Thanks for the links Attila, do you have an alternative one to the http://higherorderlogic.com/2011/07/is-dependency-injection-like-facebook? It seems to be broken.
I also started to also think containers don't worth the effort, but I am still concerned with problems faced with hand wiring everything as Peter clearly exemplified, thanks for the excellent summary and exemplification Peter! And this is just a basic example. Imagine that the PeopleService also needs > other services for it's use, and those services need more services, and you > want to keep everything separated as much as possible... instantiation by > hand will simply not cut it This is exactly my concern! Sure, for small stuff that is not a problem, but what if you have a big app? Now, my experience with containers and Java may be shadowing my vision: people in Java community tend to use anemic model and to create gazzilions layers for even simple stuff, which make the wiring problem even worse. My experiments with a more OO approach and Smalltalk tells me one would need much less need of containers by using proper OO and a less verbose language, but I am not sure. Keep in mind however that relates primarily to using application > frameworks, where the framework mandates the control, and the framework is > the one calling you, and therefore it will also provide you with necessary > parts. After all you are not even creating PeopleService class, the > framework instantiates it for you and gives it to another services/classes > that needed it. This is true for IoC DI containers, but I don't think it applies for service locator, which, I think, could not be considered a framework approach. Actually, I think being a framework is the big problem of the of the former, since when I start to use an IoC container to create objects I got tied to it in a very basic and pervasive operation of an OO system: object creation. Suddenly everything must be created through the DI container, but that is not true for Service Locator. However I wouldn't be surprised if the liveness of Smalltalk/Pharo > environment eliminated some of the problems that DI is trying to solve. That is precisely what I wanted to know. It seems there are no DI counterpart in the Pharo/Smalltalk environment, ok, so what people do to to deal with the above mentioned problem? Hand wiring is suffice? Is there anything in the liveness of Smalltalk/Pharo that eliminates the need for it? People use simple Service Locator, or variations of it? cheers! Vitor On Wed, Jun 7, 2017 at 9:32 PM, Ben Coman <b...@openinworld.com> wrote: > > > On Tue, Jun 6, 2017 at 11:48 PM, Attila Magyar <m.magy...@gmail.com> > wrote: > >> I don't think using a DI container worth the effort. They add lots of >> complexities and solve very little. For some reason DI containers became >> very popular in the Java world, but if you take a look at other >> programming >> communities you'll realize that many people are perfectly happy without >> using these containers. Using DI and using a DI container is orthogonal. >> As >> you also said you can just pass dependencies to objects to achieve loose >> coupling. Yes, you have to do this manually but what's the big deal? We're >> talking about code with cyclomatic complexity of 1. Calling a constructor >> is >> not a problem that need to be solved. Using an external XML configuration >> to >> describe object wiring is the worst idea ever. >> >> Here is an article about using plain old object composition to do DI >> >> http://blog.davidpeterson.co.uk/2011/01/object-oriented-example.html >> >> Some more thoughts about the problems associated with DI containers: >> >> http://www.natpryce.com/articles/000783.html > > > I liked this... "the [Dependency Injection] pattern also used to be > called "third-party binding" or "third-party connect": some third party is > responsible for connecting an object satisfying the service requirements of > a component" > This makes the subject seem less esoteric. It reminds me of hearing that > the first (secret) task when doing a PhD is to invent new terms for common > ones, and base your writings on that. Perhaps its the same for consultants > and framework developers. ;P Or maybe everything seems esoteric until you > have experience with it and I've not done much with Java, certainly not big > applications. > > Thx Peter for your example and how you prior experience compares to Pharo. > > cheers -ben > > >> http://higherorderlogic.com/2011/07/is-dependency-injection-like-facebook >> >> >> >> -- >> View this message in context: http://forum.world.st/Wiring-o >> bjects-IoC-and-Service-Locator-tp4949280p4949720.html >> Sent from the Pharo Smalltalk Users mailing list archive at Nabble.com. >> >> >
