feat(firestore): options to include document ID on valueChanges()

[mjastrzebowski]

Checklist

• Issue number for this PR: Proposal: Optionally return a document ID on valueChanges() when reading a single document #2109
• Docs included?: Yes
• Test units included?: Yes
• In a clean directory, yarn install, yarn test run successfully? Yes

Description

Continuation of #1976 - added idField option for document.valuChanges() to include the document ID on the emitted data payload. Updated documentation for this one and added some missing changes from the previous PR.

Code sample

documentRef.valueChanges({ idField: 'customID' }).subscribe()
// emits [ { customID: 'MrfFpRBfWLTd7LqiTt9u', ...data }, ... ]

[jamesdaniels]

LGTM, thanks! Will merge once ready to cut 5.3

[leolara]

This is very important feature, thank you

[leolara]

I think this does not work if you call it on a collection instead of a document

[leolara]

This is what I had to do to make it work on a collection. Perhaps there is better way, but this is my first week with rxjs:

readAll(): Observable<Listing[]> {
        return this.afs.collection<Listing>(COLLECTION_NAME).snapshotChanges().pipe(
            map((payloads) => {
                return payloads.map(({payload}) => {
                    return {
                        // tslint:disable-next-line:ban-types
                        ...payload.doc.data() as Object,
                        ...{id: payload.doc.id}
                    } as Listing;
                });
            })
        );
    }

[EdricChan03]

LGTM, thanks! Will merge once ready to cut 5.3

Are there any updates to this PR? It's been a while since release 5.3.

[jamesdaniels]

Whoops, meant to get this into 5.3 but working on 6 ate up all my time. Will get this into 6.1.

[kyleabens]

Can this be added to 6.0.4?

[jamesdaniels]

New API so had to wait for a minor, will aim to get this in today for rc.1.