Lazy Load and dependency problems

[augustohp]

When some configuration depends on another instance of the same configuration file, things don't go as one would expect:

The configuration

[pdo Pdo]
dsn      = [dsn]
username = [db_user]
password = [db_passwd]

[connectionParams]
pdo      = [pdo]
dbname   = [db_name]
user     = [db_user]
password = [db_passwd]
host     = [db_host]
driver   = [db_driver]

[config Doctrine\DBAL\Configuration]

[event Doctrine\Common\EventManager]

[cache Doctrine\Common\Cache\ArrayCache]

[config Doctrine\ORM\Tools\Setup]
createAnnotationMetadataConfiguration[] = [[orm_entity_dir], [orm_proxy_autogenerate]]

[dbal Doctrine\DBAL\DriverManager]
getConnection[] = [[connectionParams], [config], [event]]

[entityManager Doctrine\ORM\EntityManager]
create[] = [[dbal], [config], [event]] 

The test code

Now, suppose I want to test the given code... it is quite normal to inject my pdo instance like that

class DoctrineTest extends \PHPUnit_Framework_TestCase
{
    protected $container;

    public function setUp()
    {
        $this->container = new Container('config.ini');
        $pdo = new PDO('sqlite::memmory:');
        $pdo->setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION);
        $this->container->pdo = $pdo;
    }
 }

The problem

The $this->container->pdo is actually the instance I gave, but everything that uses it inside the config is binded to the old PDO instance (the one that the Instantiator will create).

[alganet]

I've researched this a little. It can double up our code base quickly, 'cause we need to track all Instantiators created from a particular Container instance. This means proxying Instantiator creation through a "parent" Container and update the references as the're set.

[alganet]

Also, in some cases is impossible to exchange the declared instance for other. For example, we cannot change an instance used in the constructor of another class.

[augustohp]

We can if the instance was not yet used. And that is what I am trying to do.

[augustohp]

@alganet: The fix is not working. I created a PHPT in a different branch so you can execute it. Merge it if you want, I created another phpt tests as well to use as examples of usage.

You can have a look to the specific test file here: https://github.com/Respect/Config/blob/phpt/tests/examples/injection-multiple.phpt

[alganet]

This is working for you, @augustohp?

[augustohp]

Not working, made a simple unit test to simulate the issue. Should I commit it? It will break travis, the test is not passing =(

[alganet]

Should work for instances, for primitives this is a little harder. Could be solved using &references the same way we solved primary key auto-increment feedback on Relational. I'll work on that when I have some time.

[alganet]

This is insane. I've tried adding references to the whole project but gave it up when I saw that references were impossible for string substitutions: date = "[day]/[month]/[year]" for example.

I've thought on another approach. We currently have a single step for loading/interpreting in the constructor. If we change this to only load on the constructor then interpret everything on the first __get/getItem, this issue should be solved. As long as the user doesn't change anything after the first getItem. This works even for the day/month/year sample above. Not in the mood fo implementing this now though.

This issue doesn't exists for objects, just scalars. Another approach would be convert any scalars to object. I dislike this very much.

[augustohp]

+1 for the two step solution on loading and interpreting the INI file. I will see how can I implement it.

[nickl-]

Solved test case and added support for instances in the same fashion see #26

[augustohp]

:+1: