Duplicating an item doesn't generate new ID

[henrikwirth]

Hi there, thanks for creating these widgets, I think NetlifyCMS is lacking behind with lots of things for sure.

I am using the ID Widget to generate unique IDs for collection items. Now the issue I am running into is that once I duplicate one of the items it copies the ID field too. Since it is supposed to be the unique identifier obviously this causes issues.

2 options i see:

1. Is there a way to add a regenerate directly once someone duplicates an item?
2. Is there a way to add a Regenerate Button next to the ID field to do this manually?

I'd be happy to help with a PR, but I since I never wrote a Widget I am not well aware of the possibilities.

[d4rekanguok]

Hi @henrikwirth, thanks for opening this issue!

It looks like there's a 'prepublish' event we can hook into to generate a uuid for a field. I think this could potentially solve this issue:
https://www.netlifycms.org/docs/beta-features/#registering-to-cms-events

This repo is quite outdated so I'm hesitate to dive back in, if you want to take a crack at setting something up (a new widget, or an update to this one) I'm happy to assist with any issues you might run into!

[henrikwirth]

I think I might have found a way. There is a newRecord: true on the data that is passed to the prePublish hook if the item is newly created/duplicated. If we check for that, we can trigger the generation of the ID right there instead of initially pre-populated.

[henrikwirth]

CMS.registerEventListener({
  name: "preSave",
  handler: ({ entry }) => {
    const data = entry.get("data");

    if (entry.get("newRecord")) {
      return data.set("id", "test-1234");
    }
  },
});

Not sure how we would access the Control Object to generate the ID according to the props. Any idea?

[d4rekanguok]

Currently the generate function is coded within the React component that drives the input:

netlify-cms-widgets/packages/widget-id/src/control.tsx

Lines 26 to 39 in 67ac5d4

	public generateId() {
	const { field, onChange } = this.props
	const usePrefix = field.get('prefix')
	const usePostfix = field.get('postfix')
	const useTimestamp = field.get('timestamp')
	const prefix = usePrefix ? usePrefix + '-' : ''
	const timestamp = useTimestamp ? Date.now() + '-' : ''
	const postfix = usePostfix ? '-' + usePostfix : ''
	const id = prefix + timestamp + shortid() + postfix
	onChange(id)
	}

I think it'd be good to extract it out into a util function & export it