codeigniter correct way to check if libraries/helper/core files is loaded

Question

i'm using codeigniter 2.

Appreciate if someone could show the correct way to check if the following files :
- library file is loaded?
- helper file is loaded?
- config file is loaded?
- model file is loaded?
- third_party file is loaded?

regards

Solution 1

You can use the native PHP function class_exists() to determine if the class has been defined, before calling it. In same regard, using method_exists() will check if class method exists.

Since helpers are collection of function, not methods, checking can be done using function_exists().

if (class_exists('Library')) 
{
    $this->library->myMethod();
}

For further info please refer to

http://php.net/manual/en/function.class-exists.php.

http://us.php.net/manual/en/function.method-exists.php

Solution 2

You don't have to check, you just load them wherever you need to be sure to have them.

Using CI's Load library ($this->load->[library|model|helper]) will always load it just once. You can see this if you turn on your debug logging.

Solution 3

this is codeigniter method to check the loaded libraries.

//If the library is not loaded, Codeigniter will return FALSE
if(!$this->load->is_loaded('session'))
{
     $this->load->library('session');
} 

Solution 4

Once loaded your instance is store on the controller, so to check if a model has been loaded :

if (isset($this->my_model))

Where $this is your controller.

Solution 5

The best way to do this is using Codeigniter's Loader Class. The Loader aka load has an inbuilt method is_loaded. is_loaded method checks if a class has already been loaded or not.

If the class has not been loaded then is_loaded returns FALSE, otherwise it returns property name.

Example:

$this->load->library('table');
$this->load->is_loaded('table'); //Returns 'table'
$this->load->is_loaded('blabla_library'); //Returns FALSE

View more solutions

Comments

[Hrvoje Golcic]

Are you sure about this? I include session library several times, the used memory raise significantly, I just tested it out. Codeigniter bug?

[minboost]

Look at Loader.php and search for 'Second attempt ignored' (NOTE: if you supply custom names, it will create a new instance).

[Hrvoje Golcic]

You are right, Codeigniter way is the most efficient way, I did a little benchmark

[Hrvoje Golcic]

This is correct way to check but if the reason for checking is to include the library then do not use this. I have made a little benchmark that proves the default Codigniter way of loading libraries is the best way. Look here: stackoverflow.com/questions/19630019/…

[Hrvoje Golcic]

This is correct answer to the question, here is a benchmark: stackoverflow.com/questions/19630019/…