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Assigning javascript variable to java variable

I know I can't use javascript variable inside java code so can anyone explain me what I can do instead?
function init(srcc) {
<%if (session.getAttribute("status") != null && session.getAttribute("status").equals("member")) {%>
alert(srcc + " ");
<%application.setAttribute(session.getAttribute("currentuser"), srcc);%>
<%}%>
in this line:
<%application.setAttribute(session.getAttribute("currentuser"), srcc);%>
I can't read the srcc variable as it's assigned in javascript, this function called when I press a button in jquery, code:
var $lightbox = $("<div class='lightbox'></div>");
var $img = $("<img>");
var $caption = $("<p class='caption'></p>");
var $btn = $("<div align='center'> <INPUT TYPE='BUTTON' VALUE='Add to cart'></div>");
$lightbox.append($img).append($caption).append($btn);
$('body').append($lightbox);
$('.gallery li').click(function(e) {
e.preventDefault();
var src = $(this).children('img').attr("src");
var cap = $(this).children('img').attr("alt");
$btn.off('click').on('click', function(da) {
$(document).ready(function() {
init(src);
});
});
$img.attr('src', src);
$caption.text(cap);
$lightbox.fadeIn('fast');
$lightbox.click(function() {
$lightbox.fadeOut('fast');
});
});
I use it in an "add to cart" button, I want the server to keep data of whom added it to the cart and what he added. (srcc equals what he added and session.getAttribute("currentuser") is whom added).
Thanks guys.

You can send that JavaScript variable to Java using an AJAX request
You would have to have a serverside route set up to handle this request coming in and process the sent data.
Since I already see jQuery being used in your code, I'll use this AJAX function in my example code. You can send an HTTP request without your browser reloading the page in this way:
$.get("/urlOfCartHandler/?parameterName=" + javaScriptVariableContainingDataYouWantToSend, function(data) {
//Request was a success
}).fail(function() {
//Request failed
});

Send a string from javascript to php (in the same file)

So basically, I got a php file where I create a script in the header.
In this script, I take the value of two textbox with document.getElementByID and I concatenate them in a variable. But now, in the same script, I want to send that var to a php section to use it.
I tried the ajax way, but since the php and the javascript is in the same file, it make an error.
Here is what the script section looks like :
IN FILE.PHP
<script type="text/javascript">
rowNum = 0;
function some_function()
{
var command = "somebasiccommand";
if(document.getElementById("text_1").value != "" && document.getElementById("text_2").value != "")
{
command += " " + document.getElementById("text_1").value + " " + document.getElementById("text_2").value;
}
<?php
$parameter = command; <----- obviously not working, but that's basically what im looking for
$output = exec("someExecutable.exe $parameter");
(...)
?>
}
</script>
EDIT 1
So here it is, I tried to use ajax this time, but this isn't working, seems like i miss something. Here is the server.php:
<?php
$parameter = $_POST['command'];
$output = exec("someexecutable.exe $parameter");
$output_array = preg_split("/[\n]+/", $output);
print_r($parameter);
?>
And here is my ajax call in my client.php (in a js script):
var command = "find";
if(document.getElementById("text_1").value != "" && document.getElementById("text_2").value != "")
{
command += " " + document.getElementById("text_1").value + " " + document.getElementById("text_2").value;
}
var ajax = new XMLHttpRequest;
ajax.open("POST", "server.php", true);
ajax.send(command);
var output_array = ajax.responseText;
alert(output_array);
For some reason, it doesn't go farther then the ajax.open step. On the debugger console of IE10, i got this error : SCRIPT438: Object doesn't support property or method 'open' .

You are trying to run a serverside script in your ClientSide script,
that's never going to work.
https://softwareengineering.stackexchange.com/questions/171203/what-are-the-differences-between-server-side-and-client-side-programming
If you want to do something with the data from text_1 and text_2, you should create a php file that can handle a post/get request via AJAX or a simple submit, featuring the data from those elements, and make it return or do whatever it is you want it to end up doing.

You can't use javascript variable (client) from php (server). To do that, you must call ajax.
<script type="text/javascript">
rowNum = 0;
function some_function()
{
var command = "somebasiccommand";
if(document.getElementById("text_1").value != "" && document.getElementById("text_2").value != "")
{
command += " " + document.getElementById("text_1").value + " " + document.getElementById("text_2").value;
}
//AJAX call to a php file on server
//below is example
var ajax = window.XMLHttpRequest;
ajax.open("POST", "yourhost.com/execute.php", true);
ajax.send(command);
}
</script>
And this is execute.php on server
<?php
$parameter = $_POST['command'];
$output = exec("someExecutable.exe $parameter");
(...)
?>

Alright... I pretty much changed and tested many things and I found out that the problem was the async property of the .send command. I was checking the value of the respondText too fast. Putting the third property of .open to false made the communication sync, so I receive the infos properly. I got another problem right now, but its not the same thing, so I will do another post.

how to send javascript variable to php mysql [duplicate]

This question already has answers here:
What is the difference between client-side and server-side programming?
(3 answers)
Closed 7 years ago.
I am trying to insert javascript varaible to php mysql, but it is not inserting. it is inserting as <javascript>document.write(window.outerWidth); </javascript> x <javascript>document.write(window.outerHeight); </javascript>. but the result is 1366 x 728
What should I do?
<?php
$width = " <script>document.write(window.outerWidth); </script>";
$height = " <script>document.write(window.outerHeight); </script>";
$xex = " x ";
$resulteee = "$width $xex $height";
echo $resulteee;
?>

AJAX is a good solution to your problem :
<script type="text/javascript">
function call_ajax () {
var width = window.outerWidth;
var height = window.outerHeight;
var xmlhttp = new XMLHttpRequest();
xmlhttp.onreadystatechange = function() {
if (xmlhttp.readyState == 4 && xmlhttp.status == 200) {
document.getElementById("abc").innerHTML = xmlhttp.responseText;
}
}
xmlhttp.open("POST", "a.php?height="+height+"width="+width, true);
xmlhttp.send();
}
</script>
and on the page a.php, you can echo your variables to get the output like this :
<?php
echo $_POST['height'];
echo $_POST['width'];
die;

The best way is AJAX, which is a way for Javascript to send data to a PHP script. You should do some research on your own, but your solution will end up looking something like this. I'm using jQuery syntax, which is a really helpful Javascript library that I recommend looking into.
// get values we want
var width = window.outerWidth;
var height = window.outerHeight;
var payload = {"width" : width, "height" : height}; // just a normal object
// send them to server
$.get('/path/to/script.php', payload, function(response) {
alert('Sent the values!');
});
And in your PHP:
<?php
$width = $_GET['width'];
$height = $_GET['height];
/*
* DEFINITELY sanitize these things before they're anywhere NEAR the database!
* research "prepared statements" and "mysqli escape" or you are going to have a very bad time with a hacked server
*/
// do some database stuff!
Hopefully this gives you a good starting point. You really need to make sure you sanitize data before you blindly let it touch a database query or attackers can easily perform a SQL Injection attack, deleting your database or dumping all your data. These are very bad things.

You'll have to send it to a separate php file to insert it into MySQL... You'll also have to use Ajax. Include the jquery plugin in your page for that.
So this would include this in your main page. Call the submitstuff() function when the button is pushed instead of submitting a form like normal:
<script>
function submitstuff(){
var wheight = window.outerHeight;
var wwidth = window.outerWidth;
var results = wwidth+" x "+wheight;
$.ajax({
url : "submit.php",
type: "POST",
data : "result="+results,
});
}
</script>
Then, make a file called submit.php and put it in the same folder as your main file.
submit.php
/* include all your database connection stuff */
mysql_query("insert into `yourtable` (`size`) values ('".$_POST['result']."');");
I didn't test this, but I think it might work... :)

Try jQuery's $.post
var width = x;
var height = y;
$.post( "page.php", // name of the page you want to send the variables
{width:width,height:height}, // variables
function( data ) { // returned values from the page
alert(data);
}
);
You can get the variables using $_POST['width'] and $_POST['height'].

Passing a JavaScript value to PHP on completion of quiz

I have a web page that allows users to complete quizzes. These quizzes use JavaScript to populate original questions each time it is run.
Disclaimer: JS Noob alert.
After the questions are completed, the user is given a final score via this function:
function CheckFinished(){
var FB = '';
var AllDone = true;
for (var QNum=0; QNum<State.length; QNum++){
if (State[QNum] != null){
if (State[QNum][0] < 0){
AllDone = false;
}
}
}
if (AllDone == true){
//Report final score and submit if necessary
NewScore();
CalculateOverallScore();
CalculateGrade();
FB = YourScoreIs + ' ' + RealScore + '%. (' + Grade + ')';
if (ShowCorrectFirstTime == true){
var CFT = 0;
for (QNum=0; QNum<State.length; QNum++){
if (State[QNum] != null){
if (State[QNum][0] >= 1){
CFT++;
}
}
}
FB += '<br />' + CorrectFirstTime + ' ' + CFT + '/' + QsToShow;
}
All the Javascript here is pre-coded so I am trying my best to hack it. I am however struggling to work out how to pass the variable RealScore to a MySql database via PHP.
There are similar questions here on stackoverflow but none seem to help me.
By the looks of it AJAX seems to hold the answer, but how do I implement this into my JS code?
RealScore is only given a value after the quiz is complete, so my question is how do I go about posting this value to php, and beyond to update a field for a particular user in my database on completion of the quiz?
Thank you in advance for any help, and if you require any more info just let me know!

Storing data using AJAX (without JQuery)
What you are trying to do can pose a series of security vulnerabilities, it is important that you research ways to control and catch these if you care about your web application's security. These security flaws are outside the scope of this tutorial.
Requirements:
You will need your MySQL database table to have the fields "username" and "score"
What we are doing is writing two scripts, one in PHP and one in JavaScript (JS). The JS script will define a function that you can use to call the PHP script dynamically, and then react according to it's response.
The PHP script simply attempts to insert data into the database via $_POST.
To send the data to the database via AJAX, you need to call the Ajax() function, and the following is the usage of the funciton:
// JavaScript variable declarations
myUsername = "ReeceComo123";
myScriptLocation = "scripts/ajax.php";
myOutputLocation = getElementById("htmlObject");
// Call the function
Ajax(myOutputLocation, myScriptLocation, myUsername, RealScore);
So, without further ado...
JavaScript file:
/**
* outputLocation - any HTML object that can hold innerHTML (span, div, p)
* PHPScript - the URL of the PHP Ajax script
* username & score - the respective variables
*/
function Ajax(outputLocation, PHPScript, username, score) {
// Define AJAX Request
var ajaxReq = new XMLHttpRequest();
// Define how AJAX handles the response
ajaxReq.onreadystatechange=function(){
if (ajaxReq.readyState==4 && xml.status==200) {
// Send the response to the object outputLocation
document.getElementById(outputLocation).innerHTML = ajaxReq.responseText;
}
};
// Send Data to PHP script
ajaxReq.open("POST",PHPScript,true);
ajaxReq.setRequestHeader("Content-type","application/x-www-form-urlencoded");
ajaxReq.send("username="username);
ajaxReq.send("score="score);
}
PHP file (you will need to fill in the MYSQL login data):
<?php
// MYSQL login data
DEFINE(MYSQL_host, 'localhost');
DEFINE(MYSQL_db, 'myDatabase');
DEFINE(MYSQL_user, 'mySQLuser');
DEFINE(MYSQL_pass, 'password123');
// If data in ajax request exists
if(isset($_POST["username"]) && isset($_POST["score"])) {
// Set data
$myUsername = $_POST["username"];
$myScore = intval($_POST["score"]);
} else
// Or else kill the script
die('Invalid AJAX request.');
// Set up the MySQL connection
$con = mysqli_connect(MYSQL_host,MYSQL_user,MYSQL_pass,MYSQL_db);
// Kill the page if no connection could be made
if (!$con) die('Could not connect: ' . mysqli_error($con));
// Prepare the SQL Query
$sql_query="INSERT INTO ".TABLE_NAME." (username, score)";
$sql_query.="VALUES ($myUsername, $myScore);";
// Run the Query
if(mysqli_query($con,$sql))
echo "Score Saved!"; // Return 0 if true
else
echo "Error Saving Score!"; // Return 1 if false
mysqli_close($con);
?>

I use these function for ajax without JQuery its just a javascript function doesnt work in IE6 or below. call this function with the right parameters and it should work.
//div = the div id where feedback will be displayed via echo.
//url = the location of your php script
//score = your score.
function Ajax(div, URL, score){
var xml = new XMLHttpRequest(); //sets xmlrequest
xml.onreadystatechange=function(){
if (xml.readyState==4 && xml.status==200){
document.getElementById(div).innerHTML=xml.responseText;//sets div
}
};
xml.open("POST",URL,true); //sets php url
xml.setRequestHeader("Content-type","application/x-www-form-urlencoded");
xml.send("score="score); //sends data via post
}
//Your PHP-script needs this.
$score = $_POST["score"]; //obtains score from POST.
//save your score here
echo "score saved"; //this will be displayed in the div set for feedback.
so call the javascript function with the right inputs, a div id, the url to your php script and the score. Then it will send the data to the back end, and you can send back some feedback to the user via echo.

Call simple a Script with the parameter score.
"savescore.php?score=" + RealScore
in PHP Side you save it
$score = isset ($_GET['score']) ? (int)$_GET['score'] : 0;
$db->Query('INSERT INTO ... ' . $score . ' ...');
You could call the URL via Ajax or hidden Iframe.
Example for Ajax
var request = $.ajax({
url: "/savescore.php?score=" + RealScore,
type: "GET"
});
request.done(function(msg) {
alert("Save successfull");
});
request.fail(function(jqXHR, textStatus) {
alert("Error on Saving");
});

How do I fetch PHP script output from Javascript?

This is an example of the PHP script I want to get the output from within my javascript file:
data.php
<?php
$input = file_get_contents('data.txt');
echo $input."\n";
?>
script.js
$(document).ready(function(){
var data;
// get output from data.php
console.log( data );
});
I just want a way to test to see if the data from within the data.txt file that is being stored in a php variable can be passed into the javascript file and then printed within the javascript console on the html page.
I want to do this so that I can store a variable in the text file and then reference it as it dynamically is updated from multiple users at the same time.
I've seen ways to do this, but it involves the javascript being in the same file as the html, which is not the case here. I'm also using jquery so I don't know if that makes a difference. I've never used php before and am new to javascript, so any help would be appreciated.

You can put you php code in the javascript file if you change the extension to "php". As "php" extensions will get delivered as Html per default, you have to state that it is Javascript in the code.
script.js.php
<?php header('Content-Type: application/javascript');
?>console.log("<?php
$input = file_get_contents('data.txt');
echo $input."\n";
?>");
$(document).ready(function(){
$("#imgTag, #img2").on("click", process);
var size = 0;
function getTarget(evt)
{
evt = evt || window.event;
return evt.target || evt.scrElement;
}
var temp;
console.log("before get");
console.log("post get");
console.log(size);
function changeSize(myName, myOther)
{
var name = myName;
var other = myOther;
if($("#" + name).height() < 400)
{
$("#" + name).height($("#" + name).height() + 5);
$("#" + name).width($("#" + name).width() + 5);
$("#" + other).height($("#" + other).height() - 5);
$("#" + other).width($("#" + other).width() - 5);
}
}
function process(event)
{
var name = getTarget(event).id;
var other;
if(name == "imgTag")
{
other = "img2";
}
else
other = "imgTag";
console.log($("#" + name));
console.log("Changing size!!!");
console.log( $("#" + name).height());
changeSize(name, other);
}
});

You can read that text file directly with jquery like this:
$.ajax({
url : "data.txt",
dataType: "text",
success : function (data) {
// Display the data in console
console.log(data);
// Or append it to body
$('body').append(data);
}
});
The same way you can read output from your php file, in which case you should change the url to point to your php file. Another thing you should read about is different options of communicating server-client side like json data structure etc.
Documentation: https://api.jquery.com/jQuery.ajax/