Programmatically render Block in a twig template drupal 8.

In drupal 7 syntax of render block in twig template is.

$block = module_invoke('module_name', 'block_view', 'block_delta');
print render($block['content']);

But now in drupal 8 syntax is changed, but first we have to install "Twig tweak" module that provides
a twig extension with useful functions an filters that can improve development experience.
here is the link for twig tweak module, please download from here..
https://www.drupal.org/project/twig_tweak
there will be cheat sheet for drupal 8 that helps in calling/render block or views in twig template file.

Drupal_view render..

Suppose we have to render/call view in twig template then syntax will be
{{ drupal_view('view_machine_name', 'block/page machine name') }}
Example:
{{ drupal_view('product_overview_video', 'block_2') }} 
here 'product_overview_video' is view machine name and 'block_2' is we created 2nd block on this view.

Drupal_block render..
Suppose we have to render/call block in existing block then our syntax will be
{{ drupal_block('block_machine_name', wrapper=false) }}
 Example:
{{ drupal_entity('block_content', 27) }}
here block_content is block machine name and 27 is block id.
OR
 {{ drupal_block('bartik_breadcrumbs') }}
we can direct call block by machine_name like breadcrumbs block. we just have to put the drupal_block function with machine_name and clear the cache and it will work.

Note: If have any suggestions or issue regarding 'Programmatically render Block in a twig template' then you can ask by comments.

User load by mail in drupal 8.

Yes, we can load the user detail by mail id in drupal 8. As per drupal syntax first we have to add user library for classes then we will user drupal load by mail function that is "user_load_by_mail()".

$check_user = user_load_by_mail($mailid);
 if (!empty($check_user)) {
     $uid = $check_user->id();
     $user_detail = \Drupal\user\Entity\User::load($uid);
                $user_id= $user_detail->get('uid')->value;
                $user_roles = $user_detail->getRoles();
                $user_status = $user_detail->isActive();
                $user_name = $user_detail->getUsername();
                $user_body = $user_detail->get('body')->value;               
                $user_email = $user_detail->get('mail')->value;
                $user_created_time = $user_detail->created->value;
                $user_field = $user_detail->get('field_machine_name')->value;  
                $user_loggedin_check = $user_detail ->login->value; // that will return 1 or 0
                if ($user_detail->login->value != 0) {
                    $first_login_data = date('Y-m-d H:i:s', $user_detail->login->value);
                } else {
                    $first_login_data = 'never';
                }
  }

Note: If have any suggestions or issue regarding 'User load by mail in drupal 8' then you can ask by comments.

Check twig file field is empty or not.

For check Twig file field is empty or not, look at the syntax..

 

{% if content.field_machine_name[0] is not empty %}
           /* write comment here */
{% else %}
          /* write comment here */
{% endif %}

                                 OR

{% if content.field_machine_name|render %}
       /* write comment here */
{% endif %}


Note: If have any suggestions or issue regarding 'Check twig file field is empty or not' then you can ask by comments.

New features in Drupal 8.

I am going to start describe few new things in Drupal 8 in easy way.

Now in drupal 8 version uses Symfony few Components, rather than all of Symfony. If you want to check the list of use components in druapl 8. You can check in 'core/composer.json' file.

1. We will render/call all variables of twig file in double Curly Braces/Brackets, Syntax..  {{ write variable name here }}   

      2. For comment in twig file we have to use # keyword, Syntax..  

          {#{ write variable name here }#}   or   {#  commenting syntax  #}

 Note: If have any suggestions or issue regarding 'New features in Drupal 8' then you can ask by comments.