How to encapsulate a file include?

Question

If I have a class that includes a file with a constant like so:

define("FOO", "bar");

Is there a way to make the class include the file with encapsulation so if I use the class somewhere that already has a FOO constant defined it won't break?

Answer 1

Create a static class and use constants would be the best way to encapsulate specific constants:

static class Constants
{
    const Name = 'foo';
    const Path = 'Bar';
}

And then use like so:

echo Constants::Name; //foo
echo Constants::Path; //bar

in regards to the precheck you can do

function _defined($key,$check_classes = false)
{
    if($check_classes)
    {
        foreach(get_declared_classes() as $class)
        {
            if(constant($class . '::' . $key) !== null)
            {
                return true;
            }
        }
    }
    if(!defined($key)) //global Scope
    {
        return true;
    }
}

Usage:

class a
{
    const bar = 'foo';
}

if(_defined('bar',true)) //This would be true because its within a
{
    //Blah
}

---

If your thinking of a situation like so

class a
{
    const b = '?';
}
class b
{
    const b = '?';
}

the constants are within the class scope so they would have no affect on one another !