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A part of AJAX response storing in PHP variable

I need to store a piece of data, into PHP variable, which is received through AJAX response in an input box. How can I do this?
<script type="text/javascript">
$(document).ready(function() {
$("#user_id").change(function() {
var id = $(this).val();
var dataString = 'user_id='+ id;
$.ajax({
type: "POST",
url: "wmat_details.php",
data: dataString,
cache: false,
success: function(result) {
var data = result.split(",");
$('#name').val(data[0]);
$('#email').val(data[1]);
$('#ref_id').val(data[2]);
$('#candidature_start').val(data[3]);
$('#candidature_end').val(data[4]);
$('#default_attempts').val(data[5]);
$('#existing_complimentary').val(data[6]);
$('#wmat_start').val(data[9]);
$('#wmat_end').val(data[10]);
$('#attempts_taken').val(data[11]);
}
});
});
});
</script>
As shown in above code, I want to store $('#attempts_taken').val(data[11]); this value to a PHP variable. Any insight is appreciated.

Unfortunately you can't.
PHP is server side while jQuery (JS) is client side. They are two separate layers of abstraction that interact only when the client call the server.
I don't have enough informations about what you need to do with data[11] but it seems that you have only one option: make a consecutive AJAX call to the php file that will manipulate data[11].
The consecutive AJAX call must be executed from inside the first call success callback; something like this:
success: function(result){
// Your on success logic
// ...
// Prepare the object to send to the server
var objData = {};
objData.attemptsTaken = data[11];
// Execute the second AJAX call to the server
$.ajax({
type: "POST",
url: "second_call_destination_file.php",
data: objData,
success: function(result){
// Do something on success
},
error: function(){
// Do something on error
},
complete: function(){
// Do something on complete (executed after success and error)
}
}

You cannot store ajax response into a php variable.
way 1 :
You can make another ajax call.
way 2 :
you can set session.

Sending POST data to PHP script - jQuery, AJAX & PHP

I seem to be struggling with sending POST data to my PHP script.
My AJAX sends data (an ID of a blog post) to my PHP script, which then finds the row that contains a matching ID from a database.
The script then sends back the title of the blog post and the content of the post in an array, which AJAX picks up and inserts into a form in the DOM.
I can successfully:
insert sample data (for example, if I simply store strings into the array I'm passing back to AJAX, it will successfully insert those strings into the form); and
insert the correct data from the database when a static ID is specified (for example, if I switch out $_POST['editpostid'] and specify the integer 5 instead, the query successfully finds the row with ID = 5 and AJAX inserts this data into the form).
Therefore, from my point of view, the problem is that the ID is never reaching the PHP script, or my script cannot see the ID inside the JSON object.
Please take a look at my code and let me know what you think. I'm new to all this, so I'd appreciate your feedback - if it fixes the problem or not.
Javascript/jQuery:
// When edit button is clicked
$('li.edit').click(function() {
// Get class (postid inserted with PHP) of edit button, excluding edit class
var oldpostid = $(this).attr('class').split(' ')[1];
alert(oldpostid); // Returns the correct postid, for example 5
var jsonObj = { 'postid': oldpostid };
alert(jsonObj); // Returns 'object Object'
// Send postid to PHP script
$.ajax({
type: 'POST',
url: '../scripts/fetchpost.php',
dataType: 'json',
data: { 'editpostid': jsonObj },
success: function() {
// Fetch post data back from script
$.getJSON('../scripts/fetchpost.php', function(data) {
alert(data.title); // Returns null
alert(data.content); // Returns null
// All of the below code works if the PHP script returns sample text,
// or if an ID is specified in the PHP script itself
var title = data.title;
var content = data.content;
// Insert data into editor
$('#titlehead').text(title);
$('#edittitle').val(title);
var editor = 'editpost-content';
tinymce.get(editor).setContent(content);
});
},
error: function( e ) {
console.log(e.message);
}
});
});
PHP:
<?php
// Specifies connection details
include('../scripts/config.php');
// Fetch data from AJAX
$postid = $_POST['editpostid']; // Where I think the problem lies. Returns null.
// Again, this works if I switch out $_POST with an integer, such as 5
// Find rows in database that match postid
$postedit_qry = mysqli_query( $dbconnect, "SELECT * FROM posts WHERE postid='$postid'" );
// Store results in an associative array
$row = mysqli_fetch_assoc( $postedit_qry );
// Split array into variables
$title = $row['title'];
$content = $row['content'];
// Organise data into an array for json
$postedit = array(
'title' => $title,
'content' => $content
);
// Return array as json object for ajax to pick up
echo json_encode( $postedit );
// Close connection
mysqli_close( $dbconnect );
?>
Update - Solution:
Fixed jQuery/Javascript:
// Snip
// Get class (postid inserted with PHP) of edit button, excluding edit class
var oldpostid = $(this).attr('class').split(' ')[1];
// Send postid to PHP script
$.ajax({
type: 'POST',
url: '../scripts/fetchpost.php',
dataType: 'json',
contentType: 'application/x-www-form-urlencoded',
data: { "editpostid": oldpostid },
success: function(data) {
var title = data.title;
var content = data.content;
// Snip
The PHP script remains the same.
Many thanks for your help!
MrPupper

I think you missed the index 'postid' and need to replace this
$postid = $_POST['editpostid'];
with this line :
$postid = $_POST['editpostid']['postid'];
Or instead of sending
data: { 'editpostid': jsonObj },
send this
data: { 'editpostid': oldpostid },

Looking over your code, it seems like you are getting null because you are requesting the fetchpost.php script twice. Once when you contact the script via $.ajax(...); and once more when you call $.getJSON(...);. When you contact via $.getJSON(...);, though, you are not POSTing data and it seems like your script does not have a properly defined way to handle GET requests, so the script doesn't know how to react and it returns null information.
I would change the JavaScript/jQuery to the following:
// When edit button is clicked
$('li.edit').click(function() {
// Get class (postid inserted with PHP) of edit button, excluding edit class
var oldpostid = $(this).attr('class').split(' ')[1];
alert(oldpostid); // Returns the correct postid, for example 5
var jsonObj = { 'postid': oldpostid };
alert(jsonObj); // Returns 'object Object'
// Send postid to PHP script
$.ajax({
type: 'POST',
url: '../scripts/fetchpost.php',
dataType: 'json',
data: {'editpostid': jsonObj },
success: function(sData) {
var data = JSON.parse(sData);
alert(data.title); // Returns null
alert(data.content); // Returns null
// All of the below code works if the PHP script returns sample text,
// or if an ID is specified in the PHP script itself
var title = data.title;
var content = data.content;
// Insert data into editor
$('#titlehead').text(title);
$('#edittitle').val(title);
var editor = 'editpost-content';
tinymce.get(editor).setContent(content);
},
error: function( e ) {
console.log(e.message);
}
});
});
Additionally, PHP is going to be expecting an application/x-www-form-urlencoded value to be able to interact with $_POST[...]. As such, if you want to feed it JSON, then in your PHP, you will need to implement a solution such as: $postedData = json_decode(file_get_contents('php://input')); (See more about that in this answer; for more about json_decode, see the official PHP documentation for json_decode.)
Note: While outside of the scope of your question, and you may know this already, I find it important to point out that your MySQL is insecure and vulnerable to SQL injection due to just blindly trusting that the postId has not been tampered with. You need to sanitize it by saying $postid = $dbconnect->real_escape_string($postid); after you initialize $dbconnect and connect to the database, but before you put the $postid into your SQL query string.

Issues passing form data to PHP using Ajax

I originally had a regular HTML form that submitted the data entered through a button, which redirected the user to the PHP code page ran the code and everything worked.
Since everything now is confirmed working I need to pass the variables in the form to PHP using Ajax instead to keep the user on the original page.
All of my code checks out everywhere except for any Ajax request I use in the below function. The function correctly grabs all the variables from the form but no matter what form of Ajax or $.post that I use it fails to pass anything.
I am trying to pass all data to http://localhost/send-email.php and respond to the user with a pop up including the echo response from the PHP code.
src="https://ajax.googleapis.com/ajax/libs/jquery/3.1.1/jquery.min.js"
function capacity(){
var fullname = document.getElementById("fullname").value;
var time = document.getElementById("time").value;
var aux = document.getElementById("aux").value;
var issue = document.getElementById("issue").value;
var issueid = document.getElementById("issueid").value;
var reason = document.getElementById("reason").value;
}
Like I said I read all documentation on Ajax and followed many examples on here but i could not get anything to work. Any help on what my Ajax call should look like is appreciated.

There are a couple of different ways you can POST in the backend.
Method 1 (POST Serialize Array from Form) -
jQuery.post()
$.post('/send-email.php', $('form').serializeArray(), function(response) {
alert(response);
});
Method 2 (Structure Object and POST Object) -
jQuery.post()
var formObject = {
fullname: $('#fullname').val(),
time: $('#time').val(),
aux: $('#aux').val(),
issue: $('#issue').val(),
issueid: $('#issueid').val(),
reason: $('#reason').val()
};
$.post('/send-email.php', formObject, function(response) {
alert(response);
});
Method 3 (Use AJAX to POST Serialize Array from Form) -
jQuery.ajax()
$.ajax({
method: 'POST',
url: '/send-email.php',
data: $('form').serializeArray(),
}).done(function(response) {
alert(response);
});
Method 4 (Use AJAX to POST Form Data) -
jQuery.ajax() - FormData Objects
var formData = new FormData();
formData.append('fullname', $('#fullname').val());
formData.append('time', $('#time').val());
formData.append('aux', $('#aux').val());
formData.append('issue', $('#issue').val());
formData.append('issueid', $('#issueid').val());
formData.append('reason', $('#reason').val());
$.ajax({
url: '/send-email.php',
dataType: 'json',
contentType: false,
processData: false,
data: formData,
type: 'POST',
success: function(response) {
alert(response);
}
});
Virtually, there are many different methods to achieving what you are attempting.

Setting string in javascript function in ASP.NET MVC give NullReferenceException

Inside my MVC view I have javascript that is executed by a button click. I'm trying to set a string to a random set of characters which I can get to work fine but when I try and set that string to 'randomchars' string inside the javascript I get a NullReferenceException when I try and run the view.
Below is the code snippet, the CreateRString is where the model parameter (RString) is set to the random string.
<script type="text/javascript">
function showAndroidToast(toast) {
var url = '#Url.Action("CreateRString", "Functions")';
$.ajax({ url: url, success: function (response) { window.location.href = response.Url; }, type: 'POST', dataType: 'json' });
var randomchars = '#(Model.RString)';
}
</script>
Is the syntax correct? I'm not too sure why it's getting the NULL.

The javascript is executed after the page been delivered to the client (i.e. web browser). Your razor code here is executed on the server before the page is sent to the client. Therefore, the ajax method will execute after you try to access Model.RString
To fix this you can either call CreateRString on the server, or you can set randomchars by using the response in the success callback.
To explain option 2 a bit further. You could do something like this:
//Action Method that returns data which includes your random chars
public JsonResult CreateRString()
{
var myRandomChars = "ABCDEF";
return new JsonResult() { Data = new { RandomChars = myRandomChars } };
}
//The ajax request will receive json created in the CreateRString method which
//contains the RandomChars
$.ajax({ url: url, success: function (response) {
var randomchars = response.Data.RandomChars;
window.location.href = response.Url;
}, type: 'POST', dataType: 'json' });
More specifically, the razor calls #Url.Action("CreateRString", "Functions") and #(Model.RString) execute first on the server.
Then showAndroidToast executes in the client's browser when you call it.

Passing a javascript array to a php page using post method

I want to pass a javascript array to a php page using ajax POST request .How to achieve this.please help..Thanks in advance

Have a look into JSON encoding.
In PHP you can decode it using json_decode, not quite sure how you'll encode it in Javascript but it is possible
http://en.wikipedia.org/wiki/JSON

using jQuery
$.post("test.php", { 'choices[]': ["Jon", "Susan"] });
Edit
if you are creating ajax object and using it then I'll suggest to convert your data in query string send it through ajax object.
like :
var userdetails = [1,2,3,4];
var queryString = "";
for(i=0; i<userdetails.length; i++){
queryString = queryString + 'userdetails[]='+userdetails[i]+'&';
}
connect.send(queryString)

example posting with json
var array = [1,2,3,4,5,6];
$.ajax({
url: "mydomain.com/url",
type: "POST",
dataType: "json",
data: {arrayName: array},
complete: function() {
//called when complete
},
success: function() {
//called when successful
},
error: function() {
//called when there is an error
},
});
Then the json could be parsed server side.
arrays can also be sent using application/x-www-form-urlencoded - this is the default format for submitting.