Access field value for a node in Drupal

Access field value for a node in Drupal

use Drupal\node\Entity\Node

Working with nodes Load a node by NID:
	$nid = 123;     // example value

	Method 1
	$node_storage = \Drupal::entityTypeManager()->getStorage('node');
	$node = $node_storage->load($nid);

	Method 2
	$node = \Drupal\node\Entity\Node::load($nid);
  
Get node's :
  echo $node->id();  // 123
  echo $node->bundle();    // 'article'
	echo $node->getType();    // 'article' - this is the same as bundle() for most entities, 

Get a built-in field value: Method 1
  echo $node->get('title')->value;           // "Lorem Ipsum..."
	echo $node->get('created')->value;         // 1510948801
	echo $node->get('body')->value;            // "The full node body, with HTML"
	echo $node->get('body')->summary;          // "This is the summary"
	// a custom text field
	echo $node->get('field_foo')->value;       // "whatever is in your custom field"
	// a file field
	echo $node->get('field_image')->target_id; // 432 (a managed file FID)

	Method 2	
	echo $node->title->value;            // "Lorem Ipsum..."
	echo $node->created->value;          // 1510948801
	echo $node->body->value;             // "This is the full node body, with HTML"
	echo $node->body->summary;           // "This is the summary"
	echo $node->field_foo->value;        // "whatever is in your custom field"
	echo $node->field_image->target_id;  // 432
  
Get nodes from a query: get multile nodes values using query and loop, execute other activities for this node
  $query = \Drupal::entityQuery('node')
	->condition('type', 'article'),
	->condition('field_foo', 42);
	$nids = $query->execute();
	$nodes = $node_storage->loadMultiple($nids);

	foreach ($nodes as $n) {
	echo $n->title->value;            // "Lorem Ipsum..."

	// do whatever you would do with a node object (set fields, save, etc.)
	$n->set('title', "this is a test");
	$n->save();
	}
  
Set fields value programatically for node
  $node->set('title', "Moby Dick");
	$node->set('body', array(
	'summary' => "Book about a whale",
	'value' => "Call me Ishmael...",
	'format' => 'basic_html',
	));
	$node->save();
  
Delete node programatically
  // one
	$nid = 42;      // example value
	$node = $node_storage->load($nid);
	$node->delete();
	 
	// multiple
	$nids = [21,12,45,67];  // example value
	$nodes = $node_storage->loadMultiple($nids);
	$node_storage->delete($nodes);
	 
	// multiple, loading one at a time to avoid "out of memory" errors - may be slow
	$nids = [21,12,45,67];  // example value
	foreach($nids as $nid)
	{
	  $node = $node_storage->load($nid);
	  $node->delete();
	}
  
Working with Paragraphs Paragraphs" (from the popular contrib module of the same name) are separate entities that are related to the parent nodes via an entity reference revision.
  $my_paragraph = null;
	foreach ($node->get('field_paragraph_reference') as $para) {
	  if ($para->entity->getType() == 'your_paragraph_type') {   // e.g., "main_content" or "social_media"
		$my_paragraph = $para->entity;
	  }
	}
	 
	if (!empty($my_paragraph)) {
	  // $my_paragraph is a regular entity and can be interacted with like any other entity
	  echo $my_paragraph->field_somefield->value;
	 
	  // (however, they don't have a "title" like a node)
	  echo $my_paragraph->title->value;  // <-- this won't work
	} else {
	  echo "The node doesn't have this paragraph type.";
	}	
  
Get a file by ID:
  $fid = 42;      // example value
	
	Method 1
	$file_storage = \Drupal::entityTypeManager()->getStorage('file');
	$file = $file_storage->load($fid);	
	
	Method 2
	$file = \Drupal\file\Entity\File::load($ffid);
	$fileSRC = file_create_url($file->getFileUri());
  
Get a file referenced in a node:
  $file = $node->field_image->entity;
  
Reading some properties from a File entity:
  echo $file->getFileUri();   // "public://file123.jpg"
	// if you want the URL without Drupal's custom scheme, you can translate it to a plain URL:
	echo file_url_transform_relative(file_create_url($file->getFileUri()));   // "/sites/default/files/public/file123.jpg"
	echo $file->filename->value;   // "file123.jpg"
	echo $file->filemime->value;   // "image/jpeg"
	echo $file->filesize->value;   // 63518  (size in bytes)
	echo $file->created->value;    // 1511206249  (Unix timestamp)
	echo $file->changed->value;    // 1511234256  (Unix timestamp)
	echo $file->id();              // 432	
  
The file's user data
  echo $file->uid->target_id;               // 1
	echo $file->uid->value;                   // <-- doesn't work. Use target_id instead.
	echo $file->uid->entity->name->value;     // "alice"
	echo $file->uid->entity->timezone->value; // "America/Los_Angeles"
  
Get file id
  $node->field_image->getValue();
  
Reading from entity reference fields that allow multiple values:
  foreach ($node->field_my_entity_reference as $reference) {
	  echo $reference->target_id;    // 1 (a node's nid)
	  echo $reference->entity->title->value;    // "Moby Dick" 
	}
  
Populate the value of an entity reference field which allows multiple values (this replaces any existing value in the DB)
  $nids = [3,4,5,6];   // example value
	$node->set('field_my_entity_reference', $nids);
	$node->save();
  
Append new referenced items to an entity reference field (this preserves existing values)
  $nids = [3,4,5,6];   // example value
	foreach ($nids as $nid) {
	  $node->field_my_entity_reference[] = [
		'target_id' => $nid
	  ];
	}
	$node->save();