Question

I have some Json being returned from facebook which I’m then parsing in to an array using json _decode. The data ends up looking like this (this is just the snippet I’m interested in):

( [data] =>
     Array ( [0] => 
         Array ( 
             [id] => 1336269985867_10150465918473072 
             [from] => 
                 Array ( [name] => a name here 
                         [category] => Community 
                         [id] => 1336268295867 ) 
                         [message] => A message here

Now I’ve been able to iterate over this data and get what I need:

   $jsonDecoded = json_decode($json, true);
   $xmlOutput = '<?xml version="1.0"?><data><items>';
   foreach ($jsonDecoded as $e) {
       foreach ($e as $i) {
           $xmlOutput .= '<item><timestamp>' . $i['created_time'] . '</timestamp><title><![CDATA[ ' . $i['message'] .' ]]></title><link>' . $link . '</link><type>facebook</type></item>';
       }
   }

   $xmlOutput .= '</items></data>';

..up until now where I need to check on the from->id value.

I added this line in the second for each:

 foreach ($e as $i) {
     if($i['from']['id'] == '1336268295867') {

But this just gives me an error:

Fatal error: Cannot use string offset as an array in /Users/Desktop/Webs/php/getFeeds

Any ideas why? I’m sure this is the correct way to get at that value and in actual fact if I echo this out in my loop instead of doing the if statement above I get the value back:

$jsonDecoded = json_decode($json, true);
$xmlOutput = '<?xml version="1.0"?><data><items>';
foreach ($jsonDecoded as $e) {
    foreach ($e as $i) {
       echo $i['from']['id']  

This returns me all of the from->id values in the code returned from facebook and then following this I get the error:

133626829985867133626829985867133626829985867133626829985867195501239202133626829985867133626829985867133626829985867133626829985867133626829985867
Fatal error: Cannot use string offset as an array in /Users/Desktop/Webs/php/getFeeds.php on line 97

(line 97 is the echo line)

Answer 1

Your code makes a lot of assumptions about $i[‘from’][‘id’] and at least one of them is incorrect for at least one entry.
Let’s add some tests:

$jsonDecoded = json_decode($json, true);
$xmlOutput = '<?xml version="1.0"?><data><items>';
foreach ($jsonDecoded as $e) {
    if ( !is_array($e) ) {
        die('type($e)=='.gettype($e).'!=array');
    }
    foreach ($e as $i) {
        if ( !is_array($i) ) {
            die('type($i)=='.gettype($i).'!=array');
        }
        else if ( !array_key_exists('from', $i) ) {
            die('$i has no key "from"');
        }
        else if ( !is_array($i['from']) ) {
            die('type($i["from"])=='.gettype($i['from']).'!=array');
        }
        else if ( !array_key_exists('id', $i['from']) ) {
            var_dump($i);
            die('$i["from"] has no key "id"');
        }

        echo $i['from']['id'];
    }
}

And then you can add a var_dump(...) before the die(...) to take a look at the actual data.