Suppose I have a string containing some HTML. I want to remove every li tag before reaching the first p tag.
How do I achieve something like that?
Example string:
$str = "<img src='something.png'/>some_text_here<li>needs_to_be_removed</li>
<li>also_needs_to_be_removed</li>some_other_text<p>finally</p>more_text_here
<li>this_should_not_be_removed</li>";`
The first two li tags need to be removed.
here is what you need. Simple and effective:
$mystring = "mystringwith<li>toberemovedstring</li><li>againremove</li><p>do not remove me</p>";//the string you provide
$findme = '<li>';//the string you want to search in $mystring
$findpee = '<p>';//haha pee also where to end it
$pos = strpos($mystring, $findme);//first position of <li>
$pospee = strpos($mystring, $findpee);// then position of pee.. get it :)
//Then we remove it
$result=substr_replace ( $mystring ,"" , $pos, ($pospee-$pos));
echo $result;
Edit: PHP sandbox
http://sandbox.onlinephpfunctions.com/code/e534259e2312682a04b64c6e3aae1521422aacd2
you can check the result here as well
You can do it with PHP's DOMdocument using the below traversal function
$doc = new DOMDocument();
$doc->loadHTML($str);
$foundp = false;
showDOMNode($doc);
//now $doc contains the string you want
$newstr = $doc->saveHTML();
function showDOMNode(DOMNode &$domNode) {
global $foundp;
foreach ($domNode->childNodes as $node)
{
if ($node->nodeName == "li" && $foundp==false){
//delete this node
$domNode->removeChild($node);
}
else if ($node->nodeName == "p"){
//stop here
$foundp = true;
return;
}
else if($node->hasChildNodes() && $foundp==false) {
//recursively
showDOMNode($node);
}
}
}
With XPath:
$str = "<img src='something.png'/>some_text_here<li>needs_to_be_removed</li>
<li>also_needs_to_be_removed</li>some_other_text<p>finally</p>more_text_here
<li>this_should_not_be_removed</li>";
libxml_use_internal_errors(true);
$dom = new DOMDocument;
$dom->loadHTML('<div>' . $str .'</div>', LIBXML_HTML_NODEFDTD | LIBXML_HTML_NOIMPLIED);
// ^---------------^----- add a root element
$xp = new DOMXPath($dom);
$lis = $xp->query('//p[1]/preceding-sibling::li');
foreach ($lis as $li) {
$li->parentNode->removeChild($li);
}
$result = '';
// add each child node of the root element to the result
foreach ($dom->getElementsByTagName('div')->item(0)->childNodes as $child) {
$result .= $dom->saveHTML($child);
}
I would suggest using a php praser library will be much better and faster approach. I personally use this one https://github.com/paquettg/php-html-parser in my projects. it provides apis like
$child->nextSibling()
$content->innerHtml,
$content->firstChild()
and more which can come in handy.
You can just do a foreach loop for all elements, register "li" tag inside them and if for third occurance, you find a "p" tag, you can just delete the $child->previousSibling();
I have a html string that contains exactly one a-element in it. Example:
test
In php I have to test if rel contains external and if yes, then modify href and save the string.
I have looked for DOM nodes and objects. But they seem to be too much for only one A-element, as I have to iterate to get html nodes and I am not sure how to test if rel exists and contains external.
$html = new DOMDocument();
$html->loadHtml($txt);
$a = $html->getElementsByTagName('a');
$attr = $a->item(0)->attributes();
...
At this point I am going to get NodeMapList that seems to be overhead. Is there any simplier way for this or should I do it with DOM?
Is there any simplier way for this or should I do it with DOM?
Do it with DOM.
Here's an example:
<?php
$html = 'test';
$dom = new DOMDocument;
$dom->loadHTML($html);
$xpath = new DOMXPath($dom);
$nodes = $xpath->query("//a[contains(concat(' ', normalize-space(#rel), ' '), ' external ')]");
foreach($nodes as $node) {
$node->setAttribute('href', 'http://example.org');
}
echo $dom->saveHTML();
I kept going to modify with DOM. This is what I get:
$html = new DOMDocument();
$html->loadHtml('<?xml encoding="utf-8" ?>' . $txt);
$nodes = $html->getElementsByTagName('a');
foreach ($nodes as $node) {
foreach ($node->attributes as $att) {
if ($att->name == 'rel') {
if (strpos($att->value, 'external')) {
$node->setAttribute('href','modified_url_goes_here');
}
}
}
}
$txt = $html->saveHTML();
I did not want to load any other library for just this one string.
The best way is to use a HTML parser/DOM, but here's a regex solution:
$html = 'test<br>
<p> Some text</p>
test2<br>
<a rel="external">test3</a> <-- This won\'t work since there is no href in it.
';
$new = preg_replace_callback('/<a.+?rel\s*=\s*"([^"]*)"[^>]*>/i', function($m){
if(strpos($m[1], 'external') !== false){
$m[0] = preg_replace('/href\s*=\s*(("[^"]*")|(\'[^\']*\'))/i', 'href="http://example.com"', $m[0]);
}
return $m[0];
}, $html);
echo $new;
Online demo.
You could use a regular expression like
if it matches /\s+rel\s*=\s*".*external.*"/
then do a regExp replace like
/(<a.*href\s*=\s*")([^"]\)("[^>]*>)/\1[your new href here]\3/
Though using a library that can do this kind of stuff for you is much easier (like jquery for javascript)
I am using HTML Purifier (http://htmlpurifier.org/)
I just want to remove <script> tags only.
I don't want to remove inline formatting or any other things.
How can I achieve this?
One more thing, it there any other way to remove script tags from HTML
Because this question is tagged with regex I'm going to answer with poor man's solution in this situation:
$html = preg_replace('#<script(.*?)>(.*?)</script>#is', '', $html);
However, regular expressions are not for parsing HTML/XML, even if you write the perfect expression it will break eventually, it's not worth it, although, in some cases it's useful to quickly fix some markup, and as it is with quick fixes, forget about security. Use regex only on content/markup you trust.
Remember, anything that user inputs should be considered not safe.
Better solution here would be to use DOMDocument which is designed for this.
Here is a snippet that demonstrate how easy, clean (compared to regex), (almost) reliable and (nearly) safe is to do the same:
<?php
$html = <<<HTML
...
HTML;
$dom = new DOMDocument();
$dom->loadHTML($html);
$script = $dom->getElementsByTagName('script');
$remove = [];
foreach($script as $item)
{
$remove[] = $item;
}
foreach ($remove as $item)
{
$item->parentNode->removeChild($item);
}
$html = $dom->saveHTML();
I have removed the HTML intentionally because even this can bork.
Use the PHP DOMDocument parser.
$doc = new DOMDocument();
// load the HTML string we want to strip
$doc->loadHTML($html);
// get all the script tags
$script_tags = $doc->getElementsByTagName('script');
$length = $script_tags->length;
// for each tag, remove it from the DOM
for ($i = 0; $i < $length; $i++) {
$script_tags->item($i)->parentNode->removeChild($script_tags->item($i));
}
// get the HTML string back
$no_script_html_string = $doc->saveHTML();
This worked me me using the following HTML document:
<!doctype html>
<html>
<head>
<meta charset="utf-8">
<title>
hey
</title>
<script>
alert("hello");
</script>
</head>
<body>
hey
</body>
</html>
Just bear in mind that the DOMDocument parser requires PHP 5 or greater.
$html = <<<HTML
...
HTML;
$dom = new DOMDocument();
$dom->loadHTML($html);
$tags_to_remove = array('script','style','iframe','link');
foreach($tags_to_remove as $tag){
$element = $dom->getElementsByTagName($tag);
foreach($element as $item){
$item->parentNode->removeChild($item);
}
}
$html = $dom->saveHTML();
A simple way by manipulating string.
function stripStr($str, $ini, $fin)
{
while (($pos = mb_stripos($str, $ini)) !== false) {
$aux = mb_substr($str, $pos + mb_strlen($ini));
$str = mb_substr($str, 0, $pos);
if (($pos2 = mb_stripos($aux, $fin)) !== false) {
$str .= mb_substr($aux, $pos2 + mb_strlen($fin));
}
}
return $str;
}
Shorter:
$html = preg_replace("/<script.*?\/script>/s", "", $html);
When doing regex things might go wrong, so it's safer to do like this:
$html = preg_replace("/<script.*?\/script>/s", "", $html) ? : $html;
So that when the "accident" happen, we get the original $html instead of empty string.
this is a merge of both ClandestineCoder & Binh WPO.
the problem with the script tag arrows is that they can have more than one variant
ex. (< = < = <) & ( > = > = >)
so instead of creating a pattern array with like a bazillion variant,
imho a better solution would be
return preg_replace('/script.*?\/script/ius', '', $text)
? preg_replace('/script.*?\/script/ius', '', $text)
: $text;
this will remove anything that look like script.../script regardless of the arrow code/variant and u can test it in here https://regex101.com/r/lK6vS8/1
Try this complete and flexible solution. It works perfectly, and is based in-part by some previous answers, but contains additional validation checks, and gets rid of additional implied HTML from the loadHTML(...) function. It is divided into two separate functions (one with a previous dependency so don't re-order/rearrange) so you can use it with multiple HTML tags that you would like to remove simultaneously (i.e. not just 'script' tags). For example removeAllInstancesOfTag(...) function accepts an array of tag names, or optionally just one as a string. So, without further ado here is the code:
/* Remove all instances of a particular HTML tag (e.g. <script>...</script>) from a variable containing raw HTML data. [BEGIN] */
/* Usage Example: $scriptless_html = removeAllInstancesOfTag($html, 'script'); */
if (!function_exists('removeAllInstancesOfTag'))
{
function removeAllInstancesOfTag($html, $tag_nm)
{
if (!empty($html))
{
$html = mb_convert_encoding($html, 'HTML-ENTITIES', 'UTF-8'); /* For UTF-8 Compatibility. */
$doc = new DOMDocument();
$doc->loadHTML($html,LIBXML_HTML_NOIMPLIED|LIBXML_HTML_NODEFDTD|LIBXML_NOWARNING);
if (!empty($tag_nm))
{
if (is_array($tag_nm))
{
$tag_nms = $tag_nm;
unset($tag_nm);
foreach ($tag_nms as $tag_nm)
{
$rmvbl_itms = $doc->getElementsByTagName(strval($tag_nm));
$rmvbl_itms_arr = [];
foreach ($rmvbl_itms as $itm)
{
$rmvbl_itms_arr[] = $itm;
}
foreach ($rmvbl_itms_arr as $itm)
{
$itm->parentNode->removeChild($itm);
}
}
}
else if (is_string($tag_nm))
{
$rmvbl_itms = $doc->getElementsByTagName($tag_nm);
$rmvbl_itms_arr = [];
foreach ($rmvbl_itms as $itm)
{
$rmvbl_itms_arr[] = $itm;
}
foreach ($rmvbl_itms_arr as $itm)
{
$itm->parentNode->removeChild($itm);
}
}
}
return $doc->saveHTML();
}
else
{
return '';
}
}
}
/* Remove all instances of a particular HTML tag (e.g. <script>...</script>) from a variable containing raw HTML data. [END] */
/* Remove all instances of dangerous and pesky <script> tags from a variable containing raw user-input HTML data. [BEGIN] */
/* Prerequisites: 'removeAllInstancesOfTag(...)' */
if (!function_exists('removeAllScriptTags'))
{
function removeAllScriptTags($html)
{
return removeAllInstancesOfTag($html, 'script');
}
}
/* Remove all instances of dangerous and pesky <script> tags from a variable containing raw user-input HTML data. [END] */
And here is a test usage example:
$html = 'This is a JavaScript retention test.<br><br><span id="chk_frst_scrpt">Congratulations! The first \'script\' tag was successfully removed!</span><br><br><span id="chk_secd_scrpt">Congratulations! The second \'script\' tag was successfully removed!</span><script>document.getElementById("chk_frst_scrpt").innerHTML = "Oops! The first \'script\' tag was NOT removed!";</script><script>document.getElementById("chk_secd_scrpt").innerHTML = "Oops! The second \'script\' tag was NOT removed!";</script>';
echo removeAllScriptTags($html);
I hope my answer really helps someone. Enjoy!
An example modifing ctf0's answer. This should only do the preg_replace once but also check for errors and block char code for forward slash.
$str = '<script> var a - 1; </script>';
$pattern = '/(script.*?(?:\/|/|/)script)/ius';
$replace = preg_replace($pattern, '', $str);
return ($replace !== null)? $replace : $str;
If you are using php 7 you can use the null coalesce operator to simplify it even more.
$pattern = '/(script.*?(?:\/|/|/)script)/ius';
return (preg_replace($pattern, '', $str) ?? $str);
function remove_script_tags($html){
$dom = new DOMDocument();
$dom->loadHTML($html);
$script = $dom->getElementsByTagName('script');
$remove = [];
foreach($script as $item){
$remove[] = $item;
}
foreach ($remove as $item){
$item->parentNode->removeChild($item);
}
$html = $dom->saveHTML();
$html = preg_replace('/<!DOCTYPE.*?<html>.*?<body><p>/ims', '', $html);
$html = str_replace('</p></body></html>', '', $html);
return $html;
}
Dejan's answer was good, but saveHTML() adds unnecessary doctype and body tags, this should get rid of it. See https://3v4l.org/82FNP
I would use BeautifulSoup if it's available. Makes this sort of thing very easy.
Don't try to do it with regexps. That way lies madness.
I had been struggling with this question. I discovered you only really need one function. explode('>', $html); The single common denominator to any tag is < and >. Then after that it's usually quotation marks ( " ). You can extract information so easily once you find the common denominator. This is what I came up with:
$html = file_get_contents('http://some_page.html');
$h = explode('>', $html);
foreach($h as $k => $v){
$v = trim($v);//clean it up a bit
if(preg_match('/^(<script[.*]*)/ius', $v)){//my regex here might be questionable
$counter = $k;//match opening tag and start counter for backtrace
}elseif(preg_match('/([.*]*<\/script$)/ius', $v)){//but it gets the job done
$script_length = $k - $counter;
$counter = 0;
for($i = $script_length; $i >= 0; $i--){
$h[$k-$i] = '';//backtrace and clear everything in between
}
}
}
for($i = 0; $i <= count($h); $i++){
if($h[$i] != ''){
$ht[$i] = $h[$i];//clean out the blanks so when we implode it works right.
}
}
$html = implode('>', $ht);//all scripts stripped.
echo $html;
I see this really only working for script tags because you will never have nested script tags. Of course, you can easily add more code that does the same check and gather nested tags.
I call it accordion coding. implode();explode(); are the easiest ways to get your logic flowing if you have a common denominator.
This is a simplified variant of Dejan Marjanovic's answer:
function removeTags($html, $tag) {
$dom = new DOMDocument();
$dom->loadHTML($html);
foreach (iterator_to_array($dom->getElementsByTagName($tag)) as $item) {
$item->parentNode->removeChild($item);
}
return $dom->saveHTML();
}
Can be used to remove any kind of tag, including <script>:
$scriptlessHtml = removeTags($html, 'script');
use the str_replace function to replace them with empty space or something
$query = '<script>console.log("I should be banned")</script>';
$badChar = array('<script>','</script>');
$query = str_replace($badChar, '', $query);
echo $query;
//this echoes console.log("I should be banned")
?>
probably a simple question to answer for someone:::
xml:
<foobar>
<foo>i am a foo</foo>
<bar>i am a bar</bar>
<foo>i am a <bar>bar</bar></foo>
</foobar>
In the above, I want to display all elements that are <foo>. When the script gets to the line with the nested < bar > the result is "i am a bar" .. which isn't the result I had hoped for.
Is it not possible to print out the entire contents of that element as it is, so that i see: "i am a <bar>bar</bar>"
php:
$xml = file_get_contents('sample');
$dom = new DOMDocument;
#$dom->loadHTML($xml);
$resources= $dom->getElementsByTagName('foo');
foreach ($resources as $resource){
echo $resource->nodeValue . "\n";
}
After some trolling and trying to do what I needed with SimpleXML, I arrived at the following conclusion. My issue with SimpleXML was where the elements are. If the xml is structured, and the hierarchy is standard ... I have no problem.
If the XML is a web page for example, and the <foo> element is anywhere, SimpleXML doesn't have a good facility like getElementsByTagName to pull out the element wherever it may be....
<?php
$doc = new DOMDocument();
$doc->load('sample');
$element_name = 'foo';
if ($doc->getElementsByTagName($element_name)->length > 0) {
$resources = $doc->getElementsByTagName($element_name);
foreach ($resources as $resource) {
$id = null;
if (!$resource->hasAttribute('id')) {
$resource->setAttribute('id', gen_uuid());
}
$innerHTML = null;
$children = $resource->childNodes;
foreach ($children as $child) {
$tmp_doc = new DOMDocument();
$tmp_doc->appendChild($tmp_doc->importNode($child,true));
$innerHTML .= rtrim($tmp_doc->saveHTML());
}
$resource->nodevalue = $innerHTML;
}
}
echo $doc->saveHTML();
?>
Rather than writing all that code, you might try XPath. That expression would be "//foo", which would get a list of all the elements in the document named "foo".
http://php.net/manual/en/simplexmlelement.xpath.php
I'm working on a small templating engine, and I'm using DOMDocument to parse the pages. My test page so far looks like this:
<block name="content">
<?php echo 'this is some rendered PHP! <br />' ?>
<p>Main column of <span>content</span></p>
</block>
And part of my class looks like this:
private function parse($tag, $attr = 'name')
{
$strict = 0;
/*** the array to return ***/
$out = array();
if($this->totalBlocks() > 0)
{
/*** a new dom object ***/
$dom = new domDocument;
/*** discard white space ***/
$dom->preserveWhiteSpace = false;
/*** load the html into the object ***/
if($strict==1)
{
$dom->loadXML($this->file_contents);
}
else
{
$dom->loadHTML($this->file_contents);
}
/*** the tag by its tag name ***/
$content = $dom->getElementsByTagname($tag);
$i = 0;
foreach ($content as $item)
{
/*** add node value to the out array ***/
$out[$i]['name'] = $item->getAttribute($attr);
$out[$i]['value'] = $item->nodeValue;
$i++;
}
}
return $out;
}
I have it working the way I want in that it grabs each <block> on the page and injects it's contents into my template, however, it is stripping the HTML tags within the <block>, thus returning the following without the <p> or <span> tags:
this is some rendered PHP! Main column of content
What am I doing wrong here? :) Thanks
Nothing: nodeValue is the concatenation of the value portion of the tree, and will never have tags.
What I would do to make an HTML fragment of the tree under $node is this:
$doc = new DOMDocument();
foreach($node->childNodes as $child) {
$doc->appendChild($doc->importNode($child, true));
}
return $doc->saveHTML();
HTML "fragments" are actually more problematic than you'd think at first, because they tend to lack things like doctypes and character sets, which makes it hard to deterministically go back and forth between portions of a DOM tree and HTML fragments.