But not only application components can be configured from the main configuration file.
I do a lot of "feature modeling" - that is, application components that are designed to be extended with additional features, in the form of components and behaviors, and I configure all of these from the main configuration file.
As an example, here’s the configuration for my shop component in an application I’m currently working on:
'summary' => 'ShopSummary',
'products' => 'GShopComputedSummary',
'promotions' => 'ShopComputedPromotion',
'discount' => 'ShopComputedDiscount',
'subtotal' => 'GShopComputedSubtotal',
'tax' => 'ShopComputedTax',
'shipping' => 'ShopComputedShipping',
'total' => 'GShopComputedTotal',
In my shop component, product features and computed fields are behaviors and components attached to the main shop application component. The shopping cart and order summary generator are also components, which means I can extend or replace them when I use the shop component in different applications.
The behaviors and components are created using calls to Yii::createComponent(), which is very practical, because it’ll handle a string (a simple class name) or an array (more detailed configuration) and I don’t have to manually check or handle these different levels of configuration everywhere.
But when I create (for example) features, I have to manually initialize them after I create them - and the pattern I follow, in almost any case, is identical to that of CApplicationComponent.
Note that __construct() will not work, because __construct() happens before Yii::createComponent() has a chance to initialize the component’s attributes.
Perhaps what I really need is actually closer to CModule than CApplicationComponent. Due to the size and complexity of CModule, I guess I figured maybe it was too much for what I needed. But perhaps my application component should actually have been a module, and my components should have been application-components.
I need to ponder this more deeply…