Uri of RowReference

[dmfs]

In order to communicate the Uri of a newly inserted row, I want a mechanism to retrieve the Uri from a RowReference, if possible.

There are conditions under which a RowReference can't be expressed as a Uri, namely when the respective row has not been committed yet or when the TransactionContext of that transaction is not available. So we probably have to consider an Optional<Uri>.

This is similar to a "serialize"/"unserialize" mechanism for RowReferences to committed rows, because with RowUriReference you can easily create a RowReference from a Uri.

[dmfs]

Implementation idea.

We add another method to RowReference which returns an Optional<Uri>.

public interface RowReference<T>
{
    …
    /** Returns the Optional Uri of the row this refers to. */
    @NonNull 
    Optional<Uri> rowUri(@NonNull TransactionContext transactionContext);
}

Some RowReferences don't know their table Uri, so we'll also have to extend the Table interface like so:

public interface Table<T>
{
    …
    /** Returns the Uri of a row with the given row id*/
    @NonNull
    Uri rowUri(long id);
}