title: Flutter - remove a firebase document onTap()
body: <p>I have a ListView, filled with Firebase collection as chat messages.</p>
  
  <p>When the user long press a ListTile (an item on the list), I show a BottomSheet.</p>
  
  <p>When the user clicks the <code>Delete</code> button on the BottomSheet, the document should be removed. I'm unable to find a way to remove the selected document after tapping the "Delete" button.</p>
  
  <p>The listview widget:</p>
  
  <pre><code>return ListView.builder(
      padding: new EdgeInsets.all(8.0),
      reverse: true,
      itemCount: snapshot.data.documents.length,
      itemBuilder: (_, int index) {
      var message = snapshot.data.documents[index]["content"];
      var from = snapshot.data.documents[index]["idFrom"];
      return new ListTile(
          leading: new CircleAvatar(
              backgroundColor: Colors.blue,
              child: new Image.network(
                  "http://res.cloudinary.com/kennyy/image/upload/v1531317427/avatar_z1rc6f.png")),
          title: new Row(
          children: &lt;Widget&gt;[
              new Expanded(child: new Text(message))
          ]
          ),
          subtitle: new Text(from),
          onLongPress: () {
          showModalBottomSheet&lt;void&gt;(context: context,
              builder: (BuildContext context) {
                  return Container(
                      child: new Wrap(
                      children: &lt;Widget&gt;[
                          new ListTile(
                          leading: new Icon(Icons.delete),
                          title: new Text('Delete'),
                          onTap: () =&gt;
                                            // Remove the tapped document here - how?
                                            print(snapshot.data.documents[index]["id"])
                                            Firestore.instance.collection("chats").document("ROOM_1")
                                            .collection("messages").document(snapshot.data.documents[index]["id"])
                                            .delete();
                                        )
                          )
                      ]
                      )
                  );
              });
          }
      );
  });
  </code></pre>
  
  <p>I need to find a way to remove the document in the <code>onTap()</code> method. not sure why, but even when I do:</p>
  
  <pre><code> onTap: () =&gt; {
       // Remove the tapped document here - how?
       const id = snapshot.data.documents[index]["id"];
   },
  </code></pre>
  
  <p>the IDE retruns an error <code>Expected an identifier</code></p>