[RFC] Deprecated Table columns.render return cell props and use `onCell` instead

📋 RFC

Summary

Use onCell instead of render return cell.props.

Basic example

    const columns = [{
      dataIndex: 'name',
--    render: (val) => ({
--      props: { colSpan: 2 },
--      children: val,
--    });
++    onCell: (record) => ({ colSpan: 2 });
    }];

Motivation

As #32979 mentioned. Table column mix props & node in one render function which cost additional perf calculation. And this will also makes row hover calculation no way to optimize. Since we already have onCell function and this is same logic as render.props, it’s reasonable to de-duplicate.

Detailed

To make this RFC done:

1. We need patch warning info in rc-table and suggest user move to onCell. Also keep origin span logic do not modified.
2. Move hover logic to onCell base which will speed up render perf

Drawbacks

No break of current usage. But get warning.

Adoption strategy

When finished dev will replace all demo to new usage.

[chillyistkult]

How to get value as parameter of onCell? As I understand only record is passed in onCell, for what would we need dataIndex then?

Seems like deprecating render while not fully support an alternative is not the best approach.

I am asking this because table performance is still horrible, because of the hover issue.

[VahanBeck]

How to get value as parameter of onCell? As I understand only record is passed in onCell, for what would we need dataIndex then?

Seems like deprecating render while not fully support an alternative is not the best approach.

I am asking this because table performance is still horrible, because of the hover issue.

Exactly! The value property is very useful, so i don’t think we will migrate to onCell until you have a suitable substitute to render