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Creating a PHP session variable after successful AJAX call

I am having problems creating a PHP session following a successful AJAX call. Here is the AJAX code:
function onSignIn(googleUser) {
var profile = googleUser.getBasicProfile();
var id = profile.getId();
var em = profile.getEmail();
var name = profile.getName();
var pic = profile.getImageUrl();
var xhttp = new XMLHttpRequest();
xhttp.onreadystatechange = function() {
if (this.readyState == 4 && this.status == 200) {
document.getElementById('confirm-login').style.display = 'block';
}
};
xhttp.open("GET", "./assets/inc/profile.php?id="+id+"&e="+em+"&n="+name+"&p="+pic, true);
xhttp.send();
}
This part works perfectly. I only include it for completeness sake.
Here's the contents of profile.php
<?php
$id = $_GET["id"];
$email = $_GET["e"];
$name = $_GET["n"];
$pic = $_GET["p"];
require_once("db.php");
$result = $mysqli->query("SELECT googleid FROM user_tbl WHERE googleid = '$id' LIMIT 1");
if($result->num_rows == 0) {
$sql = "INSERT INTO user_tbl (googleid, email, fullname, pic, loc) VALUES ('$id', '$email', '$name', '$pic', '')";
if (mysqli_query($mysqli, $sql)) {
echo "New record created successfully";
} else {
echo "Error: " . $sql . "" . mysqli_error($mysqli);
}
} else {
echo "already exists";
}
$mysqli->close();
session_start();
$_SESSION['gid'] = $id;
?>
All of this code works except for session_start(); and $_SESSION['gid'] = $id; when I return to another PHP page (which correctly has session_start(); at the very top of the page) the variable has not been created in profile.php
Any help as to what I'm doing wrong would be much appreicated.

You can't start a session after the script has sent output. (There should have been output to that effect; if there wasn't, try changing PHP's warnings.) The session_start() call must come before any echo call that is actually executed.
On an unrelated topic, you will want to learn how to escape your database parameters.

Not able to read/pass JS value to server in PHP

I'm fetching value from Mysql in DropDown. Based on user selection a table should be populated.
But whatever I'm selecting in dropdown, it's not getting sent to server.
Please find below code:
Fetch value in dropdown
<?php
$result = mysqli_query($con, "SELECT name FROM restaurants;");
echo "<select name='sub1' id='resdropdown' onchange = 'showMenu(this.value)'>";
while ($row = mysqli_fetch_array($result)){
echo "<option value='" . $row['name'] ."'>" . $row['name'] . "</option>";
}
echo "</select>";
?>
Script to send value to server
function showMenu(str) {
/* var x = document.getElementById('resdropdown');
str = x.value;
alert(str); */
var ajax = new XMLHttpRequest();
var method = "GET";
var asynchronous = true;
var data = str;
ajax.open(method, "test.php?q="+data, asynchronous);
//sending ajax request
ajax.send();
ajax.onreadystatechange = function() {
if (this.readyState == 4 && this.status == 200) {
document.getElementById("testajaxid").innerHTML = this.responseText;
alert(str);
}
};
}
Get Response from server
$q = $_GET['data'];
$result = mysqli_query($con, "SELECT * FROM items where id = '".$q."'");
while($row = mysqli_fetch_array($result))
{
echo '<tr><td>'.$row["name"].'</td><td>'.$row["price"].'</td>';
echo '<td><div class="input-field col s12"><label for='.$row["id"].' class="">Quantity</label>';
echo '<input id="'.$row["id"].'" name="'.$row['id'].'" type="text" data-error=".errorTxt'.$row["id"].'"><div class="errorTxt'.$row["id"].'"></div></td></tr>';
}

Your $_GET variable should be $_GET['q'] instead of $_GET['data'], because you set the URL to test.php?q=data.
Also, you shouldn't put raw user provided data in SQL queries, use prepared statement instead, because of risks of SQL injection.

Can't get ajax working with PHP to load a table of info from MySQL

So basically I have a drop down list that displays data from a MySQL table(accounts) that would display user accounts. When the user selects one of the accounts I want it to display all facilities(facility table) that are owned by that account.
I have the drop down displaying the accounts, but it will not run the onChange() function to load my table. Here is everything I have, can someone tell me why my function is not getting triggered at all?
Index.php
<?php
require_once('sessionstart');
require_once('header.php');
require_once('dbconn.php');
//Accounts
require_once('getaccounts.php');
//Facility
echo "<div id='facilities'>";
require_once('getfacility.php');
echo "</div>";
?>
<?php
require_once 'footer.php';
?>
getaccounts.php
<?php
//require files
require_once('sessionstart.php');
require_once('dbconn.php');
//clear options variable
$options = "";
//connect to db and test connection.
$dbc = mysqli_connect(DB_HOST, DB_USER, DB_PASSWORD, DB_NAME);
if (!$dbc) {
die("Connection failed: " . mysqli_connect_error());
}
$sql = "SELECT account_id, account_name FROM accounts";
$data = mysqli_query($dbc, $sql);
//loop through data and display all accounts
while ($row = mysqli_fetch_array($data)) {
$options .="<option>" . $row['account_name'] . "</option>";
}
//account drop down form
$accountDropDown="<form id='account' name='account' method='post' action='getaccounts.php'>
<label>Accounts: </label>
<select name='account' id='account' onchange='showFacilities(this.value)'>
<option selected='selected' disabled='disabled' value=''>Select account</option>
" . $options . "
</select>
</form>";
//echo out account form
echo $accountDropDown;
?>
This works how I need it to and displays all accounts within the drop down. However I can't seem to get the showFacilities() function to work.
getfacility.php
<?php
require_once('dbconn.php');
$q = intval($_GET['q']);
$dbc = mysqli_connect(DB_HOST, DB_USER, DB_PASSWORD, DB_NAME);
if (!$dbc) {
die("Connection failed: " . mysqli_connect_error());
}
$sql = "SELECT * FROM facility "
. "INNER JOIN accounts ON accounts.account_id = facility.account_id "
. "WHERE facility.account_id = '".$q."'";
$data = mysqli_query($dbc, $sql);
echo "<table>
<tr>
<th>Facility Number</th>
<th>Facility Name</th>
<th>Facility Address</th>
<th>Facility City</th>
</tr>";
//loop through data and display all accounts
while ($row = mysqli_fetch_array($data)) {
echo "<tr>";
echo "<td>" . $row['facility_number'] . "</td>";
echo "<td>" . $row['facility_name'] . "</td>";
echo "<td>" . $row['facility_address'] . "</td>";
echo "<td>" . $row['facility_city'] . "</td>";
echo "</tr>";
}
echo "</table>";
?>
footer.php (includes showFacilities())
<script>
function showFacilities(account){
//I wrote this to test and see if this function was even being triggered.
document.alert("test");
if(account == ""){
return;
}
if (window.XMLHttpRequest) {
// code for IE7+, Firefox, Chrome, Opera, Safari
xmlhttp = new XMLHttpRequest();
} else {
// code for IE6, IE5
xmlhttp = new ActiveXObject("Microsoft.XMLHTTP");
}
xmlhttp.onreadystatechange = function() {
if (xmlhttp.readyState == 4 && xmlhttp.status == 200) {
document.getElementById("facilities").innerHTML = xmlhttp.responseText;
}
}
else{
xmlhttp.open("GET","getfacility.php?q="+account,true);
xmlhttp.send();
}
}
</script>
<footer>
<p>Copyright &copy</p>
</footer>
</body>
</html>
Please tell me if I am doing this all wrong, am I laying everything out properly? Why is this function not being hit?
I have tried to a bunch of different things, and I just can't seem to get this to work, any help or advice or even a push in the proper direction will be very appreciated, thanks.

Your if else clauses don't add up (so your script is generating a script error, most likely a syntax error).
else{
xmlhttp.open("GET","getfacility.php?q="+account,true);
xmlhttp.send();
}
This piece doesn't have an IF to accompany it.
This would be correct:
if(account == ""){
return;
}
else {
if (window.XMLHttpRequest) {
// code for IE7+, Firefox, Chrome, Opera, Safari
xmlhttp = new XMLHttpRequest();
} else {
// code for IE6, IE5
xmlhttp = new ActiveXObject("Microsoft.XMLHTTP");
}
xmlhttp.onreadystatechange = function() {
if (xmlhttp.readyState == 4 && xmlhttp.status == 200) {
document.getElementById("facilities").innerHTML = xmlhttp.responseText;
}
}
xmlhttp.open("GET","getfacility.php?q="+account,true);
xmlhttp.send();
}
On a sidenote: Why create a form wrapper around your select (the one that where you can load accounts) when you use an onchange event to fire an XmlHTTPRequest?

How to properly load one ajax request after another

I am creating a messaging system for a website that I am making. Basically, it consists of clicking one button and two Ajax Requests afterwards. I am not even sure I am going about this the right way. On click of the button the first Ajax starts to call. The first ajax request loads a file that loads the style of the messages and retrieves them from a database. The problem I am having is that the first request sometimes takes to long to finish and the other request does not get complete. Another problem I am having is that if I put an "animation delay" type thing on it then it will look like the page it running slow. You can run an example at "http://www.linkmesocial.com/linkme.php?activeTab=mes" you must type or copy and past the whole length for it to work otherwise you will redirect to the login page. Any advice would be AWESOME! If there is some easier way to set up a messaging system please feel free to give me some advice or direct me to a tutorial. THANK YOU SO MUCH!
I would also like the know if this is a good practice. Please :)
My Original file. On click of class "mes_tab" a form is submitted. also the function mes_main() is called.
session_start();
$username = $_SESSION['user'];
$messages = mysqli_query($con, "SELECT * FROM messages WHERE recipient='$username'");
echo "<div id=\"mes_main-bar_top\" class=\"center\">Messages</div>";
echo "<div id=\"mes_main\">";
echo "<table id=\"mes_main-allView\" class=\"left\">";
echo "<td class=\"mes_tab-change\" >^</td>";
$from=array("","","", "", "", "", "", "");
for ($msgCount = 0; $msgCount < 8; $msgCount++){
$row = mysqli_fetch_array($messages);
$from[$msgCount] = $row['sender'];
for ($prev = 0; $prev < $msgCount; $prev++)
{
if ($from[$msgCount] == $from[$prev] )
{
$cont = true;
break;
}
}
if ($cont)
{
$cont = false;
continue;
}
if ($row['message'] == ""){
break;
}
echo "<tr><td class=\"mes_tab\" onclick=\"mes_main('" . $row['sender'] . "')\">";
echo "<h3 class=\"center\">" . $row['sender'] . "</h3>";
echo "<form id=\"" . $row['sender'] . "\" >";
echo "<input name=\"sender\" value=\"" . $row['sender'] . "\" hidden/>";
echo "<input name=\"id\" value=\"" . $row['id'] . "\" hidden/>";
echo "</form>";
echo "</td></tr>";
}
if ($msgCount == 8)
{
echo "<td id=\"mes_tab-change_bottom\" class=\"mes_tab-change\">V</td>";
}
echo "</table> <!-- end mes_main-allView -->";
echo "<div id=\"mes_main-mesView\" class=\"right\">";
echo "</div> <!-- end mes_main-mesView -->";
echo "</div> <!-- end mes_main -->";
mes_main() function from above. The two ajax functions inside are what I am referring to in the post above.
function mes_main(x)
{
var sender = x;
$( sender ).submit(function( event ) {
event.preventDefault();
});
ajax_req_mes("scripts/home/php/mes_load.php?" + sender , "mes_main-mesView");
ajax_req_mes("scripts/home/php/mes_content.php?" + sender ,"mes_content");
}
mes_load.php
the $sender var is created by passing the sender username through the URL. That is why I do php explode on the url.
session_start();
$username = $_SESSION['user'];
$url = "http://$_SERVER[HTTP_HOST]$_SERVER[REQUEST_URI]";
$sender = explode('?', $url);
$recieved = mysqli_query($con, "SELECT * FROM messages WHERE recipient='$username' AND sender='$sender[1]'");
$sent = mysqli_query($con, "SELECT * FROM messages WHERE recipient='$sender[1]' AND sender='$username'");
echo "<div id=\"mes_content\"></div>";
echo "<div id=\"mes_field\" class=\"right\"></div>";
mes_content.php
session_start();
$username = $_SESSION['user'];
$url = "http://$_SERVER[HTTP_HOST]$_SERVER[REQUEST_URI]";
$sender = explode('?', $url);
$recieved = mysqli_query($con, "SELECT * FROM messages WHERE recipient='$username' AND sender='$sender[1]'");
$sent = mysqli_query($con, "SELECT * FROM messages WHERE recipient='$sender[1]' AND sender='$username'");
echo "<table id=\"mesView-table\">";
$REC = array();
$SENT = array();
$ID = array();
for ($i = 0; $i < 25; $i++)
{
$rec = mysqli_fetch_array($recieved);
$sent = mysqli_fetch_array($sent);
if ($rec['id'] > 0)
{
$REC[$i] = $rec['id'];
}
if ($sent['id'] > 0)
{
$SENT[$i] = $sent['id'];
}
}
$ID = array_merge($SENT, $REC);
sort($ID);
for ($x = 0; $x < count($ID); $x++)
{
$key = $ID[$x];
$result = mysqli_query($con, "SELECT * FROM messages WHERE id = '$key'");
$res = mysqli_fetch_array($result);
if (in_array($key, $REC))
{
echo "<tr><td class='mes_recieved'>";
echo $res['message'];
echo "</tr></td>";
}
elseif (in_array($key, $SENT))
{
echo "<tr><td class='mes_sent'>";
echo $res['message'];
echo "</tr></td>";
}
}
echo "</table>";

Set async to false in your ajax requests!That's how the second one will wait for completing the first one and then start.
Also you can catch the on success and on error for the purposes you have.

Just use the "success" and "error" callbacks.
Also you could use the "done" callback
But, IMO, for that kind of problem I think a better alternative would be using Websockets
EDIT:
Here is some example of how you could do it:
jQuery.ajax({
type : "POST",
data : {msg:"your message"}
url : "http://fu.com/myfile.php",
success: function(response){
//Do something with your response
}
}).done(secondCall());
function secondCall(){
jQuery.ajax({
type : "POST",
data : {data:"data"}
url : "http://fu.com/myfile.php",
success: function(response){
//Do something with your response
}
});
}
EDIT2:
For visibility, here is a tutorial using websockets: http://www.sanwebe.com/2013/05/chat-using-websocket-php-socket

Fetch multiple data from a php file using AJAX and insert them in different input fields

I am using AJAX in order to access data from a php file.
I have problem with the format of retrieved data from database, please help.
So, this is my ajax function splice. It retrieves data from find_account.php
function processReqChange() {
// only if req shows "loaded"
if (req.readyState == 4) {
// only if "OK"
if (req.status == 200) {
form_prof.prof_id.value = req.responseText;
form_prof.prof_name.value = req.responseText;
form_prof.prof_username.value = req.responseText;
form_prof.prof_password.value = req.responseText;
}
else {
alert("Problem in retrieving the XML data:\n" + req.statusText);
}
}
}
find_account.php
<?php
include("connect.php");
session_start();
$account = $_GET['account'];
$query = "SELECT * FROM profs WHERE profs_name = '".$account."'";
$result = mysql_query($query);
$num = mysql_num_rows($result);
if(empty($num))
{
echo 'DATA NOT FOUND';
}
else
{
$arr = mysql_fetch_array($result);
$id = $arr['profs_number'];
$name = $arr['profs_name'];
$username = $arr['profs_username'];
$password = $arr['profs_password'];
}
header("Content-type: text/plain");
echo $id;
echo $name;
echo $username;
echo $password;
?>
and I have 4 input boxes in my HTML from where the req.responseText puts the value
and everytime I search the name in the input field for example:
Search: [ Dorothy Perkins ]
The output goes like [id,name,username,password]:
[20111Dorothy Perkinsdperkins#mail.com123456] [same with 1st field] [same] [same]
Wherein I want it to be like...
[20111] [Dorothy Pekins] [dperkins#mail.com] [123456]
Where [ ] are input fields.
Please help me arrange my format, I am so confused. I am new to this.

You can encode return values in json before sending back.
In PHP
<?php
include("connect.php");
session_start();
$account = $_GET['account'];
$query = "SELECT * FROM profs WHERE profs_name = '".$account."'";
$result = mysql_query($query);
$num = mysql_num_rows($result);
if(empty($num))
{
$returnValues = 'DATA NOT FOUND';
}
else
{
$arr = mysql_fetch_array($result);
$returnValues = json_encode($arr);
}
echo $returnValues;
?>
In Javascript
function processReqChange() {
// only if req shows "loaded"
if (req.readyState == 4) {
// only if "OK"
if (req.status == 200) {
req = JSON.parse(reg);
form_prof.prof_id.value = req.id;
form_prof.prof_name.value = req.name;
form_prof.prof_username.value = req.username;
form_prof.prof_password.value = req.password;
}
else {
alert("Problem in retrieving the XML data:\n" + req.statusText);
}
}
}

You have to write the data in some format from your PHP code (XML, json, or simply separate the values with a comma), and parse it from your javascript.
For example, in PHP:
echo $id . "," . $name . "," . $username . "," . $password;
And then in the javascript:
values = req.responseText.split(",");
form_prof.prof_id.value = values[0]
form_prof.prof_name.value = values[1];
form_prof.prof_username.value = values[2];
form_prof.prof_password.value = values[3];
Of course you may have to do something more complicated if the values may contain a comma.

You can try this
$account = $_GET['account'];
$query = "SELECT * FROM profs WHERE profs_name = '".$account."'";
$result = mysql_query($query, MYSQLI_STORE_RESULT);
while($arr = $result->fetch_array(MYSQLI_ASSOC)) {
$returnValues = json_encode($arr);
break;
}
echo $returnValues;
Note that column names are used as associative index for $arr
Hope it works.