Injection info
Reflection allows discovery of metadata for all kinds of elements in the system. Unity is introducing new design with ability to reflect on injected data
Legacy Implementation
Original design relied on resolver policies and delegates to provide injected values. This method does not provide any information about what is being injected to the container.
At runtime the container would call resolver method on the injected member to obtain the value and perform all kinds of magic to implement overrides and build pipelines. This design required a lot of runtime reflection and created unnecessary overhead.
Even constant values injected into registrations would still be retrieved via resolver calls and would only be available at resolution stage.
Injection Reflection
Unity is introducing a new method to query injected members about what data is injected. It allows to analyze injections at the pipeline build stage and eliminate unnecessary resolvers and expensive runtime reflection.
The injection member provides the following information:
Contract of the injected import- Is this import optional
- What kind of data it injects, if any
The injected data is categorized into the following:
- Resolver delegate (same old delegate as before)
- Value
- None
When resolver delegate is returned by the query, Unity performs the same song and dance as before. It will call the delegate and get the value.
If None is returned by the query, Unity resolves value from the container using the Contract injector requires.
Obviously, the Value just used as is and returned immediately without any overhead.
Injection info
Reflection allows discovery of metadata for all kinds of elements in the system. Unity is introducing new design with ability to reflect on injected data
Legacy Implementation
Original design relied on resolver policies and delegates to provide injected values. This method does not provide any information about what is being injected to the container.
At runtime the container would call resolver method on the injected member to obtain the value and perform all kinds of magic to implement overrides and build pipelines. This design required a lot of runtime reflection and created unnecessary overhead.
Even constant values injected into registrations would still be retrieved via resolver calls and would only be available at resolution stage.
Injection Reflection
Unity is introducing a new method to query injected members about what data is injected. It allows to analyze injections at the pipeline build stage and eliminate unnecessary resolvers and expensive runtime reflection.
The injection member provides the following information:
Contractof the injected importThe injected data is categorized into the following:
When
resolver delegateis returned by the query, Unity performs the same song and dance as before. It will call the delegate and get the value.If
Noneis returned by the query, Unity resolves value from the container using theContractinjector requires.Obviously, the
Valuejust used as is and returned immediately without any overhead.