codeigniter libraries dependancies - php

Question

Im trying to pass objects between classes in code igniter and am currently failing. What am I doing wrong. Let me strt showing the pure.php version
Errors.php
<?php
class Errors
{
public function __construct(){}
public function setError($msg){}
}
OtherClass.php
<?php
class OtherClass
{
public function __construct(Errors $errorObject) {}
public function someMethod() {}
}
Then in my main controller..
Controller.php
<?php
class Main
{
public function __construct()
{
$this->errors = new Errors;
$this->other = new OtherClass($this->errors);
}
}
By doing this. I can add errors as I go to my error Object, across any objects i instantiate from the Main controller.
Now my code igniter version looks like this
/library/Errors.php
<?php
class Errors
{
public function __construct(){}
public function setError($msg){}
}
/library/OtherClass.php
<?php
class OtherClass
{
public function __construct(Errors $errorObject) {}
public function someMethod() {}
}
Then in my main controller..
Controller.php
<?php
class Main extends CI_Controller
{
public function __construct()
{
$this->load->library('Errors');
$this->load->library('OtherClass',$this->errors);
}
}
When I do this I get an error in my OtherClass saying that $errorObject is not an instance of Errors. Why is the object not being passed?

Answer 1

The problem is with $this->load->library which is defined like this.
public function library($library, $params = NULL, $object_name = NULL)
$params is expected to be an array. If it is not then the $params is set to NULL.
To get around this requires a bunch of monkey biz.
class Errors is unchanged but class OtherClass needs to be changed to...
class OtherClass
{
public function __construct($errorObject)
{
var_dump($errorObject[0]); //so we can prove it got passed
}
public function someMethod(){}
}
Note the removal of the type hint Error from the constructor declaration. Also, we access index 0 of the argument. The reason lies in what happens at the controller.
function __construct()
{
parent::__construct();
$this->load->library('Errors');
$this->load->library('OtherClass', [$this->errors]);
}
We have to put $this->error in an array so that load->library() won't mess with it.
The alternative is to not use "The CodeIgniter Way" and use good old fashion `new' instead. The controller then is...
function __construct()
{
parent::__construct();
$this->load->library('Errors');
$this->other = new OtherClass($this->errors);
}
And other class reverts to...
class OtherClass
{
public function __construct(Errors $errorObject)
{
var_dump($errorObject);
}
public function someMethod(){}
}
Now the problem is that without adding an autoloader to the system you wind up with
Fatal error: Class 'OtherClass' not found in ...
This LINK goes to a page that talks about the various ways to add an autoloader to CI. I know this has been answered on SO too. But I'm failing to find it at the moment.