Views exposed form programmatically and assign to somewhere

Sometimes to get the views exposed form and place into somewhere in the site. So we can use the below code to achieve programmatically.

$view = Views::getView('view_name');
$view->setDisplay('display_name');
$view->initHandlers();
$form_state = (new FormState())
  ->setStorage([
    'view' => $view,
    'display' => &$view->display_handler->display,
    'rerender' => TRUE,
  ])
  ->setMethod('get')
  ->setAlwaysProcess()
  ->disableRedirect();
$form_state->set('rerender', NULL);
$form = \Drupal::formBuilder()->buildForm('\Drupal\views\Form\ViewsExposedForm', $form_state);

Download drupal contributed module in Drupal 8 using composer

Use the following commands to download and install in drupal 8 contributed module using Composer.

composer require drupal/{module_name} {version}

Example: composer require drupal/devel 1.0-beta1

Once execute the above command, this will download the module (not installed). For install, we need the execute the drush or drupal console command to install the module.

Via Drush: drush en {module_name}
Via Drupal console: drupal module:install {module_name}

Clear the cache in Drupal 8

We can clear the cache in Drupal 8 in many ways

1. Via CMS end
Go to Administration > Configuration > Development > Performance (/admin/config/development/performance)
Click the button "Clear all caches"

2. Drupal console
drupal cache:rebuild all

3. Drush
drush cache-rebuild / drush cr

Create custom module in Drupal 8 via Drupal console

Generate module 
 drupal generate:module - It will ask the module name and basic information.

Give the module a name of module (welcome) and Enter module description, path and basic information. Then drupal will create the below files under the your custom module.

composer.json
welcome.info.yml
welcome.module

Install module

The module now exists but it is not enabled. You don’t need to go to the module page to enable it, you can install and enable the welcome module using the module:install command:

drupal module:install welcome

This will install the module and automatically rebuild the cache.

List out CCK field allowed values in Drupal

List out CCK field allowed values in Drupal

$field = field_info_field('field_machine_name');
$allowed_values = list_allowed_values($field);

This will return the allowed values list as array.

Usage:
field_info_field - Load the field instance by using field machine name
list_allowed_values - List out the allowed values