Is it possible to dynamically extend a model in Codeigniter?

Question

my models in CI are set up so that they load "sub"-models whenever they need certain functions. In order to keep my code as accessible and clean as possible, I want those submodels to extend the model they are called to.

So if I have two models:

<?php

class Mymodel extends Model
{



}

And:

<?php

class Submodel extends Model
{

    function test() { do something.. }

}

Then I need to, somehow, be able get the submodel to extend mymodel, so that I can do something like $this->mymodel->test(). It doesn't have to be mymodel that submodel extends, it could be any model. Any ideas?

Thanks for your time.

Answer 1

You have an incorrect understanding of inheritance between classes.

Inheritance only flows one way, Down.

if Myodel extends Submodel your $this->mymodel->test() would work, but it does not make sense as sub (child) objects are suppose to inherit from parent objects, not the other way around.

As an analogy, you wouldn't look at a child and tell the parent, "You look just like your child", because it is the child that is a part representation of the parent.

you need to take the word extends very literally, you are literally 'extending' the functionality of the parent.

===================

One way i believe you could accomplish this is to create ghost functions that simply load the proper model and call that models function (though I do not recommend this as it could get very confusing for debugging.

per your example

<?php

class Mymodel extends Model
{

    function test() {
        $this->load->model('submodel');
        $this->submodel->test();
    }

}

Submodel

<?php

class Submodel extends Model
{

    function test() { do something.. }

}

BUT again, if you are going for clean code, this is NOT the way to go, try and observe inheritance, and design your data with that in mind.

Answer 2

You can create utility model which may extends codeigniter's model and then all your models can extend that utility model. The methods you are going to add to the utility model will be available to all it's child classes aka your models.

How can you call a method which your class does not have or does not inherit from any other classes? Looking at your code, there is no relationship in your classes between Mymodel and Submodel.