Using variable on php to create another variable in JS

Question

I'm having a hard time getting the value of a specific variable in php to use in js. This is my code in php:

<?php
require("connection.php");

$sql_cmd = "SELECT * FROM tbstatus";

$stmt = $con->prepare($sql_cmd);
$stmt->execute();

echo "<h2>STATUS OF THE BABY</h2>";

while ($result = $stmt->fetch(PDO::FETCH_ASSOC)) {
    echo "<h4>" . $result['status'] . "</h4>";
}
?>

I want to get the value of this ($result['status']) and pass it on the variable pos in js. This is my js code:

setInterval(function() {
    $("#position").load('refresh.php');
    notif();

}, 1000);

function notif() {
    var pos = $('PHP VARIABLE HERE').val();
    alert(pos);
}

Thanks for your help.

Possible duplicate of [How to pass variables and data from PHP to JavaScript?](https://stackoverflow.com/questions/23740548/how-to-pass-variables-and-data-from-php-to-javascript) — yivi, Nov 24 '18 at 10:27

score 1 · Answer 1 · answered Nov 23 '18 at 05:34

1

The easiest way is to output it to javascript directly:

?>
<script type="text/javascript">
window.MY_PHP_VAR = <?php echo json_encode($myPhpVar); ?>;
</script>
...

window.MY_PHP_VAR now contains your php variable

answered Nov 23 '18 at 05:34

Blue

22,608
7
62
92

score 1 · Answer 2 · edited Nov 25 '18 at 18:28

1

if your javascript code is on same page where the result is comming then you can use this

var pos =  `<?php echo $result['status'] ?>`;

var pos =  `<?= $result['status'] ?>`;

edited Nov 25 '18 at 18:28

Blue

22,608
7
62
92

answered Nov 23 '18 at 06:19

Akhilesh

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1
6
21

Kagiso Marvin Molekwa · Answer 3 · 2018-11-23T08:50:10.020

-1

you could try giving an id or class to the status.
then in JavaScript you could then get the value of the id or class.

PHP

<?php
require("connection.php");

$sql_cmd = "SELECT * FROM tbstatus";

$stmt = $con->prepare($sql_cmd);
$stmt->execute();

echo "<h2>STATUS OF THE BABY</h2>";
while ($result = $stmt->fetch(PDO::FETCH_ASSOC)) {
    echo '<h4> <span class="status">' . $result['status'] . '</span></h4>';
}

?>

JavaScript

var oldStatus = '';

setInterval(function() {
    $("#position").load('refresh.php');
    notif();
}, 1000);

function notif() {
    // note that since we used a class, you will get the value of the first element only.
    var pos = $('.status').text(); // use .text() instead of .val()
    if (pos.toLowerCase() == 'out' && pos != oldStatus){
        oldStatus = pos;
        alert(pos);
    }
}

edited Nov 23 '18 at 08:50

answered Nov 23 '18 at 06:13

Kagiso Marvin Molekwa

915
1
9
25

It's working now. Thank You. But I have a little bit concern. Since I have setInterval in my js, every second it will alert me with the value of status. I want is to just alert me once, if the value of the status does not change. Is it possible? Thank you – Gerald Manibale Nov 23 '18 at 06:27
replace `setInterval` with `setTimeout` – Kagiso Marvin Molekwa Nov 23 '18 at 07:10
If I use setTimeout, it will not automatically refresh my web. I needed that to get the latest value from my database – Gerald Manibale Nov 23 '18 at 07:21
i've modified my answer. check it out. – Kagiso Marvin Molekwa Nov 23 '18 at 07:25
I don't understand this. I want it to notify me when the status is "Out". – Gerald Manibale Nov 23 '18 at 08:01
i've modified my answer. check it out. – Kagiso Marvin Molekwa Nov 23 '18 at 08:50

score -1 · Answer 4 · answered Nov 23 '18 at 06:30

===============
// refresh.php
===============

<?php  
require("connection.php");
$sql_cmd = "SELECT * FROM tbstatus";
$stmt = $con->prepare($sql_cmd);
$stmt->execute();

echo "<h2>STATUS OF THE BABY</h2>";

while ($result = $stmt->fetch(PDO::FETCH_ASSOC)) {
      echo "<h4>" . $result['status'] . "</h4>";
      echo "<script> alert('". $result['status'] ."'); </script>";
      /* If the $result['status'] is 'success' the above line will be converted to:
       echo "<script> alert('success'); </script>";
      */
}

?>

so, every time the refresh.php loads, the script is going to get executed.

However, I suggest you to assign a id or class attribute to your h4 where you are echoing your status and access the value using the selectors in the javascript.

Using variable on php to create another variable in JS

4 Answers4

PHP

JavaScript