Question: How do I insert a new inline style?

[Steve McKinley]

I am trying to find every instance of line-height, and add the additional mso line-height style. My code works as expected, except for the final step where the insert is supposed to happen. After the code runs, $text remains unchanged.

 $tagArray = ['h1', 'h2', 'h3', 'h4', 'h5', 'h6', 'p', 'span'];
 $pattern = '/(line-height:\s\d+\.?\d+\%?\;)/';
 $dom = HtmlDomParser::str_get_html($text); // $text comes from Summernote
 // iterate through tags h1, h2, etc.
 foreach ($tagArray as $t) {
     $tags = $dom->findMulti($t);
     // Iterate through all tags of type $t
     foreach ($tags as $i => $tag) {
         // Check if style with line-height attribute exists
         if (!empty($tag->style)
             && str_contains($tag->style, 'line-height') 
             && !str_contains($tag->style, 'mso')) {
             // Isolate line-height and insert mso style before line-height
             preg_match($pattern, $tag->style, $match);
             $replace = $this->style('MSOLineHeight') . $this->space . $match[0];
             $tag->style = preg_replace($pattern, $replace, $tag->style); <!-----  This doesn't work ----->
         }
    }
}

$tag->style before replace:
string(34) "font-size: 22px; line-height: 1.6;"

$replace:
string(108) "mso-line-height-rule: exactly; -ms-text-size-adjust: 100%; -webkit-text-size-adjust: 100%; line-height: 1.6;"

$tag->style after replace:
string(125) "font-size: 22px; mso-line-height-rule: exactly; -ms-text-size-adjust: 100%; -webkit-text-size-adjust: 100%; line-height: 1.6;"

But $text remains unchanged.

[Steve McKinley]

Nevermind! I found critical step: $dom->save();