Dependency Injection/Service Location
Dependency Injection/Service Location
The following example is a bit lengthy, but explains why use service location and dependency injection. First, let’s pretend we are developing a component called SomeComponent. This performs a task that is not important now. Our component has some dependency that is a connection to a database.
In this first example, the connection is created inside the component. This approach is impractical; due to the fact we cannot change the connection parameters or the type of database system because the component only works as created.
class SomeComponent
{
/**
* The instantiation of the connection is hardcoded inside
* the component, therefore it's difficult replace it externally
* or change its behavior
*/
public function someDbTask()
{
$connection = new Connection(array(
"host" => "localhos
