[RESOLVED] PHP 5 Object issue?

reeksy

Hi,

I’m unsure if this is a bug with PHP or not?

The following won’t work:

define(FIELD_NAME,’my_title’); 

// Query database and return results as an object 
print $result->FIELD_NAME;

But this script will:

define(FIELD_NAME,’my_title’); 

// Query database and return results as an array 
print $result[FIELD_NAME];

Does anyone know why the first example won’t work? This is particularly frustrating as I auto assign posted form variables to an object. However I can’t access the objects within my class like so:

$this->FIELD_NAME;

Thanks

Jon

Installer

My guess: The result object is automatically created from an array as an instance of the built-in class stdClass. Constants are not confined in scope, so it's not a property of the object and referencing as if it were doesn't work, as you've seen. The same, more or less, goes for "this".

By the way, constants should be defined like this:

define('FIELD_NAME', 'my_title');

Not using the quotes could bite you someday, unexpectedly and in a hard-to-debug way if you keep developing with the notice error level off.

reeksy

Ok thanks! I better start defining the constants correctly.

Incidently, nomatter how you define an constant, you cannot use it with an object. The example below will not work:

define('FIELD_NAME','my_field');

$item->GetList();
while ($row = $item->db->FetchObject()){
     print 'Item name: ' . $row->ITEM_NAME . '<br />';
}

Installer

...nomatter how you define an constant, you cannot use it with an object.

I know. That's what I said. 🙂

reeksy

Whoops! Sorry – I really should pay more attention!

Since you’ve mentioned that I wasn’t defining my constants correctly I’ve switched my PHP configuration to display all errors and warnings. Luckily I haven’t taken this project too far so I’m down to just three warnings now! I’m glad you mentioned that – could have saved me a lot of time in the future!

The warnings I’m getting are where I’m trying to define a session name. I’m defining the session name within a class so I’m using the following:

$_SESSION[$this->sessionName] = 'My Value';

I’m getting a warning wherever I try to access/set the session using the class property (as above). Is this the same problem as we’ve just discussed? Is it impossible to define a session in the manor in which I’m trying?!

Sorry if I’m being a numpty with this one!

reeksy

Resolved. It wasn't the accessing or setting.

Installer

$_SESSION[$this->sessionName] = 'My Value';

Since $_SESSION is a superglobal, it just plain doesn't make sense to try to associate it with an inside-the-class-definition-only object.

I’m down to just three warnings now

See? Progress already. 🙂

reeksy

Installer wrote:
Since $_SESSION is a superglobal, it just plain doesn't make sense to try to associate it with an inside-the-class-definition-only object.

I disagree. I use a login class where I set the session name in the constructor. Then all I have to do to see if user is logged in or not is use my authentication method. The method checks to see if the session has a value (the user ID) assigned to it or not. If it does is passes, if not it redirects the user.

# Authenticate client 
	$client->Authenticate();

I don’t see why that doesn’t make sense?

Installer

I disagree. I use a login class where I set the session name in the constructor. Then all I have to do to see if user is logged in or not is use my authentication method. The method checks to see if the session has a value (the user ID) assigned to it or not. If it does is passes, if not it redirects the user.PHP Code:

Authenticate client

$client->Authenticate();
I don’t see why that doesn’t make sense?

I didn't say that didn't make sense (as you hadn't even posted it yet). It does make sense.

I was talking about this, and nothing else, in light of $SESSION being a superglobal:

$_SESSION[$this->sessionName] = 'My Value';

But I was wrong. It does make sense, in light of how you want to use it; it just doesn't work, apparently.