How to return a php value to the jQuery post

Question

I just can't get my head around it. What do I need to write in my php file to return something to the $.post function?

<script type="text/javascript">
    function SubmitToDatabase(uName, uComment)
    {
        $.post("write_something_to_mysql_b.php", {name: uName, comment: uComment});
        return false;
    }
</script>

This works, but there is no return value from the PHP file

This is nothing to do with PHP; this is the basic properties of the asynchronous nature of AJAX requests; http://stackoverflow.com/questions/562412/return-value-from-function-with-an-ajax-call — Matt, Jan 19 '13 at 15:26
Read up on [jQuery.post()](http://api.jquery.com/jQuery.post/). There are a ton of working examples. — SeanWM, Jan 19 '13 at 15:26
use complete callback ... as noted read in docs how to do it — charlietfl, Jan 19 '13 at 15:27

Igor Parra · Accepted Answer · 2013-01-19T15:48:01.993

2

// php:
$output['result']    = 'hello!!!';
echo json_encode($output); // json encode here
exit;

// jquery:
$.post(
"write_something_to_mysql_b.php",
{
    name : uName,
    comment : uComment
},
function(output) { // callback function to catch your php output
    // console.debug(output['result']);
    alert(output['result']);
    // output hello!!!
},
'json'); // json requirement here

json is just one of the possibilities to require data from backend side. Others are: xml, json, script, text, html. For each one of these formats you must to return data from backend in a suitable way. For example for text just echo 'hello!!!; exit;

edited Jan 19 '13 at 15:48

answered Jan 19 '13 at 15:38

Igor Parra

10,214
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@wubbewubbewubbe you're welcome. the other answers are good contributions too... – Igor Parra Jan 19 '13 at 15:54
Some things just can't be guessed by someone who does not write pages on a regular basis. I've been studing http://api.jquery.com/jQuery.post/ for hours. – wubbewubbewubbe Jan 19 '13 at 16:01
@wubbewubbewubbe That's right, that's why we have SO! but the first is study by himself. Good! – Igor Parra Jan 19 '13 at 16:04

score 1 · Answer 2 · answered Jan 19 '13 at 15:37

First of all, make sure jQuery is hitting your PHP file. Use the developer tools in Chrome or download Firebug for Firefix, go to the 'Network' tab and when your JavaScript function SubmitToDatabase() is executed, check to see any network activity. If it's accessing the wrong PHP page, it'll show a 404.

If it's accessing the correct PHP page, check Firebug to see what value is returned. To return a value in PHP for a JavaScript call, you need to make sure you're using echo rather than return.

+1 for the important advice about debug with firebug to check php responses — Igor Parra, Jan 19 '13 at 15:58

score 1 · Answer 3 · answered Jan 19 '13 at 15:38

1

See jQuery.post(). You must add a success function, if you want to do something with the PHP result

function SubmitToDatabase(uName, uComment)
{
    $.post("write_something_to_mysql_b.php", {name: uName, comment: uComment},
        function(data) { alert(data); });
    return false;
}

answered Jan 19 '13 at 15:38

Olaf Dietsche

72,253
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+1 for the link to the life's water source :) – Igor Parra Jan 19 '13 at 15:57

How to return a php value to the jQuery post

3 Answers3