Prevent completion of content until flagged by user

@djdevin Are you suggesting that by visiting just the regular node view page that it marks it as completed? Is that the trick then? Going to node/123/course-object/789 sets a start date, after which going to node/123 would set it as completed?

I thought that going to node/123/course-object/789 set it as completed, as well as started?

I'm talking here about regular course materials, not quizzes, just to be clear.

Thanks for explaining that more clearly.

So how would you suggest I go about letting the user view the course material such that it either does nothing or at least marks it as started, but not completed, and then give them a URL they can visit to mark it as completed when they are ready?

Going to the node/123/course-object/789 URL, as mentioned, immediately marks it as both started and completed instantly, and this is not desired.

Ah, now I see the code where it sets the fulfilment status to complete upon viewing the node.

Line 25 is course_content.module:

/**
 * Implements hook_node_view().
 */
function course_content_node_view($node, $view_mode = 'full') {
  if ($view_mode == 'full' && variable_get("course_content_use_{$node->type}", 0)) {
    global $user;
    if ($courseObject = course_get_course_object('course_content', $node->type, $node->nid, $user)) {
      $courseObject->getFulfillment()->setComplete()->save();
    }
  }
}

This is essentially what I'd like to avoid. Clearly this hook fires whether you just go to the normal node view, or the full course object URL, but the latter also sets the start time.

I'm not sure I fully appreciate why it works this way. Is my particular use case really that unique? Am I the only person who has ever wanted to be able to view a course object without immediately marking it as complete, and instead allow the user to take an action that does that instead?

Yeah what my client wants really is a way to flag that they have read the material, so what you're talking about there is one idea. Though, because it's on node view that the course object gets marked as completed, even if you used the flag module I'm not sure how you'd prevent that from happening.

I think that if I want to work with the system properly that what I should do perhaps is implement my own URL for viewing the node and marking the course object as started, which then redirects to the regular node view URL when you click the "I have read this material" link that I currently have in place, and that will trigger it to automatically mark it as completed.

So after further thought I think I see what you're suggesting with the flag module - to use that as the way to check status of completion instead of using the course module's fulfilment data. Just leave the internals alone and use your own method, basically.

Since I've already done a lot of work that relies on using the internal fulfilment data - and would need to for quizzes anyway - this didn't seem like the pragmatic solution to me. However, I do want it to be able to rely on the isComplete() method and have it work properly, so I implemented a workaround. I checked to see that my own module's hook_node_view is running after the hook in course_content, which it is, and basically had it undo what the course_content_hook_node_view does, like so:

if ($view_mode == 'full' && variable_get("course_content_use_{$node->type}", 0)) {
  global $user;
  if ($courseObject = course_get_course_object('course_content', $node->type, $node->nid, $user)) {
    // The course content module always automatically
    // sets the fulfillment status to complete when the
    // node is viewed. However, we want to undo that if
    // the course has not yet been marked as started,
    // which is what happens when you view the node directly
    // BEFORE following the full course object link. This
    // accommodates our need to be able to not have course
    // objects marked as completed until the user chooses
    // to do so. They are linked directly to the node view
    // first, and have a button to go to the full course object
    // URL when they choose. So with this code, we ensure that
    // it does not get marked as complete until you have followed
    // that particular path.
    $fulfillment = $courseObject->getFulfillment();
    if ($fulfillment->isComplete() && !$fulfillment->getOption('date_started')) {
      $fulfillment->delete();
    }
  }
}

So basically, if it's been marked as completed but not started, then I change it back to having no completion date and completion flag set to zero. Then, the user will click a link to "mark it as completed" that follows the full course object URL, which then marks the start date, redirects to the node view which triggers the hook to mark it completed, and all is well. My hook will do nothing if it's marked as complete AND has a start date.

So, it seems like a bit of a hackish workaround, but it did seem like the most pragmatic solution for now. Hopefully others who need some similar functionality can learn something helpful from this issue thread.

Ah yes that is a much more elegant solution, thank you! I had not thought about using hook_entity_presave. The following code works in D7 (hook_ENTITY_TYPE_presave(), as you've suggested, is D8 only):

function maca_courses_entity_presave($entity, $entity_type) {
  if ($entity_type == 'course_object_fulfillment' && $entity->getCourseObject()->getModule() == 'course_content') {
    if ($entity->isComplete() && !$entity->getOption('date_started')) {
      $entity->setComplete(0);
      $entity->setOption('date_completed', NULL);
    }
  }
}

This still saves fulfilment data in the database, while my other solution would just delete it, but the end result is the same and doesn't cause any problems.