[SLING-3715] Sling Models: Support for class-based dependency injection

• Type: Improvement
• Status: Resolved
• Priority: Minor
• Resolution: Fixed
• Fix Version/s: Sling Models API 1.1.0, Sling Models Implementation 1.1.0
• Component/s: Extensions
• Labels: models
• Assignee: Justin Edelson
• Reporter: Stefan Seifert
• Created: 30/Jun/14 20:24
• Updated: 25/Aug/14 08:13
• Resolved: 24/Aug/14 19:13

Description

Currently Sling Models dependency injection is primary based on parameter name-based injection, and not on class-based injection (the latter is more common in Spring and comparable frameworks).

here is Justins opinion on this topic (from the mailing list) and why he prefers name-based injection:

Hi Stefan,
The big problem IMHO with injecting by class vs. name is that by class
is too ambigious in many cases. For example, in AEM, it is relatively
common to want to inject a Page object, but in fact there are two
different page objects which come into play (currentPage and
resourcePage) and getting the wrong one could be highly problematic.
You are correct that things like the request and response could
presumably be injected by class rather than by name, but the question
then becomes how do we judge these cases? In my opinion, the bindings
names are sensible. I personally don't find myself wanting to write
this very often:

@Inject
private SlingHttpServletRequest somenameOtherThanRequest;

[...]
Regards,
Justin

Issue Links

• is related to: SLING-3716 Sling Models: Add support for constructor dependency injection