is_real
I was recently trying to loop through some objects and convert them to arrays so that I could encode them to json strings.
I was running into issues when an element of one of my objects was a SoapClient. As it turns out, json_encode() doesn't like any resources to be passed to it. My simple fix was to use is_resource() to determine whether or not the variable I was looking at was a resource.
I quickly realized that is_resource() returns false for two out of the 3 resources that are typically in a SoapClient object. If the resource type is 'Unknown' according to var_dump() and get_resource_type(), is_resource() doesn't think that the variable is a resource!
My work around for this was to use get_resource_type() instead of is_resource(), but that function throws an error if the variable you're checking isn't a resource.
So how are you supposed to know when a variable is a resource if is_resource() is unreliable, and get_resource_type() gives errors if you don't pass it a resource?
I ended up doing something like this:
<?php
function isResource ($possibleResource) { return !is_null(@get_resource_type($possibleResource)); }
?>
The @ operator suppresses the errors thrown by get_resource_type() so it returns null if $possibleResource isn't a resource.
I spent way too long trying to figure this stuff out, so I hope this comment helps someone out if they run into the same problem I did.
is_resource
(PHP 4, PHP 5)
is_resource — Détermine si une variable est une ressource
Liste de paramètres
- var
-
La variable à évaluer.
Valeurs de retour
Retourne TRUE si var est une ressource, FALSE autrement.
Exemples
Exemple #1 Exemple avec is_resource()
<?php
$db_link = @mysql_connect('localhost', 'mysql_user', 'mysql_pass');
if (!is_resource($db_link)) {
die('Connexion impossible : ' . mysql_error());
}
?>
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User Contributed Notes
is_resource
btleffler [AT] gmail [DOT] com
12-May-2011 01:55
tacomage at NOSPAM dot devilishly-deviant dot net
06-Aug-2004 06:10
Note that the use of is_resource isn't necessary in the example. mysql_connect (along with any other function that would return a resouce, I imagine) returns false on failure, so the same results could be obtained with:
<?php
$db_link = @mysql_connect('localhost', 'mysql_user', 'mysql_pass');
if (!$db_link) {
die('Can\'t connect : ' . mysql_error());
}
?>
Or even:
<?php
$db_link = @mysql_connect('localhost', 'mysql_user', 'mysql_pass')
or die('Can\'t connect : ' . mysql_error());
}
?>
You'd be more likely to use is_resource AFTER the initial conection, to make sure the variable you intend to use as a resource is, in fact, a connection resource. You might also use is_resource as a sanity-check prior to serializing an object, since resource variables can't be serialized.