This change removes reflection from validator providers, and instead
relies on cached metadata in in the modelmetadata.
In general this means that our MVPs don't need to cache anything, they
just look at the metadata and create what they need.
In the case of data-annotations, we update the model details provider to
add validation attributes to the modelmetadata. This would allow someone
to replace the DataAnnotationsValidatorProvider, but still use the
metadata in these attributes.
The change to the IModelValidatorProvider api (to use a context) is
intended to minimize allocations. Currently each validator provider needs
to return a list so you end up with N+1 lists (N validators + a final list
to compine them all). This change will let us just create the final list
(and a small context object). This is a very very high traffic API so it
seemed worth doing.
There's also some general massaging of namespaces and file locations.
Separates the MMP into two phases:
1). Creation of the ModelMetadata, discovery of properties and attributes
(reflection) is part of the MMP
2). Lookup of details based on attributes is now part of another phase,
and has its results cached.
Users can now implements and register an IFooMetadataProvider to customize
a single aspect of metadata (see how data annotations does it).
This also fixes#1503.
Currently all model binders except mutable object binder are independent of validation code. The mutable object binder which needs to do some validation ( for scenarios involving [BindRequired] and [BindNever]).
We would be going with an approach where required validaiton happens in input formatters and model binders.
This is needed as validation for value types can best be done at creation time.
Followup PRs:
Introduce support for skipping validation (and not binding) for a particular property/type etc.
This is a major refactor of how IBinderMetadata interacts with model
binders and value providers. We're doing this to support better
extensibility for metadata in ApiExplorer.
You'll notice a bunch of deleted code in DefaultApiDescriptionProvider
that maps metadata marker interfaces to a fixed list of Api sources. This
is replaced now with IBindingSourceMetadata - which also replaces the
hierarchy of marker interfaces. Now user code can create an arbitrary
binding source and have a consistent API for model-binders,
value-providers and full-visibility in ApiExplorer as
well.
Additonally, there's some error checking in place that better enforces the
constraints we already have in the system. IE you can't create a 'greedy'
model binder that uses value-provider data.
Two additional enhancements are planned for followup PRs:
1. Add a BindingSource property to model-metadata. This will remove some
duplication, but I want to delay it because it would touch another 10 or
so files.
2. Add an extensibility interface for our 'special' model binders like the
file binder so these can show up in ApiExplorer as well.
This is a new filter stage that surrounds the existing model binding,
action, and result parts of the pipeline. Resource Filters run after
Authorization Filters.
The other major change is to support one of the primary scenarios for
Resource Filters. We want a filter to be able to modify the inputs the
model binding (formatters, model binders, value providers, etc) -- this
means that those changes need to be held on a context object and preserved
so that they can be used in the controller.
So, IActionBindingContextProvider is removed - the ActionBindingContext
will be created by the invoker. For now it will be part of the action
context.
Pranav K
Ryan Nowak
Kirthi Krishnamraju
N. Taylor Mullen
Harsh Gupta
David Fowler