Reading json object sent via ajax in php file

Question

I am trying to solve one problem with reading json object sent via ajax request in php file and I am keep gettin null in the console.

Javascript file

//create function to send ajax request
function ajax_request(){
  console.log("hello");
 var post_data = {
    "news_data" : 'hello',
    "news_date" : '1st march'
}
$.ajax({
    url : 'index.php',
    dataType : 'json',
    type : 'post',
    data : post_data,
    success : function(data){
        console.log(data);
    }
 });
}

//on click event
$('#news_post_button').on('click', ajax_request);

and php file which is only for testing to see what i get

<?php
 header('Content-Type: application/json');



  $aRequest = json_decode($_POST);

  echo json_encode($aRequest[0]->news_data);

?>

score 1 · Answer 1 · answered Mar 05 '15 at 14:17

Try using json_last_error function. And print out Your post as a string:

print_r($_POST);
echo '<br /> json_last_error: '.json_last_error();

This way You will see what You got and what potentially had gone wrong.

For testing this kind of things I suggest Postman chrome extension.

score 0 · Answer 2 · edited May 23 '17 at 11:44

You aren't sending a JSON object at all.

You are passing jQuery an object, so it will serialise it using standard form encoding.

<?php
   header('Content-Type: application/json');
   echo json_encode($_POST["news_data"]);
?>

If you want to actually send a JSON text, then you need to:

Set the content type of the request
Encode the data as JSON and pass it as a string to data

See this answer for an example.

To read the JSON, you would then need to read from STDIN and not $_POST as per this answer/

score 0 · Answer 3 · edited Oct 07 '15 at 20:24

0

You can read properties of objects directly in $POST var, like this:

$_POST['news_data'] and $_POST['news_date']

You can check the post vars through the developer tools of the browser, in network tab.

edited Oct 07 '15 at 20:24

Mogsdad

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answered Mar 05 '15 at 14:23

Juan de Parras

768
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18

Few mistakes but finally got there. Wanted to vote for your answer but I need reputation to be 15. Thank anyway. – Robert Marczak Mar 07 '15 at 18:39

score 0 · Answer 4 · answered Oct 07 '15 at 21:14

The dataType property of the $.post options specifies the format of data you expect to receive from the server as a response, not the format of the data you send to the server. If you send data by the method POST - just like you do, if you use $.post - there is no need to call $aRequest = json_decode($_POST); on the serverside. The data will be available as a plain PHP array.

If you just want to get the news_data field as a response from the server, your serverside script should look something like this:

<?php
header('Content-Type: application/json');
$post = $_POST;
echo json_encode($post['news_data']);
?>

Notice, that you should check for the key news_data whether it is set.

Reading json object sent via ajax in php file

4 Answers4