Tutorials - Drupal

Create a custom module (here : example)

For active themes by route you first have to define a service in your $module.services.yml file:

On example.services.yml

Add:

Get the default cache bin

$cache = \Drupal::cache();

To get a particular cache bin (here 'render'):

$render_cache = \Drupal::cache('render');

Step 1: Activate RESTful Webservice

Active modules:
HAL (hal)
RESTful Web Services (rest)    
HTTP Basic Authentication (basic_auth)

Download and active contrib modules:
REST UI (restui)

You can call drupal 8 services statically as D7, but it is not the best practice (Like Here).
Example : $uuid = \Drupal::service('uuid')->generate();

Create a Service on Drupal 8

1.  Create a custom module (here : mytest)

2. Create the service Class
Example: src/MTService.php

Get All available services list

$services = \Drupal::getContainer()->getServiceIds();

Few use full services

//Generate a new UUID
$uuid = \Drupal::service('uuid')->generate();

Once created your entity as Basic Entity or Full Entity, you can add a custom views handler.

This is a full Example of the Entity 'Vehicle' with user interfaces for:
- Actions (Create, Edit, Delete)
- Listing builder
- Entity settings pages
   - Manage fields
   - Manage form display
   - Manage display

Drupal 8 has two type of entities, ContentEntity and ConfigEntity. Content entity is based on database table and config entity is based on Drupal config table.

Basic php and drupal 7 / 8 Examples

1.
$string_out = html_entity_decode($string, ENT_QUOTES, 'UTF-8')
//Do not forget ENT_QUOTES and 'UTF-8', otherwise quotes will not decodes.