Magic methods can be a lot of fun, as well as extremely powerful.

But PHP gives us even more magic in the form of magic constants.

PHP provides a large number of predefined constants to give us a little more magic.

These special constants both start and end with double underscores, and

are not case sensitive.

But, if we start changing the case all over the place,

it makes things very difficult to read.

You should write all constants in uppercase.

Magic constants can provide a lot of information.

Let's take a look at a few of the most useful in relation to objects.

Let's modify the to string method.

Instead of only displaying the recipe title,

let's give it a bit more information about the object itself.

The first magic constant we'll use is class.

Written __CLASS__.

This gives us the name of the class itself.

Let's use this in a message.

Let's also remove our call to the display recipe.

Now let's run our script.

Now we see that you are calling a recipe object with the title, My First Recipe.

Looks good so far.

Let's add a little more magic.

There are two constants that reference the file where the class is stored.

The first one is __FILE__.

This gives us the full path with the file name.

We can get just the file name by combining that with the function, basename.

We could use the function dir name with file as well to pull

only the directory path.

But we have another constant that you'll often see the __DIR__ or

directory constant.

This constant gives us the full path to the file without the file name.

I use __DIR__ often when I want to link to another file

within the same directory as this file.

It works even if this file is included in another file.

Let's add both of these to our message as well.

Next, let's show specific information about where in the class we are currently

looking.

__LINE__ will tell us the current line number in the file and

the __METHOD__ will tell us the name of the method we are using.

Let's add these as well.

Finally, let's show a list of the methods in case the user is looking for something.

This is another place where we use a function in combination with

a magic constant.

get_class_methods.

We then pass it the __CLASS__.

Now let's add this to our output.

Let's use the implode.

When we finish, we want to return the output.

Now we're ready to run our script again.

Wonderful, we have a lot of information about our object that we can use to update

the call to our object.

For example, I can look through the list of methods and

see the exact name of my getters and setters.

For security purposes,

you should not display the full directory path on a production server.

It can give hackers much more information than you want.

Let's add this two string method to our render class as well.

Then we'll be able to show the methods that are available.

Let's copy this.

And we'll go in to render.

We only want to say what methods are available.

But let's change this so it tells us which type of object we're using.

Now let's go back to our cookbook.

Since we don't have an object, we can just echo new Render.

And now let's run our code.

Great, we see the results of the render object as well.