PHP json_encode not returning valid json

Question

I am running a Debian box with PHP v5.2.17. I am trying to get around the cross-domain issue with an XML file and am using this got to fetch any xml and return json:

<?php
header('content-type: application/json; charset=utf-8');

if( strlen($_GET["feed"]) >= 13 ) {
  $xml = file_get_contents(urldecode($_GET["feed"]));
  if($xml) {
    $data = @simplexml_load_string($xml, "SimpleXMLElement", LIBXML_NOCDATA);
    $json = json_encode($data);

    echo isset($_GET["callback"]) ? "{$_GET[’callback’]}($json)" : $json;
  }
}
?>

The problem is, its not returning valid json to jquery.. The start character is "(" and the end is ")" where jquery wants "[" as the start and "]" as the end. I've taken the output and used several online validation tools to check it..

Is there a way I can change these characters prior to sending back or pass json_encode options?

does it work if you remove the header('content-type: application/json; charset=utf-8'); part? I've never had a problem with json_encode() and I've never set a header like that either, but perhaps I should be. — ianbarker
– ianbarker, Commented Jun 29, 2011 at 10:47
With ( and ) You don't actually mean those in "{$_GET[’callback’]}($json)"? If yes, just remove them there? Otherwise I would be very suprised to find json_encode returning a value with enclosing parenthesis. — Yoshi
– Yoshi, Commented Jun 29, 2011 at 10:49
your question title is not true. json_encode() does return valid JSON, even with SimpleXML objects; the output passes any JSON validator and you can sucessfully json_decode() it. The actual problem has already been highlighted by several answer. — Álvaro González
– Álvaro González, Commented Jun 29, 2011 at 10:58

Berry Langerak · Accepted Answer · 2011-06-29 10:48:19Z

1

You could change json_encode($data) to json_encode(array($data)) if it expects an array (like you're saying):

$json = json_encode(array($data));

EDIT: Also, I believe the SimpleXml call will result in a bunch of SimpleXmlElements, perhaps json_encode then thinks it should be objects, instead of arrays? Perhaps casting to an array will yield the correct results.

answered Jun 29, 2011 at 10:48

Berry Langerak

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Community · Accepted Answer · 2023-11-17 19:32:19Z

1

You cannot json_encode() SimpleXMLElements (that's the type that is returned by simplexml_load_string(). You have to convert the data from the XML file into some native PHP type (most likely an array).

SORRY that's wrong. json_encode() can in fact encode SimpleXMLElements (at least on my PHP version 5.3.4). So if your client-side code expects an array you must wrap your $data in an array:

$json = json_encode(array($data));

edited Nov 17, 2023 at 19:32

CommunityBot

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answered Jun 29, 2011 at 10:50

Stefan Gehrig

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1 Comment

Gui Over a year ago

I don't understand why an array created by iterator_to_array() also needs to be converted to array in order to be a valid array for json_encode

Rukmi Patel · Accepted Answer · 2011-06-29 10:57:25Z

0

We can use json_encode() function most probably on array. so you first take XML content into PHP array and then apply json_encode().I think this will solve your problem..

answered Jun 29, 2011 at 10:57

Rukmi Patel

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Karolis · Accepted Answer · 2011-06-29 11:23:31Z

0

It seems that you are sending an empty callback parameter or something, but the callback parameter in jQuery must look exactly like this: callback=?

answered Jun 29, 2011 at 11:23

Karolis

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