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up vote 1 down vote favorite

here is the code.......here i am passing a javascript array to php... something is going wrong........

html:

    <html>
    <body onload="aa()" >
<script language="javascript">
function aa()
{
var a, s;
a = [ 'one', 'two', 'three'];
s = JSON.stringify( a );
document.getElementById("fb_user").innerHTML= s;
}

    </script>
<form action="check1.php" method="post">
    <label id="fb_user"> </label>
<input type="submit" value="submit"/>
</form>
</body>
</html>

php code:

<?php

$fb_usr_id =json_decode(  $_POST['fb_user'], true );

    echo $fb_usr_id;
    ?>

when $fb_usr_id is echoed nothing is printed??

share|improve this question
    
You are adding the JSON string to the label, instead of the input element. –  Pekka 웃 Jun 13 '11 at 16:13
    
@Pekka what u say pekka. cannot understand.....? –  ask123 Jun 13 '11 at 16:32
    
The code you have provided just creates a form it does not SUBMIT that form. Are you SUBMITting it manually? –  James Jun 13 '11 at 16:37
    
@James it submits the form.. why u say it is not submitting the form –  ask123 Jun 13 '11 at 16:39
    
Your code does this- create a form, populate the form with some stuff. It is up to the user to click the submit button. Is that correct? –  James Jun 13 '11 at 16:42

4 Answers 4

up vote 2 down vote

Contents of label tags are not submitted.

Try changing
<label id="fb_user"> </label> to
<input type="hidden" name="fb_user" id="fb_user">

share|improve this answer
1  
also change document.getElementById("fb_user").innerHTML= s; with document.getElementById("fb_user").value= s; –  venimus Jun 13 '11 at 16:14
    
@venimus @simshaun made the changes.. nothing is displayed still.. –  ask123 Jun 13 '11 at 16:17
    
@venimus Absolutely not, the JavaScript function is called by onload. –  phihag Jun 13 '11 at 16:20
    
Guess I should have mentioned the JS change. Anyway, use Firebug or equivalent tool to ensure the contents of the hidden field are being updated correctly before form submission. –  simshaun Jun 13 '11 at 16:31
up vote 1 down vote 
    <html>
    <body onload="aa()" >
<script language="javascript">
function aa()
{
var a, s;
a = [ 'one', 'two', 'three'];
s = JSON.stringify( a );
document.getElementById("fb_user").value = s;
}

    </script>
<form action="check1.php" method="post">
<input type="hidden" name="fb_user" id = "fb_user" value="">
<input type="submit" value="submit"/>
</form>
</body>
</html>

On the backend do this first to check the validity of the posted variable as being json

var_dump( $_POST );
share|improve this answer
    
when i put var_dump( $_POST ); in php file. i get : array(0) { } –  ask123 Jun 13 '11 at 16:22
    
make sure that the var_dump() I mentioned is on the page check1.php. As as sanity check, put the word "test" as the value in the hidden field temporarily then you will have identified if it is a PHP or JS problem... and as others have pointed out you need to press the submit button manually before this will work. –  Cups Jun 13 '11 at 18:17
up vote 0 down vote

The contents of labels are not posted to the server. Instead, use <input type="hidden"> for inputs not intended to be editable by users:

<input name="fb_user" id="fb_user" type="hidden" />

Also, you should not change the innerHTML if you just want set the value of an input element. Instead, assign the aptly named value property.

share|improve this answer
    
@phihag made that change.still nothing is printed....... –  ask123 Jun 13 '11 at 16:15
    
@ask123 Can you post a complete example code or a URL to the running instance? –  phihag Jun 13 '11 at 16:17
    
@phihag the above is complete code only.... –  ask123 Jun 13 '11 at 16:19
    
@ask123 Did you maybe forget to set the name attribute of the input element? –  phihag Jun 13 '11 at 16:22
    
@ask123 You should remove the closing </label>. With that exact code , I get the output Array (php's string representation of an array). –  phihag Jun 13 '11 at 16:26
up vote 0 down vote

Here is how you should do it:

<html>
    <body>
    <form action="check1.php" method="post">
        <label id="fb_users_list"></label>
        <input type="hidden" name="fb_user" id="fb_user" value="" />
        <input type="submit" value="submit"/>
    </form>
    <script type="text/javascript">
        (function(){
            var a, s;
            a = [ 'one', 'two', 'three'];
            s = JSON.stringify( a );
            document.getElementById("fb_users_list").innerHTML = s;
            document.getElementById("fb_user").value = s;
        })();
    </script>
    </body>
</html>

Please do not use body onload="", because you open up holes to XSS attack. Just put your script below your form, or better of at the end of the body, and you won't need an onload event.

share|improve this answer
    
ya shef i had removed onload. but nothing display. any suggestion?? –  ask123 Jun 13 '11 at 16:34
    
@ask123 did you try my code above? Is it displaying anything at all before you submit, or not? –  Shef Jun 13 '11 at 16:45
    
when i click submit button .the php check1.php executes and displays : Array . what does this mean –  ask123 Jun 13 '11 at 16:54
    
@ask123: Do you need to have the fb user ids in an array, or you can have them in a list as well? I mean can you change this a = [ 'one', 'two', 'three']; to this a = 'one, two, three';? –  Shef Jun 13 '11 at 20:57

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