Code

Example with CKEditor WYSIWYG inline images field.

Also see : Create a Form with Drupal 8 using Form API

Draggable table Form Example

Step 1 : Form build

Example: settings for local environnement.
Create the local settings file : local.services.yml the add to local settings.php file

# Local service config
$settings['container_yamls'][] = DRUPAL_ROOT . '/sites/default/local.services.yml';

Step 1 : Add the package cweagans/composer-patches
composer require cweagans/composer-patches

Doc : https://www.drupal.org/docs/drupal-apis/form-api/conditional-form-fields

States that can be applied to a form field element:

Import configuration file programmatically on Drupal 9 using config_update contrib module and service

//Update Module settings
\Drupal::service('config_update.config_update')->revert('system.simple', 'mymodule.settings');

State servic eallow to store variables such as state of the server temporarily or permanently

Examples:

Drupal settings file can contains variable which can use to use for different configuration in different environments.

Example:
env_name
default_info_nid

$settings['env_name'] = 'Local';
$settings['default_info_nid'] = 1';

You can use IMCE to select a file.

Method 1 : Form hook_page_attachments