The Bakery Everything CakePHP

Update 09-04-2007

Cake already has a configuration system, and it's really neat. You can put files in app/config, fill them with values and load them automagically. config::read(). This is however something different. This is db based, meaning your values are stored in the db.
Let's see how we can set it up and use it.
Download the component from: http://bakery.cakephp.org/articles/view/242
and save it as conf.php in your components' folder.

Create the DB tables

Alright, so the first thing we need to do is actually create the database tables

Download code
CREATE TABLE `configs` (
  `id` int(10) unsigned NOT NULL auto_increment,
  `config_category_id` int(10) unsigned NOT NULL,
  `key` varchar(50) NOT NULL,
  `value` varchar(50) NOT NULL,
  PRIMARY KEY  (`id`)
)


Download code
CREATE TABLE `config_categories` (
  `id` int(10) unsigned NOT NULL auto_increment,
  `name` varchar(50) NOT NULL,
  PRIMARY KEY  (`id`)
) 


I gave the key and value columns a length of 50, but you can choose whatever you want.

Create the associated models

Next, we create the associated models

Model Class:

Download code <?php 
class Config extends AppModel {
    
    var $name = "Config";
    
    var $belongsTo = array('ConfigCategory');
}
?>

Model Class:

Download code <?php 
class ConfigCategory extends AppModel {
    
    var $name = "ConfigCategory";
    
    var $hasMany = array('Config');
}
?>

In the controller

As with any component, if we want to use it, we need to include it in the controller's $components array.

Controller Class:

Download code <?php 
var $components = array('Conf');
?>

That's all we need, we can start using our component now.
insert some data in the db tables for testing, I'll assume you have created a conf category named 'app', and some configs values.

Usage

Retrieving values

To retrieve conf values, we have two methods, get and find.

Controller Class:

Download code <?php 
$fooVal = $this->Conf->get('app.foo');
$barVal = $this->Conf->find('bar');
$foo2Val = $this->Conf->get('app.foo2','defaultFoo');
$bar2Val = $this->Conf->find('bar2','defaultBar');
$fooAll = $this->Conf->find('foo.*');

$booleanFoo = $this->Conf->get('app.foo2',true,true);

?>

Simple, in the first one, we know that the key 'foo' belongs to the conf category 'app', so we specify the name of the category and the key.
In the second, we actually don't know which category the bar key belongs to, so we use the method find. beware though, if you have two keys with the same name, it will return the first one it finds.
In the third example we introduce a new parameter, the default value that should be returned if the key we're looking for doesn't exist.
Same thing with the forth example, but with find(). And in the fifth example we introduce a new parameter that if set to true will return true instead of 'true' and false instead of 'false', it's basically to deal with boolean values.
The last example shows the syntax for getting all values of a category.

Saving values

To save values to the db, we have a method named set.

function set($key,$val,$possibleValues = null,$addCat = false,$addKey = false)


the first parameter is the key of the form category.key, the second is the value, simple. The third is ( if set ) an array of possible values, it's basically a quick validation test, $val must be one of the values in $possibleValues. You can ignore that parameter by setting it to null and indeed it's the default behavior. There are two extra parameters that default to false.
If the category passed in doesn't exist and addCat is true, the category will actually be created.
If the key passed in doesn't exist and addKey is true, the Key will actually be created.

If there is an error, set returns false.

Controller Class:

Download code <?php 
//
$this->Conf->set('app.foo','Cake!');
// weee and bar will be created if they don't exist
$this->Conf->set('app.lang','php',array('php','python','ruby'));
$this->Conf->set('weee.bar','chocolat',null,'true','true');
?>

Also, there is setCat and setBatch, the first expects a cat name and a data array where the keys are the conf names and the values are the config values something like array('i_am_a_key'=>'i_am_a_value','aww'=>'wee')

setBatch expects an array where the keys are the category names, and the values are arrays like the one passed to setCat

Caching

A new important feature has been introduced which is caching. File caching to be more specific. This was added to minimize DB hits.
A word of warning though:
Caching is really problematic in the sense, you can't know if a value has changed in the db. Maybe another user that has write access changed it and you still have the old value. There is no efficient way of detecting change. Looping through all the values in the db is just a no-no.
So, you shouldn't really change values through other interfaces than the conf component because, set() clears the cache. If you do, clear the cache manually using $this->Conf->clearCache().

The cache file is stored in app/tmp/persistent/conf.component.data.php you can change the name in the component.

Using the component in beforeFilter

Because of how components work, you can't use this component in beforeFilter. The reason is that Conf uses the startup() method to uh-huh startup. This method however is called by Cake after beforeFilter and before the current action. So as you guessed the component has not been initialized yet when beforeFilter is called and thus can't be used.
I LIE I LIE!!1 Well since the version 0.9.1 of the component, you can use the component in beforeFilter, provided you call startup() manually. I added logic so startup is not called twice by Cake.

Controller Class:

Download code <?php 
function beforeFilter()
{
  $this->Conf->startup(&$this);
  // call the component's methods ..
}
?>


That's it, have fun with this simple component, and as usual comments are welcome.