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Máxima Alekz
Asked: 2020-06-30 06:25:34 +0800 CST 2020-06-30 06:25:34 +0800 CST

PHP - Functions | Instance Methods $var→func($args)→func2($args);

  • 772

I was wondering how I could do this type of functions, or rather how to create a class or whatever is required to be able to execute the functions in the following way:

$var->metodo1($args)->metodo2($args)->metodo3($args);

Under what I assume from the code above, is that the result of method1 is used by method2 and the result of it is used by method3 .

I don't know what that kind of organization is called, that's why I ask the question this way. I have seen very similar code in Laravel .

I don't know if I'm wrong, that's why I ask. I tried to google but didn't find anything.

php

3 Answers

  1. Best Answer

    The "arrows" refer to an instance method (the functions that an object can invoke when it is instantiated), when applying one after another each method invoked should return an object, with an example it may be better understood:

    class Foo() {

    public function devolverNumeroAlCuadrado($num) {
        return $num * $num;
    }

    public function otroMetodo($num) {
        echo "Cualquier cosa";
    }
}

$var= new Foo(); // Instancio el objeto

$var->devolverNumeroAlCuadrado(2)->otroMetodo(); // ERROR!

    It throws an error since since it devolverNumeroAlCuadrado()returns a number, when calling otroMetodo()we are saying something like this:

    4->otroMetodo();

    And number 4 doesn't have that method. Therefore, if we want to call otroMetodo()what the previous methods return, it will have to be the same instance:

    class Foo() {

    public function unMetodo() {
        // Hace algo
        return $this; // Retorna el objeto llamador
    }

    public function otroMetodo($num) {
        echo "Cualquier cosa";
    }
}

$obj1 = new Foo(); // Instancio el objeto

$obj1->unMetodo()->otroMetodo(); // AHORA SI!!!

    Another example using two different classes:

    class Foo() {

    public function unMetodo() {
        // Hace algo
        return $this; // Retorna el objeto llamador
    }

    public function otroMetodo($num) {
        return new Bar();
    }
}

class Bar() {
    public function metodoSalvaje() {
        echo "Soy un Bar!";
    }
}

$obj1 = new Foo(); // Instancio el objeto

$obj1->unMetodo()->otroMetodo()->metodoSalvaje();

    I hope I was clear and helpful!

    Cheers!

    • 6

  2. Just to add another point of view:

    You can also have a class chainer, which allows you to call methods like this:

    $prueba->foo()->bar()->fou();

    without having to modify the classes foo, bar, fou. In that case the test class instance will be created by the class Encadenadorlike so:

    $prueba = new Encadenador('Prueba');

    Ejemplo:Ver Demo

    <?php 

class Prueba 
{
    function foo(){ echo "FOO\n"; }
    function bar(){ echo "BAR\n"; }
    function fou(){ echo "FOU\n"; }
}



class Encadenador 
{
    private $instance = null;
    public function __construct()
    {
        $pars = func_get_args();
        $this->instance = is_object($obj=array_shift($pars))?$obj:new $obj($pars);
    }

    public function __call($name,$pars)
    {
        call_user_func_array([$this->instance,$name],$pars);
        return $this;
    }

}


$prueba = new Encadenador('Prueba');   
$prueba->foo()->bar()->fou();

?>

    Resultado:

    FOO
BAR
FOU
    • 3

  3. how's it going? It seems to me that what you want to do is chain methods. This is a widely used pattern, in which the return of each method in the class that you want to chain returns the instance of the class. For example:

    class miClase {

   public function metodo1($var1) {
      echo "Este es el metodo 1 y recibió ".$var1;      
      return $this; // <-- aca esta la magia

   } 

   public function metodo2($var2) {
      echo "Este es el metodo 2 y recibió ".$var2;
      return $this; // <-- aca esta la magia
   } 
}

    Then you do:

    $obj = new miClase();
$obj->metodo1("hola")->metodo2("mundo");

    Since method 1 returns the instance ($obj), it can be chained automatically with method2. It's as simple as that.

    Cheers!

    • 1