Code

Add html after a field

(#field_prefix and #field_suffix).

If there no data, You can use field_update_field (tested on D7) Like:

Drupal 8 Hook System

Create a new Plugin Type in Drupal 8

Example from Drupal 8 example module, Thank you.

See the Drupal 8 'Example' contrib module for full details and source

Module name : 'plugin_type_example'

 

Drupal 8 introduces the concept of services to decouple reusable functionality and makes these services pluggable and replaceable by registering them with a service container.

 

Plugins are small pieces of functionality that are swappable. Plugins that perform similar functionality are of the same plugin type.

Link : https://www.drupal.org/developing/api/8/plugins

The database settings (and connection) has 3 levels.

1. KEY

2. TARGET

3. DATA

Example:

$databases[KEY][TARGET] = array (

 DATA

);

Like:

Compilers

1. COMPASS

Compass is a powerfull command line compiler

Install (Linux debian) : sudo apt-get install ruby-compass

Link : http://compass-style.org/help/documentation/command-line/

2. Koala

Use drupal 8 httpClient to read URL.

// Drupal httpClient.

$http = \Drupal::httpClient();

$url = 'http://example.com/';

Example:

$options = array();

$result = $http->request('get', $url, $options);

Example 1 : With DOMDocument: (Fast (0.0002 sec) but can have php warning)