WordPress WYSIWYG delete "line" attribute

Hi,

You can try adding this to the top of wp-content/plugins/wp-syntax/wp-syntax.php (although ideally you might want to make this a separate plugin so the changes don’t get deleted next time wp-syntax gets updated):

// Allow 'line', 'escaped' and 'highlight' attributes on <pre> in TinyMCE
function tinymce_add_preAttr( $arr = array() ) {
  $extra = 'pre[lang|line|escaped|style|width|highlight]';

  if ( isset( $arr['extended_valid_elements'] ) ) {
    // append to existing value
    $arr['extended_valid_elements'] .= ',' . $extra;
  } else {
    // set the value
    $arr['extended_valid_elements'] = $extra;
  }

  return $arr;
}

add_filter('tiny_mce_before_init','tinymce_add_preAttr');

Next time you load the WYSIWYG-editor, it should accept the necessary attributes on the “pre” tag.

( Credits: adapted from https://wordpress.stackexchange.com/questions/14363/switching-from-html-to-visual-editor-and-back-completely-strips-page-contents/14408#14408 )

Nice. I was going to say maybe wp-syntax could be modified to parse the class attribute for settings, but this is much better!

Question: does this replace the list of valid attributes, or just hint as to what is allowed beyond the norm. I only ask because I noticed you didn’t have “class” in the list.

Hi,
I never noticed before this but yes, according to this (and my own testing seems to confirm it is true) it does _replace_ the list of valid attributes.

You will need to add the attributes you want allowed on “pre” in the code above (ex. for “class”: $extra = ‘pre[class|lang|line|escaped|style|width|highlight]’;) or just use “*” if you want to allow all attributes (ex: $extra = ‘pre[*]’;)

For reference, by default “pre” gets its list of valid attributes from the “default rule set” defined here

Edit: more specifically, the default attributes for “pre” seem to come from the “@” rule which states: “[id|class|style|title|dir<ltr?rtl|lang|xml::lang|onclick|ondblclick|”
+ “onmousedown|onmouseup|onmouseover|onmousemove|onmouseout|onkeypress|”
+ “onkeydown|onkeyup]”