Fixes #3307: Removes empty lessons section & title from single course page.

[hansschuijff]

Fixes #3307

Changes proposed in this Pull Request

• Remove empty lessons html from single course page
• In the process moves actions 'sensei_single_course_lessons_before' and 'sensei_single_course_lessons_after' outside of the course-lessons section, so the section can be dependent on post having been found.
• In Sensei LMS the above actions seem only to be used for for setting up and resetting the query and some globals, so moving them outside the section should be possible.

Testing instructions

• Works on single course page ( /course/{course-slug}/ ) and a page using the [sensei_course_page] shortcode.

[donnapep]

On the single course page for unsupported themes like Divi (themes that don't explicitly declare support for Sensei LMS or for which we don't have a custom integration), there's an empty <header><h1> element:

On supported themes like Storefront, that element contains the course title:

Does it seem possible to remove the empty <header> tag for unsupported themes as well?

[hansschuijff]

@donnapep I'll see what I can do. It's been a while, so I have to recall first what I have done here. I'll let you know.

[hansschuijff]

@donnapep I've added a condition to the_title() so the header/h1 is only inserted when the title is not empty. Since I found the same problem was also present in the_title() for lessons, I have performed the same edit in all 4 the_title() methods (course, lesson, quiz and message). In all cases the header block is only inserted when there is content in it. It seems to work like this.