function file_field_find_file_reference_column

Determine whether a field references files stored in {file_managed}.

Parameters

\Drupal\Core\Field\FieldDefinitionInterface $field: A field definition.

Return value

bool The field column if the field references {file_managed}.fid, typically fid, FALSE if it does not.

File

core/modules/file/file.field.inc, line 197

Code

function file_field_find_file_reference_column(FieldDefinitionInterface $field) {
    $schema = $field->getFieldStorageDefinition()
        ->getSchema();
    foreach ($schema['foreign keys'] as $data) {
        if ($data['table'] == 'file_managed') {
            foreach ($data['columns'] as $field_column => $column) {
                if ($column == 'fid') {
                    return $field_column;
                }
            }
        }
    }
    return FALSE;
}