Question

need change the value of a tag html, in a file html.
I tried to use function preg_replace() but I am not able to change anything.

the html file:

 ...
 <div id="phrase_of_day">
     <div>
         <span class="icon quote"></span>
         <h1>Frase do Dia</h1>
         <blockquote><p>value to change</p></blockquote>
     </div>
 </div>
 ...

I try this:

$url = '../index.html';

$file = file_get_contents($url);

$o = preg_replace('/.*<div id="phrase_of_day">.*<blockquote><p>(\w+)<\/p><\/blockquote>/','hello world', $file);

file_put_contents('test.html', $o);

Anyone know where I was wrong?

UPDATE

I try with DOMDocument class, like Madara Uchiha as suggested, but now I have a problem of encoding special characters.

example:

origin: <h1>Gerar Parágrafos</h1>
after: <h1>Gerar Par&Atilde;&iexcl;grafos</h1>

code:

libxml_use_internal_errors(true);
$document = new DOMDocument('1.0', 'UTF-8');
$document->loadHTMLFile($url);
$document->encoding = 'UTF-8';

$blockquote = $document
    ->getElementById("phrase_of_day") //Div
    ->getElementsByTagName("blockquote")->item(0);

$new_value = new DOMElement("p", "New Value for Element");
$blockquote->replaceChild($new_value, $blockquote->childNodes->item(0));

$document->saveHTMLFile('test.html');
libxml_use_internal_errors(false);

Answer 1

You should not use regex to parse HTML.

But, if you really want to, then you should use this regex >>

$o = preg_replace(
  '/(<div id="phrase_of_day">.*?<blockquote><p>)([^<]+)(<\/p><\/blockquote>)/s', 
  '$1hello world$3',
  $file);

Check this demo.