php class call function within function - php

Question

Could someone help me understand how I can make functions within class methods, that would allow me to do things like this:
$class->send->activation_email()
I've seen many APIs do this, so I've tried:
class MyClass
{
public function send()
{
function activation_email()
{
echo "success!";
}
}
}
Undefined property: MyClass::$send

Answer 1

Consider:
class emailSender()
{
function activation_email()
{
if (mail($this->to, $this->subj, $this->body)) {
print $this->msg;
}
}
class MyClass
{
var $send;
function __construct()
{
$this->send=new emailSender();
$this->send->msg="success!";
}
}
$obj=new MyClass();
$obj->send->activation_email();

Answer 2

You probably want to an instance of another class within your class. Make a variable inside your class like this:
$this->otherclass = new Otherclass();
In this case, you can call functions from your other class the following way:
$myClass->otherclass->otherClassFunction()

Answer 3

Someone had answered but deleted the post. This is along the lines of what I was hoping for, and it works as expected:
class MyClass {
public function send(){
echo "Sending: ";
return $this;
}
public function activation_email(){
echo "activation email.";
}
}
$myClass = new MyClass();
$myClass->send()->activation_email();

Answer 4

What you are referring to (shame on no one for noticing this, for shame) is called "method chaining". A lot of big frameworks do this. Consider this example of use:
echo $obj->setName('Mike')->convertMtoN()->getName();
// Echoes "Nike"
Cool.
But here is how it works:
class Example {
private $name = '';
public function setName($name) {
$this->name = $name;
// We return the object, so you can call it again.
return $this;
}
public function convertMtoN() {
// Let's do Caps first
$this->name = str_replace("M", "N", $this->name);
// Then lowercase
$this->name = str_replace("m", "n", $this->name);
// We return the object, keep working
return $this;
}
public function getName() {
return $this->name;
}
}
$name = new Example;
echo $name->setName('Mike')->convertMtoN()->getName();
Essentially, for each method that does not implicitly return a value, you simply return the object, allowing you to continue chaining.
Awesome, right?
PHP rocks (now, I know it has its faults, but with HHVM and process forking, it basically rocks [dude, you will get there]).
You can play with this here:
https://ideone.com/fMcQ9u