Add option to preserve conditional comments

changelog.md

@@ -1,5 +1,8 @@
 # Changelog
 
+## 2.2
+- Added option to preserve conditional comments `<!--[if lt IE 10]>IE only<![endif]-->`.
+
 ## 2.1
 
 - Added experimental feature support for minify `<script type="json-ld"></script>`.

composer.json

@@ -1,7 +1,7 @@
 {
     "name": "jenstornell/tiny-html-minifier",
     "description": "Minify HTML in PHP with just a single class",
-    "version": "2.1",
+    "version": "2.2",
     "type": "library",
     "license": "MIT",
     "authors": [

readme.md

@@ -1,6 +1,6 @@
 # Tiny Html Minifier
 
-![Version 2.0](https://img.shields.io/badge/version-2.0-blue.svg) ![MIT license](https://img.shields.io/badge/license-MIT-green.svg) [![Donate](https://img.shields.io/badge/give-donation-yellow.svg)](https://www.paypal.me/DevoneraAB)
+![Version 2.2](https://img.shields.io/badge/version-2.2-blue.svg) ![MIT license](https://img.shields.io/badge/license-MIT-green.svg) [![Donate](https://img.shields.io/badge/give-donation-yellow.svg)](https://www.paypal.me/DevoneraAB)
 
 [Changelog](changelog.md)
 
@@ -106,6 +106,7 @@ require 'tiny-html-minifier.php';
 echo TinyMinify::html($html, $options = [
     'collapse_whitespace' => false,
     'collapse_json_lt' => false, // WARNING - EXPERIMENTAL FEATURE
+    'preserve_conditional_comments' => false,
 ]);
 ```
 
@@ -127,6 +128,21 @@ Spaces are collapsed. The text inside the element is still untouched. Set this v
 <ul><li><a href="#">My link</a></li><li><a href="#">My link</a></li></ul>
 ```
 
+### preserve_conditional_comments
+
+#### Do not preserve
+
+All comments will be removed `<!-- Whatever -->`, also conditional comments `<!--[if lt IE 10]>...<![endif]-->`).
+
+
+#### Preserve
+
+Conditional comments will be preserved. Other comments `<!-- Whatever -->` will be removed.
+
+```html
+<!--[if lt IE 10]>IE only<![endif]-->
+```
+
 ### collapse_json_lt
 
 ***This is an experimental feature that could break your site!***

tiny-html-minifier.php

@@ -52,11 +52,11 @@ function __construct($options) {
     // Run minifier
     function minify($html) {
         $html = $this->removeComments($html);
-        
+
         $rest = $html;
 
         while(!empty($rest)) :
-         
+
             $parts = explode('<', $rest, 2);
 
             $this->walk($parts[0]);
@@ -73,7 +73,7 @@ function walk(&$part) {
 
         $tag_parts = explode('>', $part);
         $tag_content = $tag_parts[0];
-        
+
         if(!empty($tag_content)) {
             $name = $this->findName($tag_content);
             $element = $this->toElement($tag_content, $part, $name);
@@ -107,7 +107,8 @@ function walk(&$part) {
 
     // Remove comments
     function removeComments($content = '') {
-        return preg_replace('/<!--(.|\s)*?-->/', '', $content);
+        $regexp = empty($this->options['preserve_conditional_comments']) ? '/<!--(.|\s)*?-->/' : '/<!--((?![\[]{1,1}).|\s)*?-->/';
+        return preg_replace($regexp, '', $content);
     }
 
     // Check if string contains string
@@ -209,13 +210,13 @@ function buildHtml() {
         foreach($this->build as $build) {
 
             if(!empty($this->options['collapse_whitespace'])) {
-                
+
                 if(strlen(trim($build['content'])) == 0)
                     continue;
-                
+
                 elseif($build['type'] != 'content' && !in_array($build['name'], $this->elements['inline']))
                     trim($build['content']);
-                
+
             }
 
             $this->output .= $build['content'];