php global variables in ajax

Question

So i have a page called user.php as test

<?php 
$user = $_GET['userID'];
echo $user;
?>

then i have .js that uses ajax to add a comment on the profile which works but the php that it uses (select and insert) is in a file called profileComments.php

$.ajax({
        url: 'profileComments.php',
        method: 'POST',
        async: false,
        data: {
            display: 1,
            user: userID
        },
        success: function () {
            insertComments();
        }
    });

now i want to edit the select query of that profileComments.php file to only display those with the right userID

<?php
include "db.php";
$user = $_GET['userID'];

if (isset($_POST["display"])) {
  $comments= "SELECT * FROM comments";
  $query= mysqli_query($connection, $comments);

  while ($comments = mysqli_fetch_assoc($query)) { ?>
        <li>
            <?php echo $comments["content"]?>
        </li>
    <?php }
}

But the problem is when I edit it in

"SELECT * FROM comments WHERE userID = $user"

at the top i've written this $user = $_GET['userID']; but it gives me the unidentified error

How can i make this work?

it's not clear to me which script gets included into the other one. And which one is called via ajax. Can you please clarify that in your question? — Jeff, Jul 09 '18 at 19:01
You should probably show the code that calls `profileComments.php`. Also, there is no such thing as "an ajax file". AJAX stands for Asynchronous Javascript, and is a technology. — Patrick Q, Jul 09 '18 at 19:01
Without knowing your ajax call code, it could be `$_POST['userID'];` ... — IncredibleHat, Jul 09 '18 at 19:04
I updated the question with the ajax code and the profileComments — anonymous, Jul 09 '18 at 19:12
also in your success-callback you don't ever use the data which get's sent back from php. might be something like this: `success: function (html) { insertComments(html); }` — Jeff, Jul 09 '18 at 19:39
I tried to make a function with the get method but i just don't know how to fix this problem, like my URL is like this: /user.php?userid=1 and i don't know how to get the userid — anonymous, Jul 09 '18 at 20:08

score 1 · Answer 1 · answered Jul 09 '18 at 19:18

1

You're using AJAX to send a POST request, not a GET request (See the method value of your ajax request). Therefore, all of the data in that AJAX request will be read into the $_POST superglobal of PHP.

You also named that key 'user', not 'userID' (see the data value of your ajax request).

Try:

$user = $_POST['user'];

answered Jul 09 '18 at 19:18

Devon Bessemer

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I tried that but i still get the same error, just want to get the user from the URL and i thought $_GET would do that job but i'm new to this and yea still wondering how to make it work – anonymous Jul 09 '18 at 19:27
You tried `$_POST['user']`? Because that matches your code. If you want to put it in the URL, then put it in the URL. You could set the AJAX url to `'profileComments.php?userID=' + userID` – Devon Bessemer Jul 09 '18 at 19:29
i'm not following? – anonymous Jul 09 '18 at 19:29
@anonymous It's very simple: POST data is put in `$_POST`, URL parameters are in `$_GET`. – Barmar Jul 09 '18 at 20:16
So on comments I added $user = $_POST["user"] and my Ajax now looks like this $.ajax({ url: 'profileComments.php?userID' + userID, method: 'POST', async: false, data: { display: 1, user: userID }, success: function () { insertComments(); } }); This still results in the same error, so im not sure what I do wrong and I apologize that I'm asking a lot since im new to this – anonymous Jul 09 '18 at 22:15
@anonymous what's the exact error? You don't need to do both: Add userID to the URL to access `$_GET['userID']` or include user in the POST data to access `$_POST['user']`. Having userID included twice is redundant. – Devon Bessemer Jul 09 '18 at 22:40
Notice: Undefined index: userID in /path/to/directory/comment.php on line 3 and this is after putting $id = $_GET['id'] on the profileComments page and having url: 'profileComments.php?userID=' + userID in the Ajax call – anonymous Jul 09 '18 at 23:37
That's a different file than profileComments.php... Are you looking at the response of your ajax request for this error!? – Devon Bessemer Jul 10 '18 at 00:32
yes sorry I mistyped the name of the page in my reply here, but yes I'm looking at the response and it keeps giving me the undefined index error – anonymous Jul 10 '18 at 07:44
It has been fixed, I tried a workaround that I came up with to fix the issue, thanks for all the help it was a huge help to achieve this – anonymous Jul 10 '18 at 10:15

php global variables in ajax

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