Document: add MathJax script in all HTML document before returning the document for download - refs BT#21424

Author: NicoDucou

main/inc/lib/document.lib.php

@@ -427,6 +427,7 @@ public static function file_send_for_download(
 
  switch ($contentType) {
  case 'text/html':
+ $enableMathJaxScript = api_get_setting('enabled_mathjax');
  if (isset($lpFixedEncoding) && $lpFixedEncoding === 'true') {
  $contentType .= '; charset=UTF-8';
  } else {
@@ -480,15 +481,23 @@ public static function file_send_for_download(
  ['https%3A%2F%2F', 'https://'],
  $content
  );
+ if ($enableMathJaxScript) {
+ $content = self::includeMathJaxScript($content);
+ }
  echo $content;
  } else {
- if (function_exists('ob_end_clean') && ob_get_length()) {
- // Use ob_end_clean() to avoid weird buffering situations
- // where file is sent broken/incomplete for download
- ob_end_clean();
+ if ($enableMathJaxScript) {
+ $content = file_get_contents($full_file_name);
+ $content = self::includeMathJaxScript($content);
+ echo $content;
+ } else {
+ if (function_exists('ob_end_clean') && ob_get_length()) {
+ // Use ob_end_clean() to avoid weird buffering situations
+ // where file is sent broken/incomplete for download
+ ob_end_clean();
+ }
+ readfile($full_file_name);
  }
-
- readfile($full_file_name);
  }
 
  return true;
@@ -7516,4 +7525,26 @@ private static function getButtonDelete(
 
  return $btn;
  }
+
+ /**
+ * Include MathJax script in document.
+ *
+ * @param string file content $content
+ *
+ * @return string file content
+ */
+ private static function includeMathJaxScript($content)
+ {
+ $scriptTag = '<script src="'.api_get_path(WEB_PUBLIC_PATH).'assets/MathJax/MathJax.js?config=TeX-MML-AM_HTMLorMML"></script>';
+ // Find position of </body> tag
+ $pos = strpos($content, '</body>');
+ // If </body> tag found, insert the script tag before it
+ if ($pos !== false) {
+ $content = substr_replace($content, $scriptTag, $pos, 0);
+ } else {
+ // If </body> tag not found, just append the script tag at the end
+ $content .= $scriptTag;
+ }
+ return $content;
+ }
 }