Clarify the relation between SQLiteContentProviderImpl and ExtendedSQLiteOpenHelper

[friedger]

This PR clarifies the need of SQLiteContentProviderImpl for an ExtendedSQLiteOpenHelper.

getDatabaseHelper is overwritten and returns the ExtendedSQLiteOpenHelper.

[stefanhoth]

Can one of the admins review this PR?

[frapontillo]

CI, please test this.

[frapontillo]

So this is basically moving the casting to another method that can be easily overridden.

[friedger]

And it forces sub classes to also use the ExtendedSQLiteOpenHelper.

[juankysoriano]

@friedger you mention that this fixes #57, correct me if I am wrong but seems that rather than fixing formalises the expected usage, right? The person opening that issue wanted to use his own SQLiteOpenHelper, your PR instead makes explicit the need for ExtendedSQLiteOpenHelper; am I right?

[blundell]

I agree with @juankysoriano

And it forces sub classes to also use the ExtendedSQLiteOpenHelper.

we don't want to force this do we? Rather we should get rid of the explicit cast and code that class to the interface

[friedger]

I have removed the reference to #57 . So, this does not fix it, but helps users to understand the implementation better until #57 is fixed.

[juankysoriano]

So, this does not fix it, but helps users to understand the implementation better until #57 is fixed.

Yeah, I think this is better than stating this fixes the issue. And also better that having the current side-effect.

The ideal solution to #57 will then be something along the lines of what @blundell suggests.

Leaving this to @blundell in case he has more comments, thanks for the contribution @friedger

[blundell]

If we merged this solution it would couple us tighter to the current implementation.

Right now it is an implicit cast that the public API doesn't know about. Merging this change would make the contract explicit but it would also mean a non backwards compatible change i.e. compile errors when people upgrade - then if we did the fix for #57 we would change the signatures back and people would again have a break in the API contract.

I don't think we should merge this change.

Sorry 👍