Actually, I managed to solve this problem in another way. I post here the solution in case somebody else is interested in the answer:
1) I created a Wysiwyg Editor field.
2) Added the field normally in my php file.
3) In the post editor, I used the normal wordpress “more” tag, which automatically inserts the shortcode <!–more–> inside my content and creates two paragraphs automatically, one before and one after the shortcode.
4) In my Jquery file, I wrote this code:
$('p').html(function(_, text) {
return text.replace('<!--more-->', '<a href="#" class="read_more">read more</a>' );
});
That’s it, basically. With that link and that class I can manipulate the link as I want.
