write json to a file using jQuery and Ajax and PHP -

i'm trying write json file based upon filled in form

so used external library jquery converts form legitimate json. when console.log output valid json data returned.

so whenever pass data php using $.ajax , write content file php saves file inside says "null"

here ajax:

$(document).ready(function() {     var json = $("#user-form").serializejson();     $.ajax({         url: "writejson.php",         type: "post",         data: json,         processdata: false,         contenttype: 'application/json'     }); }) 

and here php:

<?php     $myfile = "kiosk.json";     $fh = fopen($myfile, 'w') or die("can't open file");     fwrite($fh,var_export($_post['data'], true));     fclose($fh); ?> 

and here outputted file says:

null 

i tried looking here first , tried numerous options none of them seem save correct data. strange.

thanks in advance!

you change json string this

 var json = $("#user-form").serializejson(); 

to this

 var json = {data: $("#user-form").serializejson()}; 

that way when try retrieve $_post['data'], set because defined it.

edit: important point shuyinsama - pointed out have use json.stringify method on json objects before posting them php:

in case did:

var jsontext = json.stringify($("#user-form").serializejson());  var json = {data: jsontext}; 

and use first php file write valid json file.

and remember can use json_decode(); within php if ever need processing on json data, , json_encode();, respectively.