i want to read data from map inside array in flutter

Question

there is an array in every document which contains a map (list) of songs and i want to Stream (read) them here in this page but i get this error

type 'List<dynamic>' is not a subtype of type 'String'

body: StreamBuilder(
        stream: Firestore.instance.collection('singers').snapshots(),
        builder: (
          context,
          snapshot,
        ) {
          *if statement*
          return ListView.builder(
                itemCount: snapshot.data.documents.length,
                itemBuilder: (context, index) => SingleChildScrollView(
                      child: Padding(
                        padding: const EdgeInsets.only(
                            left: 10, right: 10, top: 10, bottom: 0),
                        child: Row(
                              mainAxisAlignment: MainAxisAlignment.center,
                              children: <Widget>[
                                Text(
                                  snapshot.data.documents[index]['songs list'],
                                  style: TextStyle(
                                      fontSize: 20, color: Colors.red[500]),
                                )
                              ]),
                        ),
                      ),
                    )),
          );
        },
      ),
    );
  }
}

Database

Giles Correia Morton · Accepted Answer · 2020-08-07 20:10:29Z

1

Looking at your database and the error message it looks like the array object songs list is the List<dynamic> that is the issue. Instead if you want the Text widget to output the list of songs try

snapshot.data.documents[index]['songs list'].map((e) => e.values.join(,)).join(',')

which will convert the List<dynamic> into a string of values separated by a comma

edited Aug 7, 2020 at 20:10

answered Aug 7, 2020 at 17:53

Giles Correia Morton

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4 Comments

timilehinjegede Over a year ago

It ia a list of Map. The snapshot.data.documents[index]['songs list'] returns a List of Map objects.

Giles Correia Morton Over a year ago

Ah okay, thanks I didn't realise, I've updated my answer to map the list of Maps into strings of their values, then you can join all those into a list of song. If that's your intention.

Mt Khalifa Over a year ago

it works man but it reads all the array in one line and from all the documents. i want it from a single document and every item from an array in a new line since its a ListView.Builder inside a StreamBuilder

Giles Correia Morton Over a year ago

Hey, sorry I missed your reply and sorry about the misunderstanding. From what I can see from your code the list is looping through the documents array itself, so one list item = one document. Therefore the songs are output for every document. If you want the song list for one document could you do a high level list of documents (the list you have at the moment) where the list item is the doc title, the user could then tap into it (or expand or something else) to see a list of songs. This list would be built by making a ListView for snapshot.data.documents[index]['songs list']

Adarsh Balu · Accepted Answer · 2020-08-07 17:52:14Z

0

Try this :

snapshot.data.documents['songs list'][index]['jigar]

answered Aug 7, 2020 at 17:52

Adarsh Balu

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