Drupal 8 tweaks

d8.php

<?php
// thx drupal8.ovh
////  1) How to get the current language in Drupal 8

//To get the lanuage code:
$language = \Drupal::languageManager()->getCurrentLanguage()->getId();

//To get the language name:
$language =  \Drupal::languageManager()->getCurrentLanguage()->getName();

//// 2) Create a node programmatically (node type: article)

$language = \Drupal::languageManager()->getCurrentLanguage()->getId();
$node = \Drupal\node\Entity\Node::create(array(
          'type' => 'article',
          'title' => 'The title',
          'langcode' => $language,
          'uid' => 1,
          'status' => 1,
          'body' => array('The body text'),
          'field_date' => array("2000-01-30"),
            //'field_fields' => array('Custom values'), // Add your custon field values like this
    ));
$node->save();

//// 3) Create a user account programmatically

$language = \Drupal::languageManager()->getCurrentLanguage()->getId();
    $user = \Drupal\user\Entity\User::create();

//Mandatory settings
    $user->setPassword('password');
    $user->enforceIsNew();
    $user->setEmail('email');
    $user->setUsername('user_name');//This username must be unique and accept only a-Z,0-9, - _ @ .

//Optional settings
    $user->set("init", 'email');
    $user->set("langcode", $language);
    $user->set("preferred_langcode", $language);
    $user->set("preferred_admin_langcode", $language);
    //$user->set("setting_name", 'setting_value');
    $user->activate();

//Save user
    $res = $user->save();

//// 4) Get taxonomy vocabulary list

$vocabularies = \Drupal\taxonomy\Entity\Vocabulary::loadMultiple();

//// 5) Get taxonomy terms of a vocabulary

//Using entityQuery, you can get the taxonomy terms  of a particular vocabulary.

    $query = \Drupal::entityQuery('taxonomy_term');
    $query->condition('vid', "tags");
    $query->sort('weight');
    $tids = $query->execute();
    $terms = \Drupal\taxonomy\Entity\Term::loadMultiple($tids);

//If you want to get several vocabulary, use OR condition like that.
    $query_or->condition('vid', "tags");
    $query_or->condition('vid', "test");
    $query->condition($query_or);

//Get Taxonomy name
      $name = $term->toLink()->getText();

//Create link to the term
      $link = \Drupal::l($term->toLink()->getText(), $term->toUrl());

// !!! Get name & tid from loaded terms
foreach ($terms as $term) {
    $name = $term->get('name')->getString();
    $tid = $term->get('tid')->getString();
}

//// 6) Add CSS stylesheets to a module

/*
1. Styling a programmatically created block.
1.1 Add a librarie.
 -> Create a file modulename.libraries.yml
-> Add css file, Example: */
my-block-styling:
  version: 1.x
  css:
    theme:
      css/style.css: {}
/*
1.2 Create CSS file and put it in to the module_folder/css/style.css
1.3 Attach librarie to the block
In your build() methode, add to the output array,
*/

$output[]['#attached']['library'][] = 'modulename/my-block-styling';

// Add / Attaching a library from a Twig template
{{ attach_library('MODULENALE/my-style') }}

/* To remove a style sheet
stylesheets-remove: */
  - '@classy/css/components/tabs.css'
  - core/assets/vendor/normalize-css/normalize.css
    
//// 7) Get the current page URI
    
    $current_url = Url::fromRoute('<current>');
    $path = $current_url->toString();

// Examples for the page /en/user/login:
$current_url->toString(); // /en/user/login
$current_url->getInternalPath(); // user/login
$path = $current_url->getRouteName(); // <current>

// Drupal provide several way to do the same things, You can also use following syntax.
$path = \Drupal::request()->attributes->get('_system_path');
$current_uri = \Drupal::request()->getRequestUri();
$current_path = \Drupal::service('path.current')->getPath();
$result = \Drupal::service('path.alias_manager')->getAliasByPath($current_path);

// Get the url of the request
// This return the url displayed on the browser.
$page = \Drupal::request()->getRequestUri();

//// 8) Create a link with Drupal 8 like l() and url() on D7

$link = \Drupal\Core\Link::fromTextAndUrl($text, $url);

//// № 9) Return JSON array as resut

//Example 1.
return new \Symfony\Component\HttpFoundation\JsonResponse($array);

//Example 2.
use Symfony\Component\HttpFoundation\JsonResponse;
  public function get_result() {
    $output = array();
    $output[] = array('time' => date("Y-m-d H:i:s"));
    $output[] = array('result'=> "OK");
    return new JsonResponse($output);
  }

//// № 10) Create taxonomy term programmatically

$term = \Drupal\taxonomy\Entity\Term::create([
          'vid' => 'test_vocabulary',
          'name' => 'My tag',
    ]);
$term->save();

// With options

$term = \Drupal\taxonomy\Entity\Term::create([
          'vid' => 'test_vocabulary',
          'langcode' => 'en',
          'name' => 'My tag',
          'description' => [
            'value' => '<p>My description.</p>',
            'format' => 'full_html',
          ],
          'weight' => -1,
          'parent' => array(0),
    ]);
 $term->save();

//Add term with a custom field. Example : 'field_url'
$term = Term::create([
            'vid' => 'test_vocabulary',
            'name' => 'The Name',
            'field_url' => [$url],
      ]);
$term->save();

//Check Taxonomy name exist
    $query = \Drupal::entityQuery('taxonomy_term');
    $query->condition('vid', "test_vocabulary");
    $query->condition('name', "My tag");
    $tids = $query->execute();

//// № 11) Get the current user

    //use Drupal\user\Entity\User;
    $userCurrent = \Drupal::currentUser();
    $user = \Drupal\user\Entity\User::load($userCurrent->id());
    $name = $user->getUsername();

// How To check if the current page is the homepage
$is_front_page = \Drupal::service('path.matcher')->isFrontPage();


//// № 12) Get node id (NID) from url
$node = \Drupal::routeMatch()->getParameter('node');
if ($node) {
  $nid = $node->id();
}

//// № 13) Get field value of a Node / Entity

//1 : Example:

$value = $node->get($field)->value;
$target = $node->get($field)->target_id; // For entity ref

//2 Example:

$field = 'field_thefieldname';
$index = 0;  
$a = $node->toArray();
if (isset($a[$field][$index]['value'])) {
    $value = $a[$field][$index]['value'];
}

//3 : Get / Render image (Show current user's picture)

$userCurrent = \Drupal::currentUser();
$user = \Drupal\user\Entity\User::load($userCurrent->id());
$renderd_image = $user->get('user_picture')->first()->view();
Or for multiple values
foreach ($node->get('field_images')->getValue() as $key => $image) {
    $image = $node->field_images[$key]->view($settings);
}
//Example Of $settings
$settings = ['settings' => ['image_style' => 'thumbnail']];

//// № 14) Add a message to Drupal 8 Log system (/admin/reports/dblog)

        \Drupal::logger("mymodule")->alert("Message");
        \Drupal::logger("mymodule")->critical("Message");
        \Drupal::logger("mymodule")->debug("Message");
        \Drupal::logger("mymodule")->emergency("Message");
        \Drupal::logger("mymodule")->error("Message");
        \Drupal::logger("mymodule")->info("Message");
        \Drupal::logger("mymodule")->notice("Message");
        \Drupal::logger("mymodule")->warning("Message");

//// № 15) Update a node / Entity programmatically

//Example 1 : Update title
$node = \Drupal\node\Entity\Node::load($nid);
$node->setTitle('The new Title')
$node->save();

//Example 2 : Update a field ('body' and 'field_name')
$node = \Drupal\node\Entity\Node::load($nid);
$node->set("body", 'New body text');
$node->set("field_name", 'New value');
$node->save();

function mymodule_entity_presave(Drupal\Core\Entity\EntityInterface $entity) {
  if ($entity->getEntityType()->id() == 'node') {
    $entity->setTitle('The new Title');
    //CAUTION : Do not save here, because it's automatic.
  }
}

//// № 16) Create a custom permission in custom module (mymodule)

/* Step 1.
Create if not exist yet, mymodule.permissions.yml (root of mymodule)
Add your new permission like: */

mymodule test_permission:
    title: 'My Test Permission'
    description: 'The description'
    restrict access: false

/* Step 2.
On your mymodule.routing.yml */
mymodule.home:
  path: 'test/home'
  defaults:
    _controller: '\Drupal\mymodule\Controller\Test::home'
    _title: 'My test Home'
  requirements:
    _permission: 'mymodule test_permission'

//Set permissions on : /admin/people/permissions
      
//// № 17) Get args from URL
              
 $current_url = Url::fromRoute('<current>');
 $path = $current_url->toString();
 //OR of you want to get the url without language prefix
 $path = $current_url->getInternalPath();
 $path_args = explode('/', $path);

//Method 2: (Get first argument from url on Drupal 8)

$request = \Drupal::request();
$current_path = $request->getPathInfo();
$path_args = explode('/', $current_path);
$first_argument = $path_args[1];  

//// № 18) Page Redirect

return new \Symfony\Component\HttpFoundation\RedirectResponse('/node/17/edit');
return new \Symfony\Component\HttpFoundation\RedirectResponse(\Drupal::url('<front>'));
return new \Symfony\Component\HttpFoundation\RedirectResponse(\Drupal::url('user.page'));

//Form redirection on submit
//Redirect to the user page ( Redirection on form submit)
$form_state->setRedirect('user.page');

//Redirect to a custom page
$form_state->setRedirect('your.module.route.name');

 public function submitForm(array &$form, FormStateInterface $form_state) {
   $form_state->setRedirect('your.module.route.name');
  }
              
//// № 19) Add custom class to the elements of a Views

/**
 * Add classes to a view
 * @param $vars
 */
function MYTHEME_preprocess_views_view_list(&$vars) {
    if ($vars['view']->name == 'article') {
        $view = $vars['view'];
        foreach ($view->result as $row_index => $result) {
            $val1 = strlen($result->field_body[0]['rendered']['#markup']);
            $val2 = strlen($result->field_body[0]['raw']['safe_value']);
                $vars['classes_array'][$row_index] .= ' my-class';
        }
    }
}

//// № 20) Add twig template to a custom Module, Block or Page

https://www.drupal8.ovh/en/tutoriels/140/add-twig-template-to-a-custom-module-block-or-page

//// № 21) Call URL on Drupal 8, Like drupal_http_request() on D7

use GuzzleHttp\Exception\RequestException;
    $url = "http://www.domail.com";
    $client = \Drupal::httpClient();
    try {
      $response = $client->get($url);
      $data = $response->getBody();
      $code = $response->getStatusCode();
      $header = $response->getHeaders();
    }
    catch (RequestException $e) {
      watchdog_exception('my_module', $e);
    }
//https://www.drupal.org/node/1862446

//// № 22) JSON Encode and Decode

use Drupal\Component\Serialization\Json;
$json = Json::encode($data);
$data = Json::decode($json);

//// № 23) Change Drupal 8 text field maximum length

https://www.drupal8.ovh/en/tutoriels/223/change-drupal-8-text-field-maximum-length

//// № 24) Alter a view. Edit view result programmatically

function MYMODULE_views_pre_render(&$view) {
  if ($view->name == 'view_myviewname') {
    $result = $view->result;
    foreach ($result as $i => $row) {
      $view->result[$i]->field_field_myfieldtext[0]['rendered']['#markup'] = "The new text";
    }
  }
}


//// № 25) How to create a JSON web service

/* Create a module.
Here : mywebservice

Create route, the Web Service path.
Example: */
mywebservice.multiply:
  path: '/mywebservice/maths/multiply'
  defaults:
    _controller: '\Drupal\mywebservice\Controller\MyWebService::multiply'
    _title: 'MyWebService'
  requirements:
    _permission: 'access content'

/* Create webservice Controller
Example: */
// UNCOMMENT!!! <?php
//
namespace Drupal\mywebservice\Controller;
//
use Drupal\Core\Controller\ControllerBase;
use Symfony\Component\HttpFoundation\JsonResponse;
/**
 * Class MyWebService.
 */
class MyWebService extends ControllerBase {
  /**
   * Multiply.
   */
  public function multiply() {
    $request = \Drupal::request();
    $output['a'] = $request->get('a');
    $output['b'] = $request->get('b');
    $output['result'] = $output['a'] * $output['b'];
    return new JsonResponse($output);
  }
}
/*
Test the web service
Visit : http://yourdomain.loc/mywebservice/maths/multiply
Must return a JSON : {"a":null,"b":null,"result":0}

Visit : http://yourdomain.loc/mywebservice/maths/multiply?a=5&b=2
Must return a JSON : {"a":"5","b":"2","result":10}
*/

//// № 26) Change a metatag dynamicly

//Example: Add <meta http-equiv="refresh" content="30">
$data = [
  '#tag' => 'meta',
  '#attributes' => [
    'http-equiv' => 'refresh',
    'content' => '30',
  ],
];
$output['#attached']['html_head'][] = [$data, 'refresh'];

//// № 27) How more than 100 terms in taxonomy administration (overview) page

//Example : Show 1000 items on admin page.
//Check settings:
drush cget taxonomy.settings
//Set number to 1000:
drush cset taxonomy.settings terms_per_page_admin 1000


?>

This is awesome! Thanks. One thing I was wondering if you knew. How to create a vocabulary if it doesn't already exist. Might be worth adding.

$vid = "1";
    $name = "cars";
    $vocabularies = \Drupal\taxonomy\Entity\Vocabulary::loadMultiple();
    if (!isset($vocabularies[$vid])) {
      $vocabulary = \Drupal\taxonomy\Entity\Vocabulary::create(array(
            'vid' => $vid,
            //'machine_name' => $vid,
            'description' => '',
            'name' => $name,
      ));
      $vocabulary->save();
    }
    else {
      // Vocabulary Already exist
      $query = \Drupal::entityQuery('taxonomy_term');
      $query->condition('vid', $vid);
      $tids = $query->execute();
    }