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up vote 0 down vote favorite

I am trying to pass a Javascript variable to a PHP file using AJAX.

I have the below Javascript code;

<script type="text/javascript">
var route_id = 'travelling-from'; //Route ID

$('#'+route_id).change(function(e) {
    //Grab the chosen value on route change
    var selectroute = $(this).val();

    $.ajax({
        type: "GET",
        url: 'ajax-getvalues.php',
        data: { selectroute : selectroute }
    });
});
</script>

In my ajax-getvalues.php, I have;

$selectroute = mysqli_real_escape_string($connection, $_GET['travelling-from']);

When I try to use $selectroute, it seems to be empty.

Do I need to add something else in order for this to work? Or have I gone wrong at some point?

share|improve this question
2  
selectroute is the name that you're sending not travelling-from –  Musa Mar 11 at 16:43
    
also GET should be used to get data, use POST to send data. –  LJ_1102 Mar 11 at 16:53
1  
POST should be used when the client is sending data that will change the server's state (like a database update). GET may or may not be appropriate here as we have no idea what ajax-getvalues.php does. –  robbmj Mar 11 at 16:57
    
@robbmj you're right, I somehow was assuming this would update session data but it may aswell be a simple search query. –  LJ_1102 Mar 12 at 1:34

2 Answers 2

up vote 3 down vote accepted

When I try to use $selectroute, it seems to be empty

The AJAX request will be sent to ajax-getvalues.php with the query string:

?selectroute=somevalue

In PHP you are trying the get the value of a parameter called travelling-from, this parameter does not exist in the query string.

You need to change selectroute to travelling-from

$.ajax({
    type: "GET",
    url: 'ajax-getvalues.php?travelling-from=' + encodeURIComponent(selectroute)
});

Or of you prefer:

$.ajax({
    type: "GET",
    url: 'ajax-getvalues.php',
    data: {"travelling-from": encodeURIComponent(selectroute)}
});

This produces the query string ?travelling-from=somevalue which can now be accessed with $_GET['travelling-from']

share|improve this answer
    
Thanks for your suggestion, I added in the encodeURIComponent and I thought this had solved it but I am still having the same issue - it seems the selection value is being sent but not received by the PHP file - that is my guess anyway..? –  Sarah92 Mar 12 at 16:15
    
@Sarah92 my answer addressed your original question (why you couldn't get the value of travelling-from in PHP). Since then you have modified the question such that you are not asking the same question any more. I suggest that you roll-back to the original question and start a new one for this new issue. –  robbmj Mar 12 at 16:20
    
Ok I will start a new question thanks :) –  Sarah92 Mar 12 at 16:21
    
@Sarah92, you should undo the edit you made a few minutes ago as well. –  robbmj Mar 12 at 16:22
    
how do I undo my edit as I do not have the original code I posted anymore? –  Sarah92 Mar 12 at 16:24
up vote 0 down vote

In your example the key should be route_id instead of selectroute

<script type="text/javascript">
var route_id = 'travelling-from'; //Route ID

$('#'+route_id).change(function(e) { //Grab the chosen value on route change var selectroute = $(this).val();

var data = {};
data[route_id] = selectroute;
$.ajax({
                type: "GET",
                url: 'ajax-getvalues.php',
                data: data }
            }); </script>
share|improve this answer
    
Thanks for your response - I tried this suggestion and had no luck. It seems the value is being sent but not received in the PHP file...:( –  Sarah92 Mar 12 at 16:14
    
That's weird, just to be sure, you verified via console that that AJAX request is correct, right? But $_GET['travelling-from'] should then do the trick on the PHP side of things. Is there any proxy or something in between which might swallow the HTTP param? –  SGD Mar 12 at 16:57
    
Your solution plainly does not work route_id is interpreted literally as the value route_id which would create a query string in the form of ajax-getvalues.php?route_id=somevalue –  robbmj Mar 13 at 20:05
    
Haha, you are of course right. I'll update the example. –  SGD Mar 13 at 20:13

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