Added BeforeChunk and AfterChunk events

[colq2]

1️⃣ Why should it be added? What are the benefits of this change?

This PR adds two new events: BeforeChunk and AfterChunk.
These are triggered when exporting in chunks. With this it is possible to

• showing the progress to the user
• estimate time for an export

Related issue: #3606

2️⃣ Does it contain multiple, unrelated changes? Please separate the PRs out.

No.

3️⃣ Does it include tests, if possible?

It includes tests, but I don't know if you are quite happy with it. The test should cover, that the events are called exactly for the number of chunks. For this purpose, groups are created in the callback and counted at the end. Unfortunately I couldn't put in a callback because it can't be serialized.

If you have a better idea, let me know. I'm happy to change it.

4️⃣ Any drawbacks? Possible breaking changes?

No breaking changes.

5️⃣ Mark the following tasks as done:

• Checked the codebase to ensure that your feature doesn't already exist.
• Take note of the contributing guidelines.
• Checked the pull requests to ensure that another person hasn't already submitted a fix.
• Added tests to ensure against regression.
• Updated the changelog

6️⃣ Thanks for contributing! 🙌
🙌

[patrickbrouwers]

Somehow this test seems to be failing in GH Actions, can you have a look?

[colq2]

Fixed it. Sorry, didn't saw the GH actions.

[patrickbrouwers]

Can you already draft up a PR to the docs as well? Thanks!

[colq2]

Sure, added it!
While creating the PR I hove noticed, that the new events couldn't be registered with the RegistersEventListeners concern. So I added another test and relevant code for it.

Another point I noticed is, that all other events have some sort of context / payload e.g Writer or Sheet. It could be helpful to also add a context into BeforeChunk and AfterChunk like the Writer or the AppendQueryToSheet.
What do you think?

[stale]

This bug report has been automatically closed because it has not had recent activity. If this is still an active bug, please comment to reopen. Thank you for your contributions.

[Djoul]

Hi, any reason to not merge this PR? it's a nice feature to have for all the people that want to handle the export progress. Thanks

[HristoAntov]

+1 on merging the PR. I see no other reason for closing than inactivity.
These events are really useful for tracking current status of big exports and currenly I've found no other way to do it. Thanks

[sebestenyb]

Can we reopen this? It is a very much missed feature.