How to get the trait name with namespace inside itself?

Question

I want to know if there is a way to get the traits namespace inside itself, I know that I can use self::class to get the classname, but inside a trait it gets the namespace of the class that is using the trait, I don't want to type it's name fixed like new ReflectionClass('trait')

Is there any function or const that can do this?

Answer 1

I'm a little bit confused by your question but if you need the fully qualified name from the trait then you may use __TRAIT__ magic constant and if you only need the namespace of the trait then you may use __NAMESPACE__. For example, declare a trait using a namespace:

namespace App\Http\Controllers\Traits;

trait Methods
{
    public function getNamespace()
    {
        // Get fully qualified name of the trait
        echo __TRAIT__; // App\Http\Controllers\Traits\Methods

        echo PHP_EOL;

        // Get namespace of the trait
        echo __NAMESPACE__; // App\Http\Controllers\Traits
    }
}

Now, declare a class using another namespace and use that trait inside this class:

namespace App\Http\Controllers;

use App\Http\Controllers\Traits\Methods;

class TraitController
{
    use Methods;

    public function index()
    {
        // Call the method declared in trait
        $this->getNamespace();
    }
}


(new TraitController)->index();

The predefined magic constants __TRAIT__ (since 5.4.0) and __NAMESPACE__ (since 5.3.0) is used so use which one is needed. Tested in php v-5.4.0. Check the demo here.

Also, if you want to get the fully qualified name of the trait from the class that is using it then you may use NameOfTheTrait::class (NameOfTheClass::class/NameOfTheInterface::class) but this is available since php v-5.5.

Also be careful when using self::class. The self::class will give the fully qualified name of the class where you've used it because the self always references the lexical scope (where it's physically used) since the scope of self is determined during the compile time so you may get unexpected results if you inherit a class where a self::class statement is used. In other words, if you call any static method from a child class then the calling context will be still the parent class if you use self in your parent class, in that case you need to use static instead of self. This is actually another topic so please read more on php manual about Late Static Binding.