Ease inheritance of ContentEntity datasource

The API is inconsistent.
getItemId() checks for the current config.
getItemIds() doesn’t.
So getItemId() is not suitable for deletions caused by config changes.

I consider that to be a bug.

My initial approach was to call getItemId() from getItemIds() but due to the different behaviour the tests failed.
But as this is a bigger issue I now introduced formatItemId() to have something small to overwrite.

drunken monkey → made their first commit to this issue’s fork.

Thanks a lot for suggesting this! The changes do make sense, great if this helps other modules provide their own entity-based datasources.
I had a few remarks and pushed the associated suggested changes. If you are happy with those, I’ll merge.

Looks good to me. I'll test the latest version of the patch on Monday.

I adjusted the code in search_api_default_content_deploy to the latest changes and it works :-)

Good to hear, thanks for testing!
Merged.