BookStack\Repos\PageRepo::updatePage PHP Method

    public function updatePage(Page $page, $book_id, $input)
    {
        // Hold the old details to compare later
        $oldHtml = $page->html;
        $oldName = $page->name;
        // Prevent slug being updated if no name change
        if ($page->name !== $input['name']) {
            $page->slug = $this->findSuitableSlug($input['name'], $book_id, $page->id);
        }
        // Save page tags if present
        if (isset($input['tags'])) {
            $this->tagRepo->saveTagsToEntity($page, $input['tags']);
        }
        // Update with new details
        $userId = user()->id;
        $page->fill($input);
        $page->html = $this->formatHtml($input['html']);
        $page->text = strip_tags($page->html);
        if (setting('app-editor') !== 'markdown') {
            $page->markdown = '';
        }
        $page->updated_by = $userId;
        $page->save();
        // Remove all update drafts for this user & page.
        $this->userUpdateDraftsQuery($page, $userId)->delete();
        // Save a revision after updating
        if ($oldHtml !== $input['html'] || $oldName !== $input['name'] || $input['summary'] !== null) {
            $this->saveRevision($page, $input['summary']);
        }
        return $page;
    }