Shared physical file provider with base directory as root

[mapogolions]

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Issue Details

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Author:	mapogolions
Assignees:	-
Labels:	area-Extensions-Configuration
Milestone:	-

[eerhardt]

I'm not certain this is a valid change. Thinking about #63540, the PhysicalFileProvider is IDisposable. Sticking it in the builder.Properties means people may be able to get at it after it has been disposed.

Can you add a reasoning/scenario (maybe in an issue?) for why this change is necessary?

[mapogolions]

As I understand from code, the Properties field of the IConfigurationBuilder instance is used like a temporary bag to store some shared data that can be used during construction the IConfiguration . Sticking the PhysicalFileProvider in the Properties of the ConfigurationBuilder also happens in case when we use another extension method the SetBasePath. Could you please explain to me what the difference between these cases? I just thought it would be great to create and use only one PhysicalFileProvider
At the moment, each configuration source calls EnsureDefaults and create own file provider with base directory as root. If we create shared physical file provider then lines of code below will have the same semantic

var builder = new ConfigurationBuilder().AddJson().AddIni().AddAnotherFile()...Build()
var builder = new ConfigurationBuilder().SetBasePath(AppContext.BaseDirectory).AddJson().AddInit().AddAnotherFIle()...Build()

[eerhardt]

Could you please explain to me what the difference between these cases?

The difference is that calling SetBasePath is an explicit action to stick the file provider into the Properties collection. You can use a single IConfigurationBuilder to build multiple configurations.

If someone disposed the PhysicalFileProvider while it was being held on to the ICollectionBuilder, you can get an ObjectDisposedException if you tried using the ICollectionBuilder again. It should be an explicit action to cache the file provider into the ICollectionBuilder.