Codeigniter发送空白页

Question

I faced today a strange problem wich I cannot explain. The Environment:

• Ubuntu 16.04
• Nginx 1.10 with php-fpm
• php 7.0.8

So I migrated from a hosted server with apache and php5 to this new Server. The first tests were successful. The page was running and seemed to be fine.

Then I encountered the Problem, that some pages couldn't be called. The HTTP response was 200 but the page was blank. Chrome told me net::ERR_CONTENT_DECODING_FAILED

I found out, that the difference between working pages and the blank pages were, that the non-controller echoed json_encode() at the end;

This is my controller:

public function some_controller()
{
     $result = ["test" => "abcde"];
     echo json_encode($result);
}

This will end with net::ERR_CONTENT_DECODING_FAILED

This is my workarround:

public function some_controller()
{
     $result = ["test" => "abcde"];
     echo json_encode($result);
     exit();
}

So following is unclear:

1. Why I have to exit() my controller now?
2. What is CI doing after a Controller function is passed?
3. Why was that working with Apache and PHP5? What could be the difference now?

Thank you all

Answer 1

I found the problem by myself. After installing php7.0-xml the issue went away.

But can anyone tell me why the xml module is required for JSON responses? Maybe its not the JSON, it is codeigniter wich needs the XML Module (After the controller is passed)?