<span class="NOT-responsive"></span>
<img src="" class="foo image-responsive">
</div>
Related content:
Replace empty alt in wordpress post content with filter
Xpath syntax for "and not contains"
Parsing HTML with PHP To Add Class Names
How can I match on an attribute that contains a certain string?
As a slight variation, you can access all img tags without XPath, then use preg_match() calls to determine which tags should receive the new class. The word boundary character \b is not useful in this case because class names may contain non-word characters.
Code: (Demo)
$dom = new DOMDocument;
$dom->loadHTML($html, LIBXML_HTML_NOIMPLIED | LIBXML_HTML_NODEFDTD);
$xpath = new DOMXPath($dom);
foreach ($dom->getElementsByTagName('img') as $img) {
$class = $img->getAttribute('class');
if (!preg_match('/(?:^| )image-responsive(?: |$)/', $class)) {
$img->setAttribute('class', ltrim("$class image-responsive"));
}
}
echo $dom->saveHTML();
// same output as first snippet
i am trying to get specific HTML code portion with regex preg_match_all by matching it with class tag But it is returning empty array.
This is the html portion which i want to get from complete HTML
<div class="details">
<div class="title">
<a href="citation.cfm?id=2892225&CFID=598850954&CFTOKEN=15595705"
target="_self">Restrictification of function arguments</a>
</div>
</div>
Where I am using this regex
preg_match_all('~<div class=\'details\'>\s*(<div.*?</div>\s*)?(.*?)</div>~is', $html, $matches );
NOTE: $html variable is having the whole html from which I want to search.
Thanks.
You are looking for single quotes in your regex in contrast to the double quotes in $html.
Your regex should look like:
'~<div class="details">\s*(<div.*?</div>\s*)?(.*?)</div>~is'
or better:
'~<div class=[\'"]details[\'"]>\s*(<div.*?</div>\s*)?(.*?)</div>~is'
Better use a DOM approach !
<?php
$html = '<div class="details">
<div class="title">
<a href="citation.cfm?id=2892225&CFID=598850954&CFTOKEN=15595705"
target="_self">Restrictification of function arguments</a>
</div>
</div>';
$doc = new DOMDocument();
$doc->loadHTML($html);
$xpath = new DOMXpath($doc);
$divs = $xpath->query('//div[#class="title"]');
print_r($divs);
?>
I have layout like this:
<div class="fly">
<img src="a.png" class="badge">
<img class="aye" data-original="b.png" width="130" height="253" />
<div class="to">
<h4>Fly To The Moon</h4>
<div class="clearfix">
<div class="the">
<h4>**Wow**</h4>
</div>
<div class="moon">
<h4>**Great**</h4>
</div>
</div>
</div>
</div>
First I get query from xpath :
$a = $xpath->query("//div[#class='fly']""); //to get all elements in class fly
foreach ($a as $p) {
$t = $p->getElementsByTagName('img');
echo ($t->item(0)->getAttributes('data-original'));
}
When I run the code, it will produced 0 result. After I trace I found that <img class="badge"> is processed first. I want to ask, how can I get data-original value from <img class="aye">and also get the value "Wow" and "Great" from <h4> tag?
Thank you,
Alernatively, you could use another xpath query on that to add on your current code.
To get the attribute, use ->getAttribute():
$dom = new DOMDocument();
$dom->loadHTML($markup);
$xpath = new DOMXpath($dom);
$parent_div = $xpath->query("//div[#class='fly']"); //to get all elements in class fly
foreach($parent_div as $div) {
$aye = $xpath->query('./img[#class="aye"]', $div)->item(0)->getAttribute('data-original');
echo $aye . '<br/>'; // get the data-original
$others = $xpath->query('./div[#class="to"]/div[#class="clearfix"]', $div)->item(0);
foreach($xpath->query('./div/h4', $others) as $node) {
echo $node->nodeValue . '<br/>'; // echo the two h4 values
}
echo '<hr/>';
}
Sample Output
Thank you for your code!
I try the code but it fails, I don't know why. So, I change a bit of your code and it works!
$dom = new DOMDocument();
$dom->loadHTML($markup);
$xpath = new DOMXpath($dom);
$parent_div = $xpath->query("//div[#class='fly']"); //to get all elements in class fly
foreach($parent_div as $div) {
$aye = $xpath->query('**descendant::**img[#class="aye"]', $div)->item(0)->getAttribute('data-original');
echo $aye . '<br/>'; // get the data-original
$others = $xpath->query('**descendant::**div[#class="to"]/div[#class="clearfix"]', $div)->item(0);
foreach($xpath->query('.//div/h4', $others) as $node) {
echo $node->nodeValue . '<br/>'; // echo the two h4 values
}
echo '<hr/>';
}
I have no idea what is the difference between ./ and descendant but my code works fine using descendant.
given the following XML:
<div class="fly">
<img src="a.png" class="badge">
<img class="aye" data-original="b.png" width="130" height="253" />
<div class="to">
<h4>Fly To The Moon</h4>
<div class="clearfix">
<div class="the">
<h4>**Wow**</h4>
</div>
<div class="moon">
<h4>**Great**</h4>
</div>
</div>
</div>
</div>
you asked:
how can I get data-original value from <img class="aye">and also get the value "Wow" and "Great" from <h4> tag?
With XPath you can obtain the values as string directly:
string(//div[#class='fly']/img/#data-original)
This is the string from the first data-original attribute of an img tag within all divs with class="fly".
string(//div[#class='fly']//h4[not(following-sibling::*//h4)][1])
string(//div[#class='fly']//h4[not(following-sibling::*//h4)][2])
These are the string values of first and second <h4> tag that is not followed on it's own level by another <h4> tag within all divs class="fly".
This looks a bit like standing in the way right now, but with iteration, those parts in front will not be needed any longer soon because the xpath then will be relative:
//div[#class='fly']
string(./img/#data-original)
string(.//h4[not(following-sibling::*//h4)][1])
string(.//h4[not(following-sibling::*//h4)][2])
To use xpath string(...) expressions in PHP you must use DOMXPath::evaluate() instead of DOMXPath::query(). This would then look like the following:
$aye = $xpath->evaluate("string(//div[#class='fly']/img/#data-original)");
$h4_1 = $xpath->evaluate("string(//div[#class='fly']//h4[not(following-sibling::*//h4)][1])");
$h4_2 = $xpath->evaluate("string(//div[#class='fly']//h4[not(following-sibling::*//h4)][2])");
A full example with iteration and output:
// all <div> tags with class="fly"
$divs = $xpath->evaluate("//div[#class='fly']");
foreach ($divs as $div) {
// the first data-original attribute of an <img> inside $div
echo $xpath->evaluate("string(./img/#data-original)", $div), "<br/>\n";
// all <h4> tags anywhere inside the $div
$h4s = $xpath->evaluate('.//h4[not(following-sibling::*//h4)]', $div);
foreach ($h4s as $h4) {
echo $h4->nodeValue, "<br/>\n";
}
}
As the example shows, you can use evaluate as well for node-lists, too. Obtaining the values from all <h4> tags it not with string() any longer as there could be more than just two I assume.
Online Demo including special string output (just exemplary):
echo <<<HTML
{$xpath->evaluate("string(//div[#class='fly']/img/#data-original)")}<br/>
{$xpath->evaluate("string(//div[#class='fly']//h4[not(following-sibling::*//h4)][1])")}<br/>
{$xpath->evaluate("string(//div[#class='fly']//h4[not(following-sibling::*//h4)][2])")}<br/>
<hr/>
HTML;
i have this html from stagram :
<div id="photo351321902758808423_176859145" class="photoeach">
<div class="photoeachinner">
<div class="left">
<div class="photowrapper">
<div class="infomation_box clearfix">
<div class="profimage_small">
<div id="photo351295515670923844_176859145" class="photoeach">
<div class="photoeachinner">
<div class="left">
<div class="photowrapper">
<div class="infomation_box clearfix">
i need find class photoeach and extract id 352034826703915686_176859145
i did with regex but no luck , so im trying do it with domdocument
i followed step from
Getting DOM elements by classname
$dom = new DomDocument();
$dom->load($filePath);
$finder = new DomXPath($dom);
$classname="photoeach";
$nodes = $finder->query("//*[contains(#class, '$classname')]");
but i cant firgure it out how i can extract ID
As Dave already mentioned you are not really that far off:
$dom = new DomDocument();
$dom->load($filePath);
$finder = new DomXPath($dom);
$classname="photoeach";
$nodes = $finder->query("//*[#class = '$classname']");
foreach ($nodes as $node) {
echo 'Id: ' , substr($node->getAttribute('id'), 5) , '<br>';
}
Demo: http://codepad.viper-7.com/xEdYLr
Note that I have changed the contains selector of the class to only match exact matches, otherwise the photoeachinner would also be matched. If this is not what you want you can easily revert that change.
I have this HTML code:
<div class ="lvlone">
<div class = "lvltwo"> Hello
<span>World</span>
</div>
</div>
I do this:$res = $xpath->query(//div[#class='lvlone']/div[#class='lvltwo']);
I get Hello World including the string in <span> tag but i down want it!
I only want the Hello.
What can i do ?
Thanks!
As TheZ points out, you can use the text() function from XPath:
$nodes = $xpath->query( '//div[#class="lvltwo"]/text()');
echo $nodes->item(0)->nodeValue; // Prints 'Hello'