Php – Uncaught TypeError: Cannot read property ‘data’ of undefined

ajaxjqueryPHP

I need some help with this code, I have found some similar issues:

Uncaught TypeError: Cannot read property 'value' of undefined

Uncaught TypeError: Cannot read property 'name' of undefined

Ajax call in jQuery – uncaught typeerror cannot read property 'error' of null

but still not working, I'm using jquery (.ajax) to send and recieve data to the server (php), when I use localhost at url in .ajax function, it works fine and receives the data that I need, but when I change the url for the ip of the server it shows: "Uncaught TypeError: Cannot read property "some value" of undefined"

Jquery code:

$(document).on("ready",inicio);

function inicio(){



  /*Change pages events*/
  var buttonscan;
  buttonscan = $('#button_scan');
  buttonscan.on("click",solicitardatos);



}

function solicitardatos(){
           var idscan = "001";
            $.ajax({
                type: 'post',
                //with localhost works fine, this is the ip of my cpu when testing from
                //other device 192.168.0.101
                url: "http://192.168.0.101/server/info.php?jsoncallback=?",
                data: {datos:idscan},
                cache: false,
                success: function(data) {


                $('#button_scan').hide();
                $('#page1').hide();
                $('#page2').show(); 


                $('#pl').html(data[0].pl);                 
                $('#name').html(data[0].name);


            },
            error: function(jqXHR, textStatus, errorThrown) {
                console.log("Error... " + textStatus + "        " + errorThrown);
                alert("Error... " + textStatus + "        " + errorThrown);
            },
            dataType: 'json'
        });

}

And this is the PHP server file (info.php)

<?php 
header('Content-Type: text/javascript; charset=UTF-8');

error_reporting(E_ALL ^ E_NOTICE);
require("conexion.php");


$id = $_POST['datos']; 

/*Here is all the sql statements, and the mysqli query*/

while ($fila = mysqli_fetch_array($peticion)) {

    $resultado[] = array("pl"=>$fila['pl'],"name"=>$fila['name']);  
}



mysqli_close($conexion);
//echo json_encode($resultado);
echo $_GET['jsoncallback'] . '(' . json_encode($resultado) . ');';

?>

So when I use the url setting (localhost) it works, when I change to the server ip (192.168.0.101) it stops working and shows:
"Uncaught TypeError: Cannot read property 'pl' of undefined"

, I know that the ip it is working because when I copy 192.168.0.101/server/info.php at my browser it doesn't shows any error

Thanks,

Now I have used an external server, which is in cloud, and it works if I use a constant $id = "001" at info.php, but when I removed that constant and put $id = $_POST['datos'] ,is empty again, so I think there is something wrong when sending the data

Best Answer

I think there are two things to fix:

PHP:

< header('Content-Type: text/javascript; charset=UTF-8');
> header('Content-Type: application/json; charset=UTF-8');

jQuery:

$.ajax({
    type: 'post',
    url: "http://192.168.0.101/server/info.php?jsoncallback=?",
    data: {datos:idscan},
    + contentType : "application/json"
    + dataType: "json"
    cache: false,

Warning: Cannot modify header information - headers already sent

Happens when your script tries to send an HTTP header to the client but there already was output before, which resulted in headers to be already sent to the client.

This is an E_WARNING and it will not stop the script.

A typical example would be a template file like this:

<html>
    <?php session_start(); ?>
    <head><title>My Page</title>
</html>
...

The session_start() function will try to send headers with the session cookie to the client. But PHP already sent headers when it wrote the <html> element to the output stream. You'd have to move the session_start() to the top.

You can solve this by going through the lines before the code triggering the Warning and check where it outputs. Move any header sending code before that code.

An often overlooked output is new lines after PHP's closing ?>. It is considered a standard practice to omit ?> when it is the last thing in the file. Likewise, another common cause for this warning is when the opening <?php has an empty space, line, or invisible character before it, causing the web server to send the headers and the whitespace/newline thus when PHP starts parsing won't be able to submit any header.

If your file has more than one <?php ... ?> code block in it, you should not have any spaces in between them. (Note: You might have multiple blocks if you had code that was automatically constructed)

Also make sure you don't have any Byte Order Marks in your code, for example when the encoding of the script is UTF-8 with BOM.

Javascript – Uncaught TypeError: Cannot read property ‘ownerDocument’ of undefined

Make sure you're passing a selector to jQuery, not some form of data:

$( '.my-selector' )

not:

$( [ 'my-data' ] )

Best Answer

Related Solutions

Php – Reference – What does this error mean in PHP

Warning: Cannot modify header information - headers already sent

Javascript – Uncaught TypeError: Cannot read property ‘ownerDocument’ of undefined

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