Angular fire : get the keys,values from map in a document as an observable

Question

This is my firestore document . I want to get the list of comments to an observable, subscribe to that and iterate through the comments. How to do that using angular fire ? I am a beginner here so I would be much thankful to you if you could explain this in detail

Thank you !

Answer 1

On your component.ts file

doc: issue;
doc_comments: Array<string>;
ngOnInit() {
    db.collection('Agriculture_and_cropes').doc<issue>('doc_Id').valueChanges().subscribe(data => {
        this.doc = data;
        this.doc_comments = Array.from( data.comments.keys() );
    });
}

On your component.html

<ul *ngIf="doc_comments">
    <li *ngFor="let c of doc_comments">
        {{c}} : {{doc.comments[c]}}
    </li>
</ul>