Programmatically User load and User load Multiple in drupal 8.

In drupal 8 User::load, we have to use library and calling name spaceuse Drupal\user\Entity\User;

So same as node::load, we can use User::load($userid);
or
we can direct call \Drupal\user\Entity\User::load($userid);

For get the user detail fields by User::load($userid) syntax is..

Example: This example is for single user load.
                $user_detail = User::load($userid);       
                                    OR
                $user_detail = \Drupal\user\Entity\User::load($userid);
           
                $user_id= $user_detail->get('uid')->value;
                $user_roles = $user->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;  

Example: This example is for multiple user load.
First you have to use user library and calling name space
use  \Drupal\user\Entity\User;

                $users = User::loadMultiple($ids);
                foreach($users as $u) {
                   $users_mailid= $u->getEmail();
                   $user_id= $u->get('uid')->value;
                   $user_name = $u->getUsername();
                   $field_value = $u->get('field_machine_name')->value;
                 } 

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

Page Redirection programmatically in drupal 8.

In drupal 8 for page redirection, we have to use Symfony components class. Here page redirection is done by 'RedirectResponse' class from Symfony HttpFoundation. In drupal 7 we using drupal_goto() function for redirect.
But in case of drupal 8, RedirectResponse' class is..

use Symfony\Component\HttpFoundation\RedirectResponse;

and suppose redirection page is node 2691 so we will give redirect url is '/node/2691'.
Example:
$url = '/node/2691';
return new RedirectResponse($url);

               OR

$redirect_variable = new Symfony\Component\HttpFoundation\RedirectResponse('/node/2691');     $redirect_variable ->send();
 return;

     For front page redirection, we can use..

return new \Symfony\Component\HttpFoundation\RedirectResponse(\Drupal::url('<front>'));

             OR
 In Function we can use redirect..
 public function submitForm(array &$form, FormStateInterface $form_state) {
   $form_state->setRedirect('redirect router name');
Example:
  $form_state->setRedirect('account_login.content');
 }

Note: If have any suggestions or issue regarding 'Page Redirection programmatically in drupal 8' then you can ask by comments.

Custom login create in drupal 8.

We are trying to clear the code of custom login with authentication. here we have the code.

 // Authentication of username and password..
$uid = \Drupal::service('user.auth')->authenticate($username,$password);
// Get the user id by database and load..
$user = \Drupal\user\Entity\User::load($uid);
// finally pass the user detail array in user login function..
 user_login_finalize($user);

Example:
 Like we have username and password by POST method and fields are.
<input id="login-username" type="text" class="form-control" name="name" value="" placeholder="username">
<input id="login-password" type="password" class="form-control" name="pass" placeholder="password">

so for got these credentials in function the code is.
$username = \Drupal::request()->request->get('name'); // form username
$password = \Drupal::request()->request->get('pass'); // form password

And the final code for login..

 $uid = \Drupal::service('user.auth')->authenticate($username,$password);
 $user = \Drupal\user\Entity\User::load($uid);
 user_login_finalize($user);
 
Note: If have any suggestions or issue regarding 'Custom login create in drupal 8' then you can ask by comments.

Get the current logged in user detail.

We have the syntax of current logged-in user detail, Please have a look.

1. Logged-in user id :    $uid = \Drupal::currentUser()->id();
2. Current User Detail Array :     $current_user_detail = \Drupal::currentUser();
3. Current Logged-in User Role Array: $current_user_role = \Drupal::currentUser()->getRoles();     
If we have multiple roles for single user and we have to check one role is exist or not in roles array.
Syntax..
if(in_array("my_role", $current_user_role )){         
   \\ my role exist in this array..
}

4. Current User Default Language : $langcode = \Drupal::currentUser()->getPreferredLangcode();

 
Note: If have any suggestions or issue regarding 'Get the current logged in user detail' then you can ask by comments.

Render view fields in custom view template in drupal 8.

First we have to create view according to our requirement and then create the custom view template file, suppose our view machine name is 'customer_story' and on 'block_1', so our template file name will be 'views-view-fields--customer-story--block-1.html.twig'.
and we can render our views fields variables like..

{{ fields.title.content }} //for title field
{{ fields.field_machine_name.content }} //for any other field render.
{{ file_url(fields.field_landing_page_image.content) }} //for image field render
{{ fields.field_page_url.content }}  //for link field render

you can get these variable name by 'custom text field' "Replacement pattern" settings.

Note: If have any suggestions or issue regarding 'Render view fields in custom view template in drupal 8' then you can ask by comments.

Loop in twig file drupal 8.

Here we have syntax of for/foreach loop in Twig file. Please have a look the syntax..
Suppose we have array with name of 'data', so our for loop for twig will be.

{% for key, value in data %}
      {{ key }} | {{ value }}
{% endfor %}

                      OR

In case we need key with value then our syntax will be..

<ul>
 {% for key, value in data %}
   {% if key!= ' '%}

      <li class="{{ key }}"> {{ value }}</li>
    {% endif %}
{% endfor %}
</ul>

                       OR

In case we just need value without key then our syntax will be..

{% for value in data %}
   {{ value }}     
{% endfor %}

Note: If have any suggestions or issue regarding 'Loop in twig file drupal 8' then you can ask by comments.

Drupal 8 base_path and base_path_url.

We have syntax change in drupal 8 for base_path and base_path_url, Please have a look..

• base_path = base_path();  // This code is for base_url of site.                                                    
• base_path_url = \Drupal::request()->getpathInfo();  // This code for current page path.
• Front page = {{ url('<front>') }}  // This code is for front page url.
• Theme directory path = url('{{ base_path ~ directory }} //This code is for theme's root directory

Note: If have any suggestions or issue regarding 'Drupal 8 base_path and base_path_url' then you can ask by comments.