ApiPlatform\SchemaGenerator\AnnotationGenerator\ConstraintAnnotationGenerator::generateFieldAnnotations PHP Method

    public function generateFieldAnnotations($className, $fieldName)
    {
        $field = $this->classes[$className]['fields'][$fieldName];
        if ($field['isId']) {
            return [];
        }
        $asserts = [];
        if (!$field['isArray']) {
            switch ($field['range']) {
                case 'URL':
                    $asserts[] = '@Assert\\Url';
                    break;
                case 'Date':
                    $asserts[] = '@Assert\\Date';
                    break;
                case 'DateTime':
                    $asserts[] = '@Assert\\DateTime';
                    break;
                case 'Time':
                    $asserts[] = '@Assert\\Time';
                    break;
            }
            if (isset($field['resource']) && 'email' === $field['resource']->localName()) {
                $asserts[] = '@Assert\\Email';
            }
            if (empty($asserts)) {
                $phpType = $this->toPhpType($field);
                if (in_array($phpType, ['boolean', 'float', 'integer', 'string'])) {
                    $asserts[] = sprintf('@Assert\\Type(type="%s")', $phpType);
                }
            }
        }
        if (!$field['isNullable']) {
            $asserts[] = '@Assert\\NotNull';
        }
        if ($field['isEnum']) {
            $assert = sprintf('@Assert\\Choice(callback={"%s", "toArray"}', $field['range']);
            if ($field['isArray']) {
                $assert .= ', multiple=true';
            }
            $assert .= ')';
            $asserts[] = $assert;
        }
        return $asserts;
    }