using jquery post to send values to php file - php

Question

I'm trying to write a script in javascript/jquery that will send values to a php file that will then update the database. The problem is that the values aren't being read in by the PHP file, and I have no idea why. I hard-coded in values and that worked fine. Any ideas?
Here's the javascript:
var hours = document.getElementById("hours");
var i = 1;
while(i < numberofMembers) {
var memberID = document.getElementById("member"+i);
if(memberID && memberID.checked) {
var memberID = document.getElementById("member"+i).value;
$.ajax({
type : 'post',
datatype: 'json',
url : 'subtract.php',
data : {hours : hours.value, memberID : memberID.value},
success: function(response) {
if(response == 'success') {
alert('Hours subtracted!');
} else {
alert('Error!');
}
}
});
}
i++;
}
}
subtract.php:
if(!empty($_POST['hours']) AND !empty($_POST['memberID'])) {
$hoursToSubtract = (int)$_POST['hours'];
$studentIDString = (int)$_POST['memberID'];
}
$query = mysql_query("SELECT * FROM `user_trials` WHERE `studentid` = '$studentIDString' LIMIT 1");
Edit: Updated code following #Daedal's code. I'm still not able to get the data in the PHP, tried running FirePHP but all I got was "profile still running" and then nothing.

Answer 1

This might help you:
function subtractHours(numberofMembers) {
var hours = document.getElementById('hours');
var i = 1;
while(i < numberofMembers) {
// Put the element in var
var memberID = document.getElementById(i);
// Check if exists and if it's checked
if(memberID && memberID.checked) {
// Use hours.value and memberID.value in your $.POST data
// {hours : hours.value, memberID : memberID.value}
console.log(hours.value + ' - ' + memberID.value);
// $ajax is kinda longer version of $.post api.jquery.com/jQuery.ajax/
$.ajax({
type : 'post',
dataType : 'json', // http://en.wikipedia.org/wiki/JSON
url : 'subtract.php',
data : { hours : hours.value, memberID : memberID.value},
success: function(response) {
if( response.type == 'success' ) {
alert('Bravo! ' + response.result);
} else {
alert('Error!');
};
}
});
}
i++;
}
}
and PHP part:
$result = array();
// Assuming we are dealing with numbers
if ( ! empty( $_POST['hours'] ) AND ! empty( $_POST['memberID'] ) ) {
$result['type'] = "success";
$result['result'] = (int) $_POST['hours'] . ' and ' . (int) $_POST['memberID'];
} else {
$result['type'] = "error";
}
// http://php.net/manual/en/function.json-encode.php
$result = json_encode( $result );
echo $result;
die();
Also you probably don't want to CSS #ID start with a number or to consist only from numbers. CSS Tricks explained it well http://css-tricks.com/ids-cannot-start-with-a-number/
You can simple fix that by putting some string in front:
var memberID = document.getElementById('some_string_' + i);
This is not ideal solution but it might help you to solve this error.
Cheers!
UPDATE:
First thing that came to my mind is that #ID with a number but as it seems JS don't care about that (at least not in a way CSS does) but it is a good practice not to use all numbers. So whole error was because document.getElementById() only accepts string.
Reference: https://developer.mozilla.org/en-US/docs/DOM/document.getElementById id is a case-sensitive string representing the unique ID of the element being sought.
Few of the members already mentioned converting var i to string and that was the key to your solution. So var memberID = document.getElementById(i); converts reference to a string. Similar thing could
be accomplished I think in your original code if you defined wright bellow the loop while(i < numberofMembers) { var i to string i = i.toString(); but I think our present solution is better.

Answer 2

Try removing the '' fx:
$.post (
"subtract.php",
{hours : hours, memberID : memberID}

Answer 3

try this
$.ajax({type: "POST",
url:"subtract.php",
data: '&hours='+hours+'&memberID='+memberID,
success: function(data){
}
});

Answer 4

Also you could try something like this to check
$(":checkbox").change(function(){
var thisId = $(this).attr('id');
console.log('Id - '+thisId);
});

Answer 5

$studentID = $_GET['memberID'];
$hoursToSubtract = $_GET['hours'];

Answer 6

Try this:
$.post("subtract.php", { hours: hours, memberID : memberID })
.done(function(data) {
document.body.style.cursor = "auto";
});

Answer 7

Try n use this...
$.post("subtract.php", { hours: hours, memberID : memberID })
.done(function(data) {
$(body).css({ 'cursor' : 'auto' });
});