How can I copy a body field from one node to another node?

Question

I'm trying to write a small module that copies the body content from one node to another node. The module does almost what it should and everything arrives so far. However, I have to open the node to be copied once, then save it and then open it again. Then it has taken over everything correctly. But I would like to have the field already copied when I open the node. Since this is my beginnings in module development, I would of course appreciate any tips. I am also sure that this can be done more elegantly.

/**
 * Implements hook_form_alter().
 */
function copy_fields_from_model_contract_form_alter(&$form, FormStateInterface $form_state, $form_id) {
  
  $nid = 6766;
  $node_storage = \Drupal::entityTypeManager()->getStorage('node');
  $node = $node_storage->load($nid);
  if ($nid == '6766') {
    $getcontract = $node->field_vertragsinhalt->value;
  }

  $nid = 6716;
  $node_storage = \Drupal::entityTypeManager()->getStorage('node');
  $node = $node_storage->load($nid);
  if ($nid == '6716') {
    if ($form_id == 'node_buch_anlegen_edit_form') {
      $node->field_vertragsinhalt->value = $getcontract;
      $node->body->format = 'full_html';
      $node->save();
      dpm("Testsetest");
    }
  }
}

Answer 1

Use hook_ENTITY_TYPE_prepare_form if you want to change a field value before the form is built for an existing node:

<?php

use Drupal\node\NodeInterface;
use Drupal\Core\Form\FormStateInterface;


/**
 * Implements hook_ENTITY_TYPE_prepare_form() for node entities.
 */
function mymodule_node_prepare_form(NodeInterface $node, $operation, FormStateInterface $form_state) {
  if ($operation == 'edit') {
    if ($node->id() == '6716') {
      $node->field_vertragsinhalt->value = $getcontract;
      $node->body->format = 'full_html';
      // don't save the node yet, it will be saved after submitting
    }
  }
}

For the more common case of setting field values when creating new nodes see Pre-populate an entity reference field (media image) when creating a node

Answer 2

Vielen dank dafür, dass war genau das was ich brauchte. Und ich habe das auch soweit hin bekommen in der node edit version:

<?php

use Drupal\node\NodeInterface;
use Drupal\Core\Form\FormStateInterface;


/**
 * Implements hook_ENTITY_TYPE_prepare_form() for node entities.
 */
function copy_fields_from_model_contract_node_edit_node_prepare_form(NodeInterface $node, $operation, FormStateInterface $form_state)
{

//TODO Build NID as array and go through with loop

  $nid = 6766;
  $node_storage = \Drupal::entityTypeManager()->getStorage('node');
  $node = $node_storage->load($nid);

  if ($nid == '6766') {
    $getcontract = $node->field_vertragsinhalt->value;
  }

  //TODO Works without ($operation == 'default')

  if ($operation == 'edit')  {
    dpm ("Modul an edit");
    //TODO Shall always pull the current node and nid. But does not work yet with node creation. Error: Call to a member function id() on null in

    $node = \Drupal::routeMatch()->getParameter('node');
    $nid = $node->id();
    $node_storage = \Drupal::entityTypeManager()->getStorage('node');
    $node = $node_storage->load($nid);

    if ($node->getType() == 'buch_anlegen') {
      dpm($nid);
      $node->field_vertragsinhalt->value = $getcontract;
      $node->body->format = 'full_html';
      // don't save the node yet, it will be saved after submitting
    }
  }
}

That also does what it is supposed to. Now I would like to write the content when the node is created. There the hook also geift so far.

I have edited for this:

 if ($operation == 'edit')

to

 if (($operation == 'edit')|| ($operation == 'default'))

But then it throws me an error in line 30:

$nid = $node->id();

Could it be that when a node is created at this point the ID is not yet assigned? Or do I have a knot in my head now somehow. I'm trying to use hook_entity_type_create for this geread. The example for this:

/**
 * Implements hook_ENTITY_TYPE_create() for 'node'.
 */
function mymodule_node_create(\Drupal\node\NodeInterface $node) {

  if ($node->getType() == 'my_content_type') {
    $media = \Drupal::entityTypeManager()->getStorage('media')->load(38);
    $node->field_image[] = $media;
  }

}

Or am I all wrong there? And how do I get this to fit my case? This is what I have so far:

<?php

use Drupal\node\NodeInterface;
use Drupal\Core\Form\FormStateInterface;


/**
 * Implements hook_ENTITY_TYPE_prepare_form() for node entities.
 */
function copy_fields_from_model_contract_node_create_node_create(NodeInterface $node)
{
//TODO Build NID as array and go through with loop

  $nid = 6766;
  $node_storage = \Drupal::entityTypeManager()->getStorage('node');
  $node = $node_storage->load($nid);

  if ($nid == '6766') {
    $getcontract = $node->field_vertragsinhalt->value;
  }

  //TODO Works without ($operation == 'default')

  if ($node->getType() == 'mustervertrage') {
    /*dpm ($node->field_vertragsinhalt->value);*/
    //TODO Shall always pull the current node and nid. But does not work yet with node creation. Error: Call to a member function id() on null in

//        $node = \Drupal::routeMatch()->getParameter('node');
//        $nid = $node->id();
    $node_storage = \Drupal::entityTypeManager()->getStorage('node');
    $node = $node_storage->load($nid);

    if ($node->getType() == 'mustervertrage') {
      dpm($nid);
      $node->field_vertragsinhalt->value = $getcontract;
      $node->body->format = 'full_html';
      // don't save the node yet, it will be saved after submitting
    }
  }
}