Flutter firebase get a field from document

Question

I'm trying to get the message from a field in a collection. It is a read only data, i have modeled it like this

class SocialShare {
  final String message;
  SocialShare({
    this.message,
  });
  factory SocialShare.fromJson(Map<String, dynamic> json) {
    return SocialShare(
      message: json['message'],
    );
  }
}

I have a collection named 'Social Share and contains a doc with a single field called message..

Here is how i call it

class SocialShares {
  final CollectionReference _socialMessage =
      FirebaseFirestore.instance.collection('socialShare');

  Future<SocialShare> fetchsocial() {
    return _socialMessage.get().then((value) {
      return SocialShare.fromJson(value); // how can i call it
    });
  }
}

How can i get a that value from firebase

Solution

You can do fetchSocial async and await the result to return:

fetchSocial() async{
  var value = await _socialMessage.get();
  return SocialShare.fromJson(value);
}

then you have to call fetchSocial method with await or then where you need it.

await fetchSocial() or fetchSocial.then ...

Comments

[Febin Johnson]

I'm using to load this message to a share button. And how can i avoid the error 'QuerySnapshot' can't be assigned to the parameter type 'Map<String, dynamic>

[Jorge Vieira]

you are getting all documents on the collection, so you need to call some like SocialShare.fromJson(value.docs[0].data), but this way you will aways get the first document. guess you should pass the id of the document to get only it from the collection. like this FirebaseFirestore.instance.collection('socialShare').doc(ido‌​fthedocument)

[Febin Johnson]

can't i simply pass like this onPressed: () { Share.share(socialshares.fetchSocial()); },

[Jorge Vieira]

@FebinJohnson i think will not works like this cause are async calls to the server, so you need to make the call, wait the result and then pass to the share, i'm not sure but i think will not work directly.