PHP Map $_POST data to object

Question

This is more of a best practice question than anything.

Let's say I have a form:

<form action="self.php" method="POST">
    <input type="text" name="aA" />
    <input type="text" name="aB" />
    <input type="text" name="aC" />
</form>

And a corresponding class in PHP:

class A
{
    public function getA(){
        return $this->a;
    }

    public function setA($a){
        $this->a = $a;
    }

    public function getB(){
        return $this->b;
    }

    public function setB($b){
        $this->b = $b;
    }

    public function getC(){
        return $this->c;
    }

    public function setC($c){
        $this->c = $c;
    }

    private $a;
    private $b;
    private $c;
}

And somehow I manage to send the data from the form. Now, I need the form data transformed into an instance of A.

What I'm currently doing is the following:

abstract class AStrategy {
    public function doMapping(){
        $a = new A();
        if (isset($_POST['aA']) === true) {
            $a->setA($_POST['aA']);
        }
        ... (same for b and c)
        return $a; //A completely mapped object
    }
}

And I'm extremely aware this is pretty much bad practice (violating DRY).

What's the best practice to do this?
What if I have a complex object tree? What if I need to map related objects at the same time?
Who should do the mapping? Who should create the object and such?

Thank you beforehand.

would it be easier to do this: $post_obj = (object)$_POST; ?? — Aaron Gong, Sep 01 '13 at 06:40
No it would not. What would happen if I have data of several objects in one form? — Carlos Vergara, Sep 01 '13 at 06:40

Madara's Ghost · Accepted Answer · 2014-06-22T11:59:05.743

5

For simple objects, use a constructor:

public function __construct($a, $b, $c) {
    $this->a = $a;
    $this->b = $b;
    $this->c = $c;
}

For more complex objects, use a Mapper:

class AMapper {
    public function fetch(A $aObject) {}
}

edited Jun 22 '14 at 11:59

answered Sep 01 '13 at 06:39

Madara's Ghost

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I'm about to be convinced a mapper is what I need. But I'm just wondering, how do I tell the system what mapper do I want it to instance? By the way, I'm using a Front Controller, plus some few other model controllers if it helps. – Carlos Vergara Sep 01 '13 at 06:52
@user1231958: I usually go with a 1:1 ratio between Domain Objects and Mappers, each domain object has its own mapper. The mapps is created using a `DataMapperFactory` (which coexists side-by-side with the `DomainObjectFactory`). See the following answer for a very good, in-depth explanation: [How should a model be structured in MVC?](http://stackoverflow.com/a/5864000) – Madara's Ghost Sep 01 '13 at 06:56
It seems I've got a lot of rewriting to do. Thank you. – Carlos Vergara Sep 01 '13 at 07:10

PHP Map $_POST data to object

1 Answers1