Javascript variable passed to PHP session in Wordpress - javascript

I am not sure if this is the best way to do it, but I have a button that when pressed it call a onClick JS function and it passed two parameters. I want to save those two parameters on a php session, then load another page and use those values.
So, I know that if I use something like this on PAGE !:
<?php
session_start();
$message1 = "A message";
$message2 = "Another message";
$_SESSION['routineName'] = $message1;
$_SESSION['dayName'] = $message2;
?>
I can go to PAGE 2, and by using $_SESSION['routineName'] I can use that info.
So, on PAGE 1 I have that code inside the function that is called with my onClick:
function trackIt(routine, dayName)
{
<?php
session_start();
$message1 = "A message";
$message2 = "Another message";
$_SESSION['routineName'] = $message1;
$_SESSION['dayName'] = $message2;
?>
}
I tried things like:
function trackIt(routine, dayName)
{
<?php
session_start();
$_SESSION['routineName'] = ?> routine; <?php
$_SESSION['dayName'] = $message2;
?>
}
and others, but nothing works.
And this is how I am calling the onClick (trackIt) function:
echo('<td colspan="3" style="background-color:#005673; text-align:right; padding: 4px 0px;">
<button class="btnTrack" onClick="trackIt(\'' . $name . '\' , \'' . $nameday1 . '\')" >Track It!</button></td>');
What I want to do is to save both, routine and dayName, into the session.
Is it possible to save JS variables/parameters into PHP Session?
PS: I am using Wordpress.
Thanks!

The PHP code you put in your files is not executed at Javascript run time, it is executed even before the page gets sent to the client. So you can't access $_SESSION from anywhere within your content, you need to do that from Wordpress's code. Usually this is done via a plugin.
You need to pass your Javascript variables to a server side PHP. As #Grasshopper said, the best (or at least most maintainable way) is through AJAX:
// This is your JAVASCRIPT trackit function
function trackIt(routine, day) {
$.post(
'/wp-setvar.php',
{
routine : routine,
day : day
}, // You can add as many variables as you want (well, within reason)
function success(data) {
// Here we should receive, given the code below, an object
// such that data.result is a string saying "OK".
// Just in case you need to get back something from the server PHP.
// Otherwise just leave this function out.
}
);
};
On the server, you need to create a specific file to accept the incoming variables (it would be best if you did this from a plugin, in order not to add files outside the installation: such practices are frowned upon by security scanners such as WordFence). This here below is a butcher's solution.
<?php /** This is wp-setvar.php */
/** Set up WordPress environment, just in case */
require_once( dirname( __FILE__ ) . '/wp-load.php' );
session_id() || session_start();
nocache_headers();
// DO NOT, FOR ANY REASON, ACCESS DIRECTLY $_SESSION
// ONLY USE A VARIABLE WITHIN $_SESSION (here, "ajjx")
// OTHERWISE THIS MAY ALLOW ANYONE TO TAKE CONTROL OF YOUR INSTALLATION.
$_SESSION['ajjx'] = $_POST;
Header('Content-Type: application/json;charset=utf8');
die(json_encode(array(
'result' => 'OK', // This in case you want to return something to the caller
)));
Now whenever you need the session-saved variable, e.g. "routine", you put
<?php
...
$value = '';
if (array_key_exists('ajjx', $_SESSION)) {
if (array_key_exists('routine', $_SESSION['ajjx']) {
$value = $_SESSION['ajjx']['routine'];
}
}
Or you can define a function in your plugin,
function ajjx($varname, $default = '') {
if (array_key_exists('ajjx', $_SESSION)) {
if (array_key_exists($varname, $_SESSION['ajjx']) {
return $_SESSION['ajjx'][$varname];
}
}
return $default;
}
Then you just:
<?php print ajjx('routine', 'none!'); ?><!-- will print routine, or "none!" -->
or
<?php print ajjx('routine'); ?><!-- will print nothing if routine isn't defined -->
An even more butcherful solution is to add the function definition above within wp-config.php itself. Then it will be available everywhere in Wordpress. Provided you have access to wp-config.php. Also, backup wp-config first and use a full FTP client to do it; do not use a Wordpress plugin to edit it, since if wp-config crashes, the plugin may crash too... and you'll find yourself in a my-can-opener-is-locked-within-a-can situation.
If you don't feel comfortable with some of the above, it's best if you do nothing. Or practice first on an expendable Wordpress installation that you can reinstall easily.

Related

How to mix php inside javascript?

I have a php code as shown below in which there is an if condition.
php:
if(mysqli_num_rows($result1) > 0){ // Line X
while($row = mysqli_fetch_array($result1)){
if($row['open'] == "true") {
if(!isset($_SESSION['admin'])) {
$message = "user " . $row['user_name'] . " is currently editing the form. Want to take over ?"; // Line B
echo "<script type='text/javascript'>if(confirm('$message')) { } else { };</script>"; // Line A
}
break;
}
}
}
I was able to integrate $message at Line B.
I am wondering what changes I should do at Line A so that I can integrate the following code in the curly braces of the if(confirm('$message') block:
$username = $_SESSION['user_name'];
$open="true";
$write="1";
$stmt=$connect->prepare("UPDATE trace_users SET write=0 WHERE write=1"); // revoke write access of all users
$stmt=$connect->prepare("UPDATE trace_users SET open=?, write=? WHERE user_name=?");
$stmt->bind_param('sss', $open, $write, $username);
$stmt->execute();
Unfortunately user1950349, this is a bit more complex than it may seem because your idea is closer to how a desktop app would where there is a message loop which allows the code to respond to user input. But with a webpage generated by php and sent over the internet, we do not have a message loop to work with. Thus, we have figure out a way to get the server and the user's computer to message back and forth without any additional webpage loads.
This is where AJAX would come into play; however, an explanation of how to use that for your use case would depend on how you implement AJAX. For instance, you might use jQuery or some other javascript library.
It is a good practice if you avoid mixing two different languages together.
When mixing these two the complexity of your code increases.
Since you need the answer here you go
echo "<script type='text/javascript'>if(confirm(" . $message . ")) { } else { };</script>";
Inside echo's double/single quotes(" / ') everything is considered as a string, so to access your PHP variable you need to use the concatenation method to use that PHP variable.
if(confirm(" . $message . "))
UPDATE
You need to follow the same steps, as described above. You need to use the string concatenations.
But that will be very complex and as well as very difficult to make debugging.
You can use a better approach using XHR request or you can design the PHP code in a better way to use it with your JavaScript code.

PHP method calls from Javascript not showing up in Wordpress source

I am running a Wordpress website, and trying to call PHP methods from my Javascript code.
When a button is tapped, the saverFoo() Javascript method is called, and attempts to call the PHP method save_image_data().
function saverFoo() {
var dataURL = canvas.toDataURL();
<?php echo save_image_data(dataURL); ?>;
}
function loaderFoo() {
var loadedImage = <?php echo loadimagedata(); ?>;
console.log(loadedImage);
}
The PHP method's implementation is in the function.php file, and is simply attempting to save some image data (dataURL) in the user's meta
function save_image_data($imageData) {
global $current_user;
update_user_meta( $current_user->ID, 'user_design', $_POST['$imageData']);
}
function loadimagedata() {
global $current_user;
$old_notes = get_user_meta($current_user->ID, 'user_design', true);
return $old_notes;
}
Inspecting my web-page in Chrome, shows me an empty space where loaderFoo () (javascript) is supposed to be calling loadimagedata() (php) , and loadedImage is an undefined variable, when I try to log it, such as:
function loaderFoo() {
var loadedImage = ;
console.log(loadedImage);
}
Not sure what fundamental mistake I'm making here.
Always remember that PHP runs on the server side, and javascript on the client side. So we have an order here, the server receives the request PHP processes what it should process and render the page, only here Javascript will be executed.
In this example, when the 'saverFoo()' function is executed, this function <? Php echo save_image_data (dataURL); ?>; has already been written on the page. PHP will not be able to get the information contained in the dataURL variable, not on this way. To do this, we must make a request to the server with this desired information, but with an "image" is not trivial to do this, as there is a limit on the size of the post when using a normal String field.
function saverFoo () {
    var dataURL = canvas.toDataURL ();
    <? php echo save_image_data (dataURL); ?>;
}
PHP doesn't work that way. It is a pre-processor. It is all run and done server side and the resulting text/html/binary data/whatever is sent out to the client. In the case of a content type of text/html the browser will load it, parse it, render it, and run whatever javascript is called.
How you can mix PHP and JavaScript in-line like that would be to use PHP to fill in variables. For example
alert("<?php print($_SERVER['SCRIPT_FILENAME']); ?>");
would work because the client would see
alert("/path/to/foo.php");
and render that for the user.
To really interact with PHP using JavaScript, you'll want to look into using a http based REST type service and perhaps one of the various popular tool sets like Angular, Vue, etc.

Facebook PHP SDK V4: two login buttons

I would like to have two login buttons on my page. I'm not too familier with the coding of the SDK, is this possible?
One button works fine, but the second button doesn't. It just changes the url to index.php?code=wKdOAOLK... without logging in.
Any workaround?
code:
// added in v4.0.0
require './facebook-sdk/autoload.php';
use Facebook\FacebookSession;
use Facebook\FacebookRedirectLoginHelper;
use Facebook\FacebookRequest;
use Facebook\FacebookResponse;
use Facebook\FacebookSDKException;
use Facebook\FacebookRequestException;
use Facebook\FacebookAuthorizationException;
use Facebook\GraphObject;
use Facebook\Entities\AccessToken;
use Facebook\HttpClients\FacebookCurlHttpClient;
use Facebook\HttpClients\FacebookHttpable;
use Facebook\GraphUser;
// start session
// init app with app id and secret
FacebookSession::setDefaultApplication( 'x','x' );
// login helper with redirect_uri
$helper = new FacebookRedirectLoginHelper('http://localhost/' );
try {
$session = $helper->getSessionFromRedirect();
} catch( FacebookRequestException $ex ) {
// When Facebook returns an error
} catch( Exception $ex ) {
// When validation fails or other local issues
}
// see if we have a session
if ( isset( $session ) ) {
...
}
Buttons, both the same code:
<?php echo '<img src="facebook.png">'; ?>
<?php echo '<img src="facebook.png">'; ?>
Facebook uses a state parameter in its login process, to prevent CSRF attacks. That parameters is a random value that gets stored into the session, and is checked for a match in the next step.
Now, the getLoginUrl method generates a new random value for state each time it is called. So by calling this method twice, you are generating two different random state values, and therefor the second one overwrites the first one stored into the session, so in the end only one of them will match, and the other one won’t and will therefor cause an error.
So, don’t call getLoginUrl twice – instead, call it once, store the returned URL, and only output it two times.
$facebookLoginURL = $helper->getLoginUrl();
<?php echo '<img src="facebook.png">'; ?>
<?php echo '<img src="facebook.png">'; ?>

Reloading url page with ajax

i'm trying to refresh page every 3 second, the url page change with $_GET variable.
i'm trying to save $_GET var into session and cookie, but get error header has already sent.
how to change url after page reload ?
here my script :
Index.php
<?php
session_start();
$skill =$_SESSION['skill'];
?>
<script type="text/javascript">
var auto_refresh = setInterval(function () {
$('#src2').load('monitor.php?skill=<?php echo $skill;?>').fadeIn("slow");
}, 3000);
</script>
monitor.php
<?php
include "conn.php";
session_start();
$_SESSION['skill'] = $_GET['skill'];
if ($_SESSION['skill']=='')
{
$a ="bro";
$_SESSION['skill']=4;}
elseif ($_SESSION['skill']==4){
$a = "yo";
$_SESSION['skill']='5';
}
elseif ($_SESSION['skill']==5){
$a = "soo";
}
?>
First off, "headers already sent" means that whichever file is triggering that error (read the rest of the error message) has some output. The most common culprit is a space at the start of the file, before the <?php tag, but check for echo and other output keywords. Headers (including setting cookies) must be sent before any output.
From here on, this answer covers how you can implement the "refresh the page" part of the question. The code you provided doesn't really show how you do it right now, so this is all just how I'd recommend going about it.
Secondly, for refreshing the page, you will need to echo something at the end of monitor.php which your JS checks for. The easy way is to just echo a JS refresh:
echo '<script>window.location.reload();</script>';
but it's better to output some JSON which your index.php then checks for:
// monitor.php
echo json_encode(array('reload' => true));
// index.php
$('#src2').load('monitor.php?skill=<?php echo $skill;?>', function(response) {
if (response.reload) window.location.reload();
}).fadeIn('slow');
One last note: you may find that response is just plain text inside the JS callback function - you may need to do this:
// index.php
$('#src2').load('monitor.php?skill=<?php echo $skill;?>', function(response) {
response = $.parseJSON( response ); // convert response to a JS object
if (response.reload) window.location.reload();
}).fadeIn('slow');
try putting
ob_start()
before
session_start()
on each page. This will solve your problem.
Without looking at the code where you are setting the session, I do think your problem is there. You need to start the session before sending any data out to the browser.
Take a look at: http://php.net/session_start
EDIT:
Sorry, a bit quick, could it be that you send some data to the browser in the 'conn.php' file? Like a new line at the end of the file?

How to make a menu that will change the language of my site

I am new to web development and I want my site to have a drop-down menu that will change the language of my site.I want a solution that will not require me to create a whole new html of the new site. I also want a way to make an input field that will ask users to add a number and then it will automatically add a word after the number.
Perhaps this maybe of some use to you - http://code.google.com/p/jquery-translate/.
Not sure what the second part of the sentence is but a somewhat easy way of doing this is server-side scripting. For example, if you are using PHP, I would recommend you echo the a variable instead of actually typing the contents in the place it belongs. Instead, store the content in a database and then load the content from a database depending on what language is selected (store this a session variable), store it in the variable and when the variable is echoed, bam.
Create in PHP by using $_GET[l];
<?php
if($_GET[l]=='en')
{
echo 'Welcome';
}
else if($_GET[l]=='sk')
{
echo 'Vítajte';
}
else if($_GET[l]=='de')
{
echo 'Wilkommen';
}
else
{
echo ''; //Here set your default language. For example if is not set- automatically to english
}
?>
Menu:
<?php
if(isset($_GET[topic]))
{
//This is code, if you use another $_GET[...]
//Without this, page will crash ,while it shows another thing
echo 'English';
echo 'Slovensky';
echo 'Deutsch';
//?l=lang changes to &l=lang
}
else
{
//Link with normal ?l=lang, cause page does not use another $_GET[...]
echo 'English';
echo 'Slovensky';
echo 'Deutsch';
}
?>

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