One cURL does executing the other does - php

Question

Hey guys I'm working with PHP, cURL and JSON data.
Architecture:
FRONT <-> MIDDLE <-> BACK
Problem location:
MIDDLE <-> BACK
Description:
In my MIDDLE file (PHP server) I call a function which make a cURL to my BACK file (PHP server).
The issue I'm having is that it will execute one of the calls (HTTP cURL requests) but not the other, overthought the one not executing is the call first.
Can you guys guide me on the issue, how can I solve this?
What I've try:
I research (articles, videos) info on curl thinking that maybe I had to handle it mysql-like, in which I had to create multiple cURL connection if I needed to request different items from the same server (BACK).
I've implemented dummy print outs to see whats executed and came about the conclusion I describe in the description part.
Note:
Following you will find the code for MIDDLE, BACK and two images:
Image 1 is the code with dummy print out showing how one cURL executes and the other does not. Please noticed the text "what back gets".
Image 2 is how cURL is not executed.
MIDDLE FILE:
Note:
Look how under case "EXAMSOLVED" I call two functions. That is related to Image 1.
If I comment the second function that is related to Image 2.
<?php
/*------------------------------------------------------------------*/
include "exam_grading_system.php";
/*------------------------------------------------------------------*/
function http_post_back_server($url, $data)
{
$obj = curl_init();
curl_setopt($obj, CURLOPT_URL, $url);
curl_setopt($obj, CURLOPT_POST, strlen($data));
curl_setopt($obj, CURLOPT_POSTFIELDS, $data);
curl_setopt($obj, CURLOPT_RETURNTRANSFER, true);
$ans = curl_exec($obj);
curl_close($obj);
return $ans;
}
//--------------------------------------------------------------------
function get_question_info($ulr, $id_question)
{
//Set UP Request Packet
$askDB->case = "GradingInfo";
$askDB->id_question = $id_question;
//Convert Packet to JSON format
$askDB = json_encode($askDB);
//echo $askDB;
//Ask Back Server
$BK_Srv_Ans = http_post_back_server($url,$askDB);
return $BK_Srv_Ans;
}
//--------------------------------------------------------------------
/*URL TO BACK SERVER*/
$url_myserver = "https: MY URL ";
/*GLOBAL VARS*/
$back_ans ="";
/*RECEIVE DATA FROM POST REQUEST*/
$indata = file_get_contents("php://input");
$data = json_decode($indata,true);
/*MAKE REQUEST TO SERVERS*/
switch($data["case"]){
case "_EXAMSOLVED_":
$questions_Info = get_question_info($url_myserver, $data["id_question"]);
//$indata = Grading($data, $questions_Info);
//$back_ans = http_post_back_server($url_myserver,$indata);
break;
default:
$back_ans = http_post_back_server($url_myserver,$indata);
break;
}
/*ANSWER BACK TO FRON END*/
echo $back_ans;
?>
BACK FILE:
Note: Look the dummy echo statement I have at the begging of the file
<?php
/*------------------------------------------------------------------*/
include "Prof_backend_tools.php";
include "Student_backend_tools.php";
/*------------------------------------------------------------------*/
echo "what back gets: ";
/*RECEIVING DATA FROM POST REQUEST */
$indata = file_get_contents("php://input");
/*DATA TO JSON OBJ*/
$indata = json_decode($indata, true);
/*CHECKING DATABASE CONNECTIVITY */
if(mysqli_connect_error())
{ echo "Connection Error: ".mysqli_connect_error; }
switch($indata["case"])
{
case "_EXAMSOLVED_":
echo store_exam_slutions($indata,DB_s());
break;
case "GradingInfo":
echo "--IN BACK--";
//echo Needed_data_for_grading($indata);
break;
default:
echo "NADA";
break;
}
?>
Image 1:
Image 2:
Any guide would be great guys.
Thank you.

Answer 1

OK,I've found what was happening!!!
Debugging:
Check MIDDLE file.
Check the parameters in function definition get_question_info
Now check arguments given to function call http_post_back_server
There lies the problem.