Modify html attribute with php - php

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)

Related

Extract Button Text Using PHP [duplicate]

This question already has answers here:
How to get innerHTML of DOMNode?
(9 answers)
Closed 5 years ago.
How to Change innerHTML of a php DOMElement ?
Another solution:
1) create new DOMDocumentFragment from the HTML string to be inserted;
2) remove old content of our element by deleting its child nodes;
3) append DOMDocumentFragment to our element.
function setInnerHTML($element, $html)
{
$fragment = $element->ownerDocument->createDocumentFragment();
$fragment->appendXML($html);
while ($element->hasChildNodes())
$element->removeChild($element->firstChild);
$element->appendChild($fragment);
}
Alternatively, we can replace our element with its clean copy and then append DOMDocumentFragment to this clone.
function setInnerHTML($element, $html)
{
$fragment = $element->ownerDocument->createDocumentFragment();
$fragment->appendXML($html);
$clone = $element->cloneNode(); // Get element copy without children
$clone->appendChild($fragment);
$element->parentNode->replaceChild($clone, $element);
}
Test:
$doc = new DOMDocument();
$doc->loadXML('<div><span style="color: green">Old HTML</span></div>');
$div = $doc->getElementsByTagName('div')->item(0);
echo $doc->saveHTML();
setInnerHTML($div, '<p style="color: red">New HTML</p>');
echo $doc->saveHTML();
// Output:
// <div><span style="color: green">Old HTML</span></div>
// <div><p style="color: red">New HTML</p></div>
I needed to do this for a project recently and ended up with an extension to DOMElement: http://www.keyvan.net/2010/07/javascript-like-innerhtml-access-in-php/
Here's an example showing how it's used:
<?php
require_once 'JSLikeHTMLElement.php';
$doc = new DOMDocument();
$doc->registerNodeClass('DOMElement', 'JSLikeHTMLElement');
$doc->loadHTML('<div><p>Para 1</p><p>Para 2</p></div>');
$elem = $doc->getElementsByTagName('div')->item(0);
// print innerHTML
echo $elem->innerHTML; // prints '<p>Para 1</p><p>Para 2</p>'
// set innerHTML
$elem->innerHTML = 'FF';
// print document (with our changes)
echo $doc->saveXML();
?>
I think the best thing you can do is come up with a function that will take the DOMElement that you want to change the InnerHTML of, copy it, and replace it.
In very rough PHP:
function replaceElement($el, $newInnerHTML) {
$newElement = $myDomDocument->createElement($el->nodeName, $newInnerHTML);
$el->parentNode->insertBefore($newElement, $el);
$el->parentNode->removeChild($el);
return $newElement;
}
This doesn't take into account attributes and nested structures, but I think this will get you on your way.
I ended up making this function using a few functions from other people on this page. I changed the one from Joanna Goch the way that Peter Brand says mostly, and also added some code from Guest and from other places.
This function does not use an extension, and does not use appendXML (which is very picky and breaks even if it sees one BR tag that is not closed) and seems to be working good.
function set_inner_html( $element, $content ) {
$DOM_inner_HTML = new DOMDocument();
$internal_errors = libxml_use_internal_errors( true );
$DOM_inner_HTML->loadHTML( mb_convert_encoding( $content, 'HTML-ENTITIES', 'UTF-8' ) );
libxml_use_internal_errors( $internal_errors );
$content_node = $DOM_inner_HTML->getElementsByTagName('body')->item(0);
$content_node = $element->ownerDocument->importNode( $content_node, true );
while ( $element->hasChildNodes() ) {
$element->removeChild( $element->firstChild );
}
$element->appendChild( $content_node );
}
It seems that appendXML doesn't work always - for example if you try to append XML with 3 levels. Here is the function I wrote that always work (you want to set $content as innerHTML to $element):
function setInnerHTML($DOM, $element, $content) {
$DOMInnerHTML = new DOMDocument();
$DOMInnerHTML->loadHTML($content);
$contentNode = $DOMInnerHTML->getElementsByTagName('body')->item(0)->firstChild;
$contentNode = $DOM->importNode($contentNode, true);
$element->appendChild($contentNode);
return $elementNode;
}
Have a look at this library PHP Simple HTML DOM Parser http://simplehtmldom.sourceforge.net/
It looks pretty straightforward. You can change innertextproperty of your elements. It might help.
Here is a replace by class function I just wrote:
It will replace the innerHtml of a class. You can also specify the node type eg. div/p/a etc.
function replaceInnerHtmlByClass($html, $replace=null, $class=null, $nodeType=null){
if(!$nodeType){ $nodeType = '*'; }
$dom = new DOMDocument();
$dom->loadHTML($html);
$xpath = new DOMXPath($dom);
$nodes = $xpath->query("//{$nodeType}[contains(concat(' ', normalize-space(#class), ' '), '$class')]");
foreach($nodes as $node) {
while($node->childNodes->length){
$node->removeChild($node->firstChild);
}
$fragment = $dom->createDocumentFragment();
$fragment->appendXML($replace);
$node->appendChild($fragment);
}
return $dom->saveHTML($dom->documentElement);
}
Here is another function I wrote to remove nodes with a specific class but preserving the inner html.
Setting replace to true will discard the inner html.
Setting replace to any other content will replace the inner html with the provided content.
function stripTagsByClass($html, $class=null, $nodeType=null, $replace=false){
if(!$nodeType){ $nodeType = '*'; }
$dom = new DOMDocument();
$dom->loadHTML($html);
$xpath = new DOMXPath($dom);
$nodes = $xpath->query("//{$nodeType}[contains(concat(' ', normalize-space(#class), ' '), '$class')]");
foreach($nodes as $node) {
$innerHTML = '';
$children = $node->childNodes;
foreach($children as $child) {
$tmp = new DOMDocument();
$tmp->appendChild($tmp->importNode($child,true));
$innerHTML .= $tmp->saveHTML();
}
$fragment = $dom->createDocumentFragment();
if($replace !== null && $replace !== false){
if($replace === true){ $replace = ''; }
$innerHTML = $replace;
}
$fragment->appendXML($innerHTML);
$node->parentNode->replaceChild($fragment, $node);
}
return $dom->saveHTML($dom->documentElement);
}
Theses functions can easily be adapted to use other attributes as the selector.
I only needed it to evaluate the class attribute.
Developing on from Joanna Goch's answer, this function will insert either a text node or an HTML fragment:
function nodeFromContent($node, $content) {
//creates a text node, or dom node if content contains html
$lt = strpos($content, '<');
$gt = strrpos($content, '>');
if (!($lt === false || $gt === false) && $gt > $lt) {
//< followed by > means potentially contains HTML
$DOMInnerHTML = new DOMDocument();
$DOMInnerHTML->loadHTML($content);
$contentNode = $DOMInnerHTML->getElementsByTagName('body')->item(0);
$newNode = $node->ownerDocument->importNode($contentNode, true);
} else {
$newNode = $node->ownerDocument->createTextNode($content);
}
return $newNode;
}
usage
$newNode = nodeFromContent($node, $content);
$node->parentNode->insertBefore($newNode, $node);
//or $node->appendChild($newNode) depending on what you require
here is how you do it:
$doc = new DOMDocument('');
$label = $doc->createElement('label');
$label->appendChild($doc->createTextNode('test'));
$li->appendChild($label);
echo $doc->saveHTML();
function setInnerHTML($DOM, $element, $innerHTML) {
$node = $DOM->createTextNode($innerHTML);
$element->appendChild($node);
}

Removing every li tag before reaching the first p tag in string

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();

How can i identify the relation=NoFOLLOW links

I would like to know how can we identify the Nofollow relation in the URL through PHP REGEX.
<a href="abc.html" rel="NOFOLLOW">How to check NOFOLLOW<a>
Please give me the solution to findout this things
You could try with something such as...
preg_match('/<a.+?rel="nofollow".*?>[\s\S]*?<\/a>/i', $html);
CodePad.
But you are better off using a HTML parser which deals with things that a regex can not.
$dom = new DOMDocument;
$dom->loadHTML($html);
$anchors = $dom->getElementsByTagName('a');
foreach($anchors as $anchor) {
if ($anchor->hasAttribute('rel')) {
$rel = preg_split('/\s+/', strtolower($anchor->getAttribute('rel')));
if (in_array('nofollow', $rel)) {
echo 'This anchor is "nofollow"\'d.';
}
}
}
CodePad.

How should I get a div's content like this using dom in php?

The div is like this
<div style="width:90%;margin:0 auto;color:#Black;" id="content">
this is text, severaltags
</div>
how should i get the div's content including the tags using dom in php?
Assuming your using PHP5 you can use DOMDocument -- take note that this doesn't provide simple means for retrieving inner html of an element. You can do something along the following:
function DOMinnerHTML($element)
{
$innerHTML = "";
$children = $element->childNodes;
foreach ($children as $child)
{
$tmp_dom = new DOMDocument();
$tmp_dom->appendChild($tmp_dom->importNode($child, true));
$innerHTML.=trim($tmp_dom->saveHTML());
}
return $innerHTML;
}
$dom = new DOMDocument();
$dom->loadHTML($html);
$items = $dom->getElementsByTagName('div');
if ($items->length)
{
$innerHTML = DOMinnerHTML($items->item(0));
}
echo $innerHTML;
For something this simple, although I don't normally recommend it, I'd use regex:
preg_match('|<div[^>]+>(.*?)</div>|is', $html, $match);
if ($match)
{
echo 'html is: ' . $match[1][0];
}
Something like this?
$document = new DOMDocument();
$document->loadHTML($html);
$element = $document->getElementById('content');
To get the values, you can try something like this
$doc = new DOMDocument();
$doc->loadHTMLFile('link-t0-html-file.php');
$xpath = new DOMXPath($doc);
$element = $xpath->query("//*[#id='content']")->item(0);
echo $element->nodeValue;
if i am not wrong you want this
echo "< div style='width:90%;margin:0 auto;color:#000000;font-size:14px;line-height:24px;'
id='content'>";
echo "this is text, several `<br/>` tags";
echo "< /div>";
just mind it never use double quote (") within double quote ("). use single quote(') within double quote.

Change innerHTML of a php DOMElement [duplicate]

This question already has answers here:
How to get innerHTML of DOMNode?
(9 answers)
Closed 5 years ago.
How to Change innerHTML of a php DOMElement ?
Another solution:
1) create new DOMDocumentFragment from the HTML string to be inserted;
2) remove old content of our element by deleting its child nodes;
3) append DOMDocumentFragment to our element.
function setInnerHTML($element, $html)
{
$fragment = $element->ownerDocument->createDocumentFragment();
$fragment->appendXML($html);
while ($element->hasChildNodes())
$element->removeChild($element->firstChild);
$element->appendChild($fragment);
}
Alternatively, we can replace our element with its clean copy and then append DOMDocumentFragment to this clone.
function setInnerHTML($element, $html)
{
$fragment = $element->ownerDocument->createDocumentFragment();
$fragment->appendXML($html);
$clone = $element->cloneNode(); // Get element copy without children
$clone->appendChild($fragment);
$element->parentNode->replaceChild($clone, $element);
}
Test:
$doc = new DOMDocument();
$doc->loadXML('<div><span style="color: green">Old HTML</span></div>');
$div = $doc->getElementsByTagName('div')->item(0);
echo $doc->saveHTML();
setInnerHTML($div, '<p style="color: red">New HTML</p>');
echo $doc->saveHTML();
// Output:
// <div><span style="color: green">Old HTML</span></div>
// <div><p style="color: red">New HTML</p></div>
I needed to do this for a project recently and ended up with an extension to DOMElement: http://www.keyvan.net/2010/07/javascript-like-innerhtml-access-in-php/
Here's an example showing how it's used:
<?php
require_once 'JSLikeHTMLElement.php';
$doc = new DOMDocument();
$doc->registerNodeClass('DOMElement', 'JSLikeHTMLElement');
$doc->loadHTML('<div><p>Para 1</p><p>Para 2</p></div>');
$elem = $doc->getElementsByTagName('div')->item(0);
// print innerHTML
echo $elem->innerHTML; // prints '<p>Para 1</p><p>Para 2</p>'
// set innerHTML
$elem->innerHTML = 'FF';
// print document (with our changes)
echo $doc->saveXML();
?>
I think the best thing you can do is come up with a function that will take the DOMElement that you want to change the InnerHTML of, copy it, and replace it.
In very rough PHP:
function replaceElement($el, $newInnerHTML) {
$newElement = $myDomDocument->createElement($el->nodeName, $newInnerHTML);
$el->parentNode->insertBefore($newElement, $el);
$el->parentNode->removeChild($el);
return $newElement;
}
This doesn't take into account attributes and nested structures, but I think this will get you on your way.
I ended up making this function using a few functions from other people on this page. I changed the one from Joanna Goch the way that Peter Brand says mostly, and also added some code from Guest and from other places.
This function does not use an extension, and does not use appendXML (which is very picky and breaks even if it sees one BR tag that is not closed) and seems to be working good.
function set_inner_html( $element, $content ) {
$DOM_inner_HTML = new DOMDocument();
$internal_errors = libxml_use_internal_errors( true );
$DOM_inner_HTML->loadHTML( mb_convert_encoding( $content, 'HTML-ENTITIES', 'UTF-8' ) );
libxml_use_internal_errors( $internal_errors );
$content_node = $DOM_inner_HTML->getElementsByTagName('body')->item(0);
$content_node = $element->ownerDocument->importNode( $content_node, true );
while ( $element->hasChildNodes() ) {
$element->removeChild( $element->firstChild );
}
$element->appendChild( $content_node );
}
It seems that appendXML doesn't work always - for example if you try to append XML with 3 levels. Here is the function I wrote that always work (you want to set $content as innerHTML to $element):
function setInnerHTML($DOM, $element, $content) {
$DOMInnerHTML = new DOMDocument();
$DOMInnerHTML->loadHTML($content);
$contentNode = $DOMInnerHTML->getElementsByTagName('body')->item(0)->firstChild;
$contentNode = $DOM->importNode($contentNode, true);
$element->appendChild($contentNode);
return $elementNode;
}
Have a look at this library PHP Simple HTML DOM Parser http://simplehtmldom.sourceforge.net/
It looks pretty straightforward. You can change innertextproperty of your elements. It might help.
Here is a replace by class function I just wrote:
It will replace the innerHtml of a class. You can also specify the node type eg. div/p/a etc.
function replaceInnerHtmlByClass($html, $replace=null, $class=null, $nodeType=null){
if(!$nodeType){ $nodeType = '*'; }
$dom = new DOMDocument();
$dom->loadHTML($html);
$xpath = new DOMXPath($dom);
$nodes = $xpath->query("//{$nodeType}[contains(concat(' ', normalize-space(#class), ' '), '$class')]");
foreach($nodes as $node) {
while($node->childNodes->length){
$node->removeChild($node->firstChild);
}
$fragment = $dom->createDocumentFragment();
$fragment->appendXML($replace);
$node->appendChild($fragment);
}
return $dom->saveHTML($dom->documentElement);
}
Here is another function I wrote to remove nodes with a specific class but preserving the inner html.
Setting replace to true will discard the inner html.
Setting replace to any other content will replace the inner html with the provided content.
function stripTagsByClass($html, $class=null, $nodeType=null, $replace=false){
if(!$nodeType){ $nodeType = '*'; }
$dom = new DOMDocument();
$dom->loadHTML($html);
$xpath = new DOMXPath($dom);
$nodes = $xpath->query("//{$nodeType}[contains(concat(' ', normalize-space(#class), ' '), '$class')]");
foreach($nodes as $node) {
$innerHTML = '';
$children = $node->childNodes;
foreach($children as $child) {
$tmp = new DOMDocument();
$tmp->appendChild($tmp->importNode($child,true));
$innerHTML .= $tmp->saveHTML();
}
$fragment = $dom->createDocumentFragment();
if($replace !== null && $replace !== false){
if($replace === true){ $replace = ''; }
$innerHTML = $replace;
}
$fragment->appendXML($innerHTML);
$node->parentNode->replaceChild($fragment, $node);
}
return $dom->saveHTML($dom->documentElement);
}
Theses functions can easily be adapted to use other attributes as the selector.
I only needed it to evaluate the class attribute.
Developing on from Joanna Goch's answer, this function will insert either a text node or an HTML fragment:
function nodeFromContent($node, $content) {
//creates a text node, or dom node if content contains html
$lt = strpos($content, '<');
$gt = strrpos($content, '>');
if (!($lt === false || $gt === false) && $gt > $lt) {
//< followed by > means potentially contains HTML
$DOMInnerHTML = new DOMDocument();
$DOMInnerHTML->loadHTML($content);
$contentNode = $DOMInnerHTML->getElementsByTagName('body')->item(0);
$newNode = $node->ownerDocument->importNode($contentNode, true);
} else {
$newNode = $node->ownerDocument->createTextNode($content);
}
return $newNode;
}
usage
$newNode = nodeFromContent($node, $content);
$node->parentNode->insertBefore($newNode, $node);
//or $node->appendChild($newNode) depending on what you require
here is how you do it:
$doc = new DOMDocument('');
$label = $doc->createElement('label');
$label->appendChild($doc->createTextNode('test'));
$li->appendChild($label);
echo $doc->saveHTML();
function setInnerHTML($DOM, $element, $innerHTML) {
$node = $DOM->createTextNode($innerHTML);
$element->appendChild($node);
}

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