Change Markdown to Wysiwyg editor in RainLab.Blog

To change the Markdown editor to Wysiwyg in Rainlab.Blog, you need to add the following code to your plugin in Plugin.php:

public function extendRainlabBlog(){
    Event::listen('backend.form.extendFields', function($widget) {
        // Extend only the Posts controller or Post model
        if (!$widget->getController() instanceof \RainLab\Blog\Controllers\Posts ||
            !$widget->model instanceof \RainLab\Blog\Models\Post){
            return;
        }
        // Update content field
        $widget->addSecondaryTabFields([
            'content' => [
                'tab' => 'rainlab.blog::lang.post.tab_edit',
                'type' => 'richeditor',
                'size' => 'huge',
                'stretch' => 'true'
            ]
        ]);
    });
}

And then call the method in boot():

public function boot(){
    $this->extendRainlabBlog();
}