<p>I am writing a webapp using CodeIgniter that requires authentication. I created a model which handles all my authentication. However, I can't find a way to access this authentication model from inside another model. Is there a way to access a model from inside another mode, or a better way to handle authentication inside CodeIgniter?</p>

In general, you don't want to create objects inside an object. That's a bad habit, instead, write a clear API and inject a model into your model.
```
```
<?php
// in your controller
$model1 = new Model1();
$model2 = new Model2();
$model2->setWhatever($model1);
?>
```
```