[HxInputBase] Re-evaluate the automatic creation of an EditContext when none is found

[hakenr]

Blazor itself used to require explicit EditContext for input-components to work.
We implemented automatic creation of wrapping EditContext (cascading value) when we detected there is no EditContext used.
This worked pretty well!

It seems Blazor itself does not require EditContext for input-components any more.
And we found first scenario where the auto-created EditContext does bring some troubles:

• TP2 project (ImportSettingsUpdateEmployeesGrid)
• HxInputCheckbox used inside Telerik Grid
• The column Template contains checkbox (always visible, disabled, used to present the true/false value)
• When the grid switches to in-place editing mode (the column itself is set as non-editable), Telerik seems to add wrapping EditContext for that
• Which causes System.InvalidOperationException: Havit.Blazor.Components.Web.Bootstrap.HxCheckbox does not support changing the EditContext dynamically. coming from https://github.com/dotnet/aspnetcore/blob/e0ee9e981e4c90e78a31b36e41aecd9144119c77/src/Components/Web/src/Forms/InputBase.cs#L256-L265

Do we still need to generate the EditContext? Can we drop this feature as Blazor itself handles the scenario?
cc @jirikanda

[jirikanda]

It looks custom creation of EditContext is not needed anymore. See this commit.

[jirikanda]

But be very carefully because the EditContext instance (cascaded or auto-created) is used for component communication like HxValidationMessage. It there is no communication there is no message like parsing error etc.
EditContext is also expected in other internal component implementations (ie. HxInputDateRangeInternal). It is easy to make EditContext not-required but then it is lost communication HxInputDateRangeInternal -> HxInputDateRange -> HxValidationMessage (to be precise HxInputDateRangeInternal -> EditContext -> HxValidationMessage).
I guess, without autocreated edit context (at least) parsing error messages without EditContext will disappear.