Problem 10: UseDbScopeAttribute was replaced by InteractionScopeAttribute.

[kegor]

Problem #10:
InteractionScopeAttribute needs to be added.

Solution:
In this PR were added InteractionScopeAttribute and InteractionScopeMiddleware, using them (in the current iteration) we can return untouched response or Db.Scope(next)/new Transaction.Scope(new) depending on attribute mode.

Related task: #5.

Tests:

1. Reference to the updated Starcounter.Startup was added into HeadsOmni sub-modules: SignIn/UserAdmin/Products/Showroom/Blending.
2. In the HeadsOmni solution build.cake and setup.cs were changed to run only apps from p.1.
3. In the composition for the Product page was added input that shows Products.Product.Name value.
4. Were performed two checks with using [InteractionScope(InteractionScopeAttribute.InteractionScopeMode.AttachOrCreate)] (default) [InteractionScope(InteractionScopeAttribute.InteractionScopeMode.AlwaysCreate)] on the ProductPage, results on the screenshots below.

Screenshots:

[mtornwall]

Left some change requests and suggestions. Really nice work. Thanks for the thorough testing.

[mtornwall]

• Will the DbScope attribute still work?
• Do we use it anywhere?
  • If yes, can we mark it obsolete and implement its logic in InteractionScopeMiddleware?
  • If no, can we drop it?

[kegor]

@mtornwall the answers:

1. Before changing UseDbScope on InteractionScope attribute i made few searches:
   I found usage of the UseDbScope attribute in the 6 apps: https://github.com/search?q=org%3AStarcounter+UseDbScope&type=Code, but at the same time i found invocation of the AddDbScopeMiddleware (that registers related middleware IIUC) only in AssortmentManager: https://github.com/search?q=org%3AStarcounter+AddDbScopeMiddleware&type=Code (and in Starcounter.Startup itself).
2. So my plan was: simultaneously with replacing old attribute with new one make the replacement in these apps, and invoke method AddInteractionScopeMiddleware in all, to restore initial logic. This why i decided to add the case with returning just next() as it was in the old attribute (we are discussing this point above currently).

[mtornwall]

@kegor Sounds like a reasonable plan.

[mtornwall]

Note though, when you upgrade the Startup version used by the HeadsOmni apps (and others), we'll need to do the same for the Buildcraft apps that use it. I can take care of that if you tell me the version to upgrade to.

[kegor]

@mtornwall, seems like improvements by your comments were made, could we go further with merge or some new tests should be made, what do you think?

[mtornwall]

No need for a separate namespace to hold the enums.

[mtornwall]

This class should go in the same namespace as the Url attribute I think.

[kegor]

After discussion with @mtornwall i made following test:
Martin i did few steps:

1. Made local 0.8.0 version package of the Starcounter.Startup.
2. Pulled HeadsOmni master and tried build-all (with commented lines for MGen/DoctorM in build.cake), and got success.
3. Then updated Starcounter.Startup version in the VS package manager.
4. Removed all occurrences of the UseDbScopeAttribute in the HeadsOmni solution opened in the VS.
5. Made build-all/run-all/load-config and checked that after signing in, the pages of the BlendingEditor (randomly selected app) opening as usual.