Unable to pass PHP variable to a Javascript function

Question

I am trying to get a PHP variable to pass values to a sample javascript but nothing shows up if I tried to echo the result.

I tried passing regular strings as arguments and those worked fine. It just doesn't seem to be working if I tried to pass PHP variables as arguments.

AES (Rijndael) Encryption Test in JavaScript

<script type="text/javascript" src="Decrypt.js"></script>


</head>

<body>
<?php
mysql_connect("localhost","root","");
mysql_select_db("encryption") or die(mysql_error());
$userId = $_POST['userId'];


    if (($_SERVER['REQUEST_METHOD'] == 'POST') && ($_POST['key'] == ""))
    {

        $query = mysql_query("select * from employee_details where id = '$userId'");
            if($row=mysql_fetch_assoc($query))
                {
                    echo '<tr>';
                    foreach($row as $value)
                    echo '<td>'.$value.'</td>';
                    echo '</tr>';
                }

            else { echo "No rows returned"; }}
    else if (($_SERVER['REQUEST_METHOD'] == 'POST') && ($_POST['key']))
        {

           $columname = "ciphertext";
           $tablename = "employee_details";



                function getField($field, $tbl_name, $condition)
            {

                $result = mysql_query("SELECT $field FROM $tbl_name WHERE id = ".$condition);

                 return @mysql_result($result, 0);
            }

                $myValue = getField($columname,$tablename,$userId);

                echo "Ciphertext = $myValue";
                echo "<br>";
                //doDecryption();

        }
        echo '<script type="text/javascript">
doDecryption("<?php $myValue; ?>");
</script>';
echo "whats happening";
?>
</body>
</html>

The JS file

function doDecryption(param)
 {
    document.write(param);
    document.write("Programming change");
 }

Thanks in advance. Any help much appreciated!!!!

Upvotes for whoever actually explains why this isn't working rather than offering code examples. There are two types of PHP strings and the semantics of <?php. A whole 10 points up for grabs! — Stefan Mai
– Stefan Mai, Commented Dec 3, 2010 at 8:14
possible duplicate of Calling javascript function with php code — Quentin
– Quentin, Commented Dec 3, 2010 at 8:14
The reason it's not woking is because he forgot the call to "echo". — Ronnis
– Ronnis, Commented Dec 3, 2010 at 8:45
Your problem is nested <?php ?> tags. you can't use php tags inside the echo. — Shakti Singh
– Shakti Singh, Commented Dec 3, 2010 at 9:23

EvilMM · Accepted Answer · 2010-12-03 08:19:46Z

3

You do not need the echo statement to build the javascript-part, just try this:

<script type="text/javascript">
  doDecryption("<?php echo $myValue; ?>");
</script>

But if you do not want to change it and you want to write out the -Block via echo, you should not use the "

echo '<script type="text/javascript"> doDecryption(' . $myValue . '); </script>';

edited Dec 3, 2010 at 8:19

answered Dec 3, 2010 at 8:12

EvilMM

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1 Comment

EvilMM Over a year ago

Can you post the generated JavaScript?

DiAngelo · Accepted Answer · 2010-12-03 08:16:59Z

1

I think you should try to echo your var:

doDecryption("<?php echo $myValue; ?>");

answered Dec 3, 2010 at 8:16

DiAngelo

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Comments

atcuno · Accepted Answer · 2010-12-03 08:12:43Z

0

I don't have access to PHP atm to check, but I think its because you echo uses single quotes which won't evaluate the variable. Use double quotes for the echo and escape your " inside the string and see what happens

answered Dec 3, 2010 at 8:12

atcuno

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Comments

Adeel · Accepted Answer · 2010-12-03 08:20:35Z

0

yes its better to "echo" your variable.

answered Dec 3, 2010 at 8:20

Adeel

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Comments

Shakti Singh · Accepted Answer · 2010-12-03 08:21:21Z

0

or change your echo to this

echo '<script type="text/javascript">
doDecryption("'.$myValue.'");
</script>';

answered Dec 3, 2010 at 8:21

Shakti Singh

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Comments

Lobo · Accepted Answer · 2010-12-03 08:10:16Z

Try this,

<script type="text/javascript" src="Decrypt.js"></script>
<?php
mysql_connect("localhost","root","");
mysql_select_db("encryption") or die(mysql_error());
$userId = $_POST['userId'];


    if (($_SERVER['REQUEST_METHOD'] == 'POST') && ($_POST['key'] == ""))
    {

        $query = mysql_query("select * from employee_details where id = '$userId'");
            if($row=mysql_fetch_assoc($query))
                {
                    echo '<tr>';
                    foreach($row as $value)
                    echo '<td>'.$value.'</td>';
                    echo '</tr>';
                }

            else { echo "No rows returned"; }}
    else if (($_SERVER['REQUEST_METHOD'] == 'POST') && ($_POST['key']))
        {

           $columname = "ciphertext";
           $tablename = "employee_details";



                function getField($field, $tbl_name, $condition)
            {

                $result = mysql_query("SELECT $field FROM $tbl_name WHERE id = ".$condition);

                 return @mysql_result($result, 0);
            }

                $myValue = getField($columname,$tablename,$userId);

                echo "Ciphertext = $myValue";
                echo "<br>";
                //doDecryption();

        } ?>
<script type="text/javascript">
doDecryption("<?php $myValue; ?>");
</script>

</head>

<body>
<?php
echo "whats happening";
?>
</body>
</html>

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