Q:

jQuery loop through table and get element

i've got some form input elements in an html table like this:
<table>
    <thead>
    ....
    </thead>
    <tr>
        <td><input type="text" name="n_time" id="5030c9261eca0" value="2012" /></td>
        <td><input type="text" name="n_name" id="5030c9261eca0" value="a name" /></td>
        <td><textarea name="n_comment" id="5030c9261eca0">bla</textarea></td>
    </tr>
</table>

now, i need to send this form data using $.post to my PHP processing page
which looks something like
if($_POST['data']){
    $array = json_decode($_POST['data']);

}

so i need to get all my form elements and somehow made then into JSON 
and this is what i did:
// assume i can get 5030c9261eca0 from my predefined vars...
$my_array = $("#5030c9261eca0").map(function () { return $(this).is("input")?$(this).val():$(this).text(); } );
//now convert
JSON.stringify($my_array);
// the conversion failed with : Uncaught TypeError: Converting circular structure to JSON 

this error poped up:
Uncaught TypeError: Converting circular structure to JSON 

how do i fix this? 
also, if i do regluar HTTP post via HTML forms, i can recieve form data like $_POST['n_name'] in PHP if i have a HTML form element with attribute n_name, how can i accomplish the same with the above? 

A:

First loop through all tr, then loop trought all input,textarea and push gathered values to array. 
var data = [];      
$('table tr').each(function(){
    var row = {};
    $(this).find('input,textarea').each(function(){
        row[$(this).attr('name')] = $(this).val();
    });
    data.push(row);
});

// now you can use "data" :)

Example data:
[0][n_time] = foo
[0][n_name] = bar
[0][n_comment] = 123
[1][n_time] = foo
[1][n_name] = bar
[1][n_comment] = 123
...

jQuery:
$.post("test.php", { 'mydata': data } );

PHP:
foreach($_POST['mydata'] as $row) {
    echo $row['n_name'];
}

It's good idea to convert it to jQuery function:
(function( $ ) {
  $.fn.tableData = function() {
    var data = [];      
    $(this).find('tr').each(function(){
        var row = {};
        $(this).find('input,textarea').each(function(){
            row[$(this).attr('name')] = $(this).val();
        });
    });
    return data;
  }
})( jQuery );

// Usage:

$.post("test.php", { 'mydata': $('table').tableData() } );

