Field config update code snippet for common settings

field_operations/readme.md

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+Code snippet to access & update field configs for _all_ created fields for a particular entity type, in this case node.

field_operations/update-all-fields.php

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+<?php
+
+/**
+ * Sets all non-title fields to optional.
+ */
+function hook_update_N() {
+  // Services we need.
+  $entityFieldManager = \Drupal::service('entity_field.manager');
+  $config = \Drupal::service('config.factory');
+
+  // Get all node fields.
+  $fields = $entityFieldManager->getFieldMap();
+  $fields = $fields['node'];
+  $base_fields = $entityFieldManager->getBaseFieldDefinitions('node');
+
+  // Pop off the entity key & generic fields (nid, uuid, revision_log, etc).
+  $fields = array_diff_key($fields, $base_fields);
+
+  // getFieldMap returns field names as the array key.
+  $keys = array_keys($fields);
+
+  // Loop through all fields, plus all bundles that a field is found on.
+  foreach ($keys as $key => $value) {
+    $field_name = $keys[$key];
+    $bundles = $fields[$value]['bundles'];
+
+    // In this example, we change every custom node field instance to be optional.
+    // Replace this with whatever specific code you need to change all field instances.
+    foreach ($bundles as $bundle) {
+      $config->getEditable("field.field.node.$bundle.$field_name")->set('required', FALSE)->save();
+    }
+  }
+
+}