Name spaces in php - php

Question

I am kind of confused about using name spaces in php,would try to explain using the problem I have with one of my project
I have a class under a namespace as
namespace BigBlueButton;
class BigBlueButton
{
public function createMeeting($createMeetingParams, $xml = '')
{
//some code
return new CreateMeetingResponse($xml);
}
}
I use it as
use \BigBlueButton;
$bbb = new BigBlueButton\BigBlueButton();
//then I try to reference the variable $bbb in a function but I can't
function easymeet_create_meeting($id) {
// $bbb = new BigBlueButton\BigBlueButton(); I don't want to create a new object here but reference the object I created above,something like this
$bbb=BigBlueButton\bbb;
}
But I can't seem to access the above variable i.e. $bbb , I tried global $bbb ,but $bbb doesn't seem to be in the global namespace, I understand I am trying to access a constant $bbb in the above code, but I showed it anyway to tell what I am trying to do

Answer 1

Namespacing does not extend to variables like that:
In the PHP world, namespaces are designed to solve two problems that
authors of libraries and applications encounter when creating
re-usable code elements such as classes or functions:
Name collisions between code you create, and internal PHP classes/functions/constants or third-party
classes/functions/constants.
Ability to alias (or shorten) Extra_Long_Names designed to alleviate the first problem, improving readability of source code.
http://php.net/manual/en/language.namespaces.rationale.php
Your class declaration is fine, but you've mis-used the use keyword as it should refer to specific classes, not a namespace.
use \BigBlueButton\BigBlueButton;
function easymeet_create_meeting($id, BigBlueButton $bbb) {
/* ... */
}
$bbb = new BigBlueButton();
$result = easymeet_create_meeting(1234, $bbb);
You'll notice that I've also moved $bbb into the function parameters because global state is the devil. It's also type-hinted because why not?
Better yet:
class BigBlueButton implements ButtonInterface {}
class BigRedButton implements ButtonInterface {}
And:
function easymeet_create_meeting($id, ButtonInterface $bbb) {}
$result[] = easymeet_create_meeting(1234, new BigBlueButton());
$result[] = easymeet_create_meeting(5678, new BigRedButton());
And now we're looking at the rudiments of Dependency Injection, which is a good habit to get into.

Answer 2

If I understand it right the problem is not with namespace.
As you said you could try using a global variable for example:
use \BigBlueButton;
global $bbb;
$bbb = new BigBlueButton\BigBlueButton();
function easymeet_create_meeting($id) {
global $bbb;
// you can use it
}
or you can send the variable to the function
function easymeet_create_meeting($id, $bbb) {
}
I do not know the entire problem, but you could also use a singleton design pattern in the class so you always get the same instance every time you use it.