CODEWITHSUNDEEP
phpoopinheritance
Fractaliste
Fractaliste

Reputation: 5957

Inheritance - how to add child code in the middle of a parent method?

I've the following class (simplified here, and so not tested):

class FATHER {

    protected function getDatas() {
        $this->query = "SELECT * FROM somewhere WHERE year = ? AND id_smthg = ? ";
        $this->param = array($_GET['year'], $_SESSION['anId']);

        // if $this is a FATHER
        if (get_called_class() == get_class())
            DB::getDatas($this->query, $this->$params);
    }

}

class CHILD extends FATHER {

    protected function getDatas() {
        parent::getDatas();
        foreach ($this->conditions as $condition) {
            $this->query .= " AND $condition->name = ? ";
            $this->param .= array($condition->value);
        }

        DB::getDatas($this->query, $this->params);
    }

}

The child method just adds SQL conditions to the parent's query, and then execute the request. But the DB call is redundent, and requires an if statment into the parent method.

So I would like to know the recommended way to do it?

I imagine something like that, but I don't know how to do it:

class FATHER {

    protected function getDatas() {
        $this->query = "SELECT * FROM somewhere WHERE year = ? AND id_smthg = ? ";
        $this->param = array($_GET['year'], $_SESSION['anId']);

        // Make the child execution here

        DB::getDatas($this->query, $this->$params);
    }

}

Maybe it's impossible, or maybe there is a better design pattern to do it?

Upvotes: 0

Views: 91

Answers (1)

Dima
Dima

Reputation: 8652

You can use abstractions, that way you can override parent method with child code and it will be called

you can read about it here

abstract class AbstractClass
{
    // Force Extending class to define this method
    abstract protected function getValue();  //this kind of methods you should implement in child
    abstract protected function prefixValue($prefix);

    // Common method
    public function printOut() {
        print $this->getValue() . "\n";
   }

}

Upvotes: 2

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