running a php function inside javascript code [duplicate] - javascript

This question already has answers here:
What is the difference between client-side and server-side programming?
(3 answers)
Closed 9 years ago.
I hope to run a php code inside a javascript code too and I do like that :
<?php function categoryChecking(){
return false;
}?>
....
function openPlayer(songname, folder)
{
if(<?php echo categoryChecking() ?> == true)
{
if (folder != '')
{
folderURL = "/"+folder;
}else
{
folderURL = '';
}
var url = "/users/player/"+songname+folderURL;
window.open(url,'mywin','left=20,top=20,width=800,height=440');
}else{
alerte('you should click on a subcategory first');
}
}
....
<a href='javascript:void();' onClick="openPlayer('<?php echo $pendingSong['id']; ?>','')">
finally I get this error instead the alert message "you should click on a subcategory first"
ReferenceError: openPlayer is not defined
openPlayer('265','')

You're reduced your test case too far to see for sure what the problem is, but given the error message you are receiving, your immediate problem has nothing to do with PHP.
You haven't defined openPlayer in scope for the onclick attribute where you call it. Presumably, the earlier JS code is either not inside a script element at all or is wrapped inside a function which will scope it and prevent it from being a global.
Update: #h2ooooooo points out, in a comment, that your PHP is generating the JS:
if( == true)
Check your browser's error console. You need to deal with the first error messages first since they can have knock on effects. In this case the parse error in the script will cause the function to not be defined.
Once you resolve that, however, it looks like you will encounter problems with trying to write bi-directional code where some is client side and some is server side.

You cannot run PHP code from JavaScript, because PHP is a server-side language (which runs on the server) and JavaScript is a client-side language (which runs in your browser).
You need to use AJAX to send a HTTP request to the PHP page, and then your PHP page should give a response. The easiest way to send a HTTP request using AJAX, is using the jQuery ajax() method.
Create a PHP file ajax.php, and put this code in it:
<?php
$value = false; // perform category check
echo $value ? 'true' : 'false';
?>
Then, at your JavaScript code, you should first add a reference to jQuery:
<script type="text/javascript" src="jquery.js"></script>
Then, use this AJAX code to get the value of the bool:
<script type="text/javascript">
$.ajax('ajax.php')
.done(function(data) {
var boolValue = data == 'true'; // converts the string to a bool
})
.fail(function() {
// failed
});
</script>
So, your code should look like this:
function openPlayer(songname, folder) {
$.ajax('ajax.php')
.done(function (data) {
var boolValue = data == 'true'; // converts the string to a bool
if (boolValue) {
if (folder != '') {
folderURL = "/" + folder;
} else {
folderURL = '';
}
var url = "/users/player/" + songname + folderURL;
window.open(url, 'mywin', 'left=20,top=20,width=800,height=440');
} else {
alert('you should click on a subcategory first');
}
})
.fail(function () {
// failed
});
}

Related

Passing Javascript variable to php on the same page

I'm trying to pass a javascript variable to php on the same page. I tried some code but nothing worked.
The current code looks like this:
function init(e){
$('#DeleteDaily').click(function() {
d = document.getElementById("DailyRequestsList");
selected = d.selectedIndex;
var xhttp = new XMLHttpRequest();
xhttp.open("GET", "index.php?i=" + selected, true);
xhttp.send();
});
}
$(document).ready(init);
$(document).ready(function() {
$('#myForm').ajaxForm(function() {
<?php
if(isset($_POST['DeleteDaily'])) {
$Index = $_GET['i'];
}
?>
});
});
If I try to use Index as an argument for a python script it should delete an entry in a textfile and an element from a select object should be deleted on the website which doesn't happen. The python script itself works fine.
But I don't know why the variable isn't passed to php.
You can't just "mix" javascript and PHP like you're doing.
If that is inside a web page, the PHP code will be rendered (in your case, it will return nothing), and the page will just interpret an empty javascript function.
You need that PHP to be on the server, or turn it into javascript...
you can done it by
PHP Code
<?php
if(isset($_POST['DeleteDaily'])) {
$Index = $_GET['i'];
}else{
$Index='';
}
?>
Javascript code
$(document).ready(function() {
$('#myForm').ajaxForm(function() {
var index = '<?php echo $Index;?>';
if(index == ''){
//put your code
}else{
//put your code
}
});
});

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.

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");
});

Why the success alert message is appearing many times in an AJAX call made to a PHP script in following scenario?

Following are two code blocks, each one is responsible for AJAX call to a PHP file onclick of respective hyperlink:
<script language="javascript" type="text/javascript">
$(".fixed").click(function(e) {
var action_url1 = $(this).attr('delhref');
var qid = $(this).data('q_id');
$(".fixed").colorbox({inline:true, width:666});
$("#fixedPop_url").click(function(event) {
event.preventDefault();
$.get(action_url1, function(data) {
alert("Question status updated successfully");
$("#fix_"+qid).hide();
$("#notfix_"+qid).show();
});
});
$(".c-btn").bind('click', function(){
$.colorbox.close();
});
});
$(".notfixed").click(function(e) {
var action_url2 = $(this).attr('delhref');
var qid = $(this).data('q_id');
$(".notfixed").colorbox({inline:true, width:666});
$("#notfixedPop_url").click(function(event) {
event.preventDefault();
$.get(action_url2, function(data) {
alert("Question status updated successfully");
$("#notfix_"+qid).hide();
$("#fix_"+qid).show();
});
});
$(".c-btn").bind('click', function(){
$.colorbox.close();
});
});
</script>
Now the PHP code snippet from a file is written below to which the AJAX request is made. Actually, the PHP file name to which the AJAX request is going and the parameters passed required are contained in variables action_url1 and action_url1. These are working fine. Until now there is no issue for me. Also the PHP code is working fine.
<?php
$objQuestionIssue = new QuestionIssue;
$op = $_GET['op'];
switch( $op ) {
case "fixed":
$que_issue_data = $objQuestionIssue->UpdateQuestionIssueStatus($question_id, $op);
die();
break;
case "notfixed":
$que_issue_data = $objQuestionIssue->UpdateQuestionIssueStatus($question_id, $op);
die();
break;
}
?>
But the issue I'm facing is getting the alert success message multiple times. It is expected to show the alert message only once but in current scenario it's showing multiple times. Can anyone hep me in correcting this issue please?
You have nested click handlers -
Every time you click on .fixed you are binding a new click handler on #fixedPop_url. And that is why your .get is executing multiple times
you can use .off() to fix this -
$("#fixedPop_url").off('click').on('click',function(event) {

Jquery if statement not working even if the statement is true

I have a simple if statement where when i send this certain data to the database, i want the php code to send bake a code that tells javascript its ok to continue, but if the php script sends back a bad code, javascript is to now move forward and display a certain text or something.
The php code works fine but for some reason my javascript files would not work at all.
My javascript is suppose to ajax request to parse.php and receive the data that parse.php sends back to it, if parse.php says 200 its suppose to load in specific items.
Here is the code for one of my systems:
$(document).ready(function(){
$("#chatForm").submit(function(){
var chatHash = $("#chatHash").val();
var body = $("#chatPoster").val();
var by = $("#userBy").val();
if(chatHash != "" && body != ""){
$.post('parse.php',{chatHash: chatHash, body: body, userBy: by},function(data){
if(data == "200"){ // Right here is where its messing up
$("#chatPoster").val("");
$.get('getChatMessages.php?hash=' + chatHash,function(data2){
$(".allMsgs").html(data2);
});
} else {
alert('Critical error');
}
});
} else {
alert('Error');
}
});
});
Here is the code for the parse.php page:
$chat = new ChatSystem;
if(isset($_POST['chatHash']) && isset($_POST['body']) && isset($_POST['userBy'])){
$chat->sendMessage($_POST['userBy'],$_POST['chatHash'],$_POST['body']);
}
Here is the code from the class ChatSystem that the parse.php page is referring to:
public function sendMessage($user,$hash,$body){
global $db;
$date = date("Y-m-d");
$time = date("H:i:s");
$timestamp = "$date $time";
if(empty($user) == false && empty($hash) == false){
$db->query("INSERT INTO chat_messages VALUES('','$user','$body','$timestamp','','0','$hash')") or die("error");
echo '200';
}
}
Even though my php code works perfectly the javascript still messes up. My php code sends back 200 like i ask it to but yet the jquery messes it up
Have a look here, http://api.jquery.com/jquery.post/.
You need a second parameter to the success callback function to be able to catch the response status code.
I.E. function(data,statusCode){ // check the status code here}

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