Ajax Call keeps failing without error

Question

So my ajax call works fine, i get a green light next to it in web inspector and I see the correct parameters being sent back and JSON objects being returned. However, it automatically goes to ERROR. I added some error handling and have ran out of ideas..

Does anyone see anything??

Javascript

    function getMoreOlder(id) { 
        $.ajax({
            url: "getmore.php",
            type : "POST",
            dataType : "json",
            data: {
                postid : id,
                type: "later",
            },
           success: function(response){
               alert("Success");
              for (var i=0; i<json.length; i++) {
               //     alert("Loop");
                    }
          },
          error: function(jqXHR,error, errorThrown){
                   if(jqXHR.status&&jqXHR.status==400){
                        alert(jqXHR.responseText); 
                   }else{
                       alert("Something went wrong");
                   }
          }   
         });
    }

PHP Script

        $id = $_POST['postid'];
        $type = $_POST['type'];

        if($type == "later") {
        $sql = "CALL `sp_BlogPosts_PageByPostID`('" . $id ."')";
        $exec = mysqli_query($conn, $sql);

        while($fetch = mysqli_fetch_assoc($exec)) { 
           $obj = array(
             "PostID" => stripslashes(trim(mysqli_real_escape_string($conn, $fetch['PostID']))),  
             "Title" => stripslashes(trim(mysqli_real_escape_string($conn, $fetch['title']))),     
             "Content" => stripslashes(trim(mysqli_real_escape_string($conn, $fetch['content']))),     
             "Email" => stripslashes(trim(mysqli_real_escape_string($conn, $fetch['email']))),    
             "Username" => stripslashes(trim(mysqli_real_escape_string($conn, $fetch['username']))),    
             "Created_At" => stripslashes(substr(trim(mysqli_real_escape_string($conn, $fetch['created_at'])), 0 , 10)));
              echo json_encode($obj);
        }

Example Usage

  <button onClick="getMoreOlder(1113);"> Load More Posts </button>

Example Return

    {"PostID":"1177","Title":"Off track","Content":"Hi This is a Post", "Email":"me@yahoo.com", "Username":"Abc123", "Created_At":"12-2-14"}

Key Points

• Correct variables are being sent in POST

• Correct information is returned in POST

• Always returns error Something went wrong!

• Web Inspector shows 200 code for POST request

Answer 1

the problem is you are continually echoing out json_encode, this will make invalid json output.

For example:

{"PostID":"1177","Title":"Off track"}{"PostID":"1177","Title":"Off track"}

This is invalid json. So put all your data into an array/object and then echo json_encode

$objArr = array();
while($fetch = mysqli_fetch_assoc($exec)) { 
    $objArr[] = array(
        "PostID" => stripslashes(trim(mysqli_real_escape_string($conn, $fetch['PostID']))),  
        "Title" => stripslashes(trim(mysqli_real_escape_string($conn, $fetch['title']))),     
        "Content" => stripslashes(trim(mysqli_real_escape_string($conn, $fetch['content']))),     
        "Email" => stripslashes(trim(mysqli_real_escape_string($conn, $fetch['email']))),    
        "Username" => stripslashes(trim(mysqli_real_escape_string($conn, $fetch['username']))),    
        "Created_At" => stripslashes(substr(trim(mysqli_real_escape_string($conn, $fetch['created_at'])), 0 , 10))
    );          
}

echo json_encode($objArr);

Or as suggested in the comments fetch all the data at once and echo out that

echo json_encode($exec->fetch_all(MYSQLI_ASSOC));

Also your for loop is using the wrong variable

for (var i=0; i<json.length; i++) {

should be

for (var i=0; i<response.length; i++) {