- Patch #367013 by bjaspan, KarenS | yched, Dries: add support for field updates.

1 files changed, 83 insertions, 0 deletions

diff --git a/modules/field/field.crud.inc b/modules/field/field.crud.inc
index 7f316c4db..210dad136 100644
--- a/modules/field/field.crud.inc
+++ b/modules/field/field.crud.inc
@@ -312,6 +312,89 @@ function field_create_field($field) {
   return $field;
 }
 
+/*
+ * Update a field.
+ *
+ * Any module may forbid any update for any reason. For example, the
+ * field's storage module might forbid an update if it would change
+ * the storage schema while data for the field exists. A field type
+ * module might forbid an update if it would change existing data's
+ * semantics, or if there are external dependencies on field settings
+ * that cannot be updated.
+ *
+ * @param $field
+ *   A field structure. $field['field_name'] must provided; it
+ *   identifies the field that will be updated to match this
+ *   structure. Any other properties of the field that are not
+ *   specified in $field will be left unchanged, so it is not
+ *   necessary to pass in a fully populated $field structure.
+ * @return
+ *   Throws a FieldException if the update cannot be performed.
+ * @see field_create_field()
+ */
+function field_update_field($field) {
+  // Check that the specified field exists.
+  $prior_field = field_read_field($field['field_name']);
+  if (empty($prior_field)) {
+    throw new FieldException('Attempt to update a non-existent field.');
+  }
+
+  // Use the prior field values for anything not specifically set by the new 
+  // field to be sure that all values are set.
+  $field += $prior_field;
+  $field['settings'] += $prior_field['settings'];
+
+  // Field type cannot be changed.
+  if ($field['type'] != $prior_field['type']) {
+    throw new FieldException("Cannot change an existing field's type.");
+  }
+
+  // Collect the new storage information, since what is in
+  // $prior_field may no longer be right.
+  $schema = (array) module_invoke($field['module'], 'field_schema', $field);
+  $schema += array('columns' => array(), 'indexes' => array());
+  // 'columns' are hardcoded in the field type.
+  $field['columns'] = $schema['columns'];
+  // 'indexes' can be both hardcoded in the field type, and specified in the
+  // incoming $field definition.
+  $field += array(
+    'indexes' => array(),
+  );
+  $field['indexes'] += $schema['indexes'];
+
+  $has_data = field_attach_field_has_data($field);
+
+  // See if any module forbids the update by throwing an exception.
+  foreach (module_implements('field_update_forbid') as $module) {
+    $function = $module . '_field_update_forbid';
+    $function($field, $prior_field, $has_data);
+  }
+
+  // Tell the storage engine to update the field. Do this before
+  // saving the new definition since it still might fail.
+  module_invoke(variable_get('field_storage_module', 'field_sql_storage'), 'field_storage_update_field', $field, $prior_field, $has_data);
+
+  // Save the new field definition. @todo: refactor with
+  // field_create_field.
+
+  // The serialized 'data' column contains everything from $field that does not
+  // have its own column and is not automatically populated when the field is
+  // read.
+  $data = $field;
+  unset($data['columns'], $data['field_name'], $data['type'], $data['locked'], $data['module'], $data['cardinality'], $data['active'], $data['deleted']);
+  $field['data'] = $data;
+
+  // Store the field and create the id.
+  $primary_key = array('id');
+  drupal_write_record('field_config', $field, $primary_key);
+
+  // Clear caches
+  field_cache_clear(TRUE);
+  
+  // Invoke external hooks after the cache is cleared for API consistency.
+  module_invoke_all('field_update_field', $field, $prior_field, $has_data);  
+}
+
 /**
  * Read a single field record directly from the database. Generally,
  * you should use the field_info_field() instead.