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This is the database in Firestore: link as you can see it is exactly as it's needed;

However upon running the application from chapter 7 on "The EventDetails model class" we get
Unhandled Exception: Bad state: field does not exist within the DocumentSnapshotPlatform error message.

The error is caused because there's a missing field 'id' in our FireStore database, but we're trying to assign it from the EventDetail.fromMap named constructor

This needs to be updated, as we as a lot of deprecated code lines, such as getDocuments() (in favor of get()), documents() (in favor of docs()) etc;

In the Movie class (page 169), voteAverage is given as type double; this throws an exception:

type 'int' is not a subtype of type 'double' of 'function result'

If I changed this type to var, it passes and I can see that two of the movie averages are 0 (possibly they have no ratings).

it seems you forgot to remove api key)

Chapter 2.
You will find the below codes in the book. Using Map in place of List caused an error in the Dropdown button widget.

final Map<String, int> _measures = {
'Meters': 0,
'Kilogram': 1,
'Grams': 2,
'kilometers': 3,
'Feets': 4,
'Miles': 5,
'Pounds (libs)': 6,
'Ounces': 7

};

I wish the lifespan of the book would be extended by at least keeping the example code up-to-date.
Or stop selling the book.

For one the code in the book does not work.
RenderBox was not laid out: _RenderSingleChildViewport#aa1ea relayoutBoundary=up8 NEEDS-PAINT
At the end of the "completing the ui" step it has you wrap most of the project in a SingleChildScrollView which causes the error.

There is no mention of any of these variables
double sizeX = MediaQuery.of(context).size.width;
double sizeY = MediaQuery.of(context).size.height;
final spacer = Padding(padding: EdgeInsets.only(bottom: sizeY/40));

And Spacer() is used instead of spacer....

How are you going to have the initial commit of the repo be this different from the book? Seems like quite the oversite.

Here is my getList function:

Future<List> getLists() async {
final List<Map<String, dynamic>> maps = await db.query('lists');
// ignore: missing_return
return List.generate(maps.length, (i) {
return ShoppingList(
maps[i]['id'],
maps[i]['name'],
maps[i]['priority'],
);
});
}

I am calling it from here
showData() async {
dynamic bb;
await helper.openDb();
shoppingList = await helper.getLists();

setState(() {
shoppingList=shoppingList;
});
}
}

I am getting the error

type 'List' is not a subtype of type 'int'

It seems that the error originates here:

EventDetail.fromMap( dynamic obj ) {
this.id = obj['id']; // <<<< CRASH
this._description = obj['description'];
this._date = obj['date'];
this._startTime = obj['start_time'];
this._endTime = obj['end_time'];
this._speaker = obj['speaker'];
this._isFavorite = obj['is_favourite'];
}

Not sure why this is happening. Any ideas?

Thanks.

Here is the stack trace:

/flutter: [ERROR:flutter/lib/ui/ui_dart_state.cc(166)] Unhandled Exception: NoSuchMethodError: Class 'QueryDocumentSnapshot' has no instance method '[]'.
Receiver: Instance of 'QueryDocumentSnapshot'
Tried calling:
#0 Object.noSuchMethod (dart:core-patch/object_patch.dart:51:5)
#1 new EventDetail.fromMap (package:events/models/event_detail.dart:14:18)
#2 _EventListState.getDetailsList. (package:events/screens/event_screen.dart:60:54)
#3 MappedListIterable.elementAt (dart:_internal/iterable.dart:417:31)
#4 ListIterator.moveNext (dart:_internal/iterable.dart:343:26)
#5 new List.from (dart:core-patch/array_patch.dart:38:29)
#6 new List.of (dart:core-patch/array_patch.dart:68:17)
#7 ListIterable.toList (dart:_internal/iterable.dart:211:44)
#8 _EventListState.getDetailsList (package:events/screens/event_screen.dart:60:66)

#9 _EventListState.initState (package:events/screens/event_screen.dart:31:7)
#10 StatefulElement._firstBuild (package:flutter/src/widgets/framework.dart:4684:58)
#11 ComponentElement.mount (package:flutter/src/widgets/framework.dart:4520:5)
#12 Element.inflateWidget (package:flutter/src/widgets/framework.dart:3490:14)
#13 Element.updateChild (package:flutter/src/widgets/framework.dart:3258:18)
#14 ComponentElement.performRebuild (package:flutter/src/widgets/framework.dart:4571:16)
#15 Element.rebuild (package:flutter/src/widgets/framework.dart:4262:5)
#16 ComponentElement._firstBuild (package:flutter/src/widgets/framework.dart:4525:5)
#17 ComponentElement.mount (package:flutter/src/widgets/framework.dart:4520:5)
#18 Element.inflateWidget (package:flutter/src/widgets/framework.dart:3490:14)
#19 Element.updateChild (package:flutter/src/widgets/framework.dart:3258:18)
#20 ComponentElement.performRebuild (package:flutter/src/widgets/framework.dart:4571:16)
#21 Element.rebuild (package:flutter/src/widgets/framework.dart:4262:5)
#22 ComponentElement._firstBuild (package:flutter/src/widgets/framework.dart:4525:5)
#23 ComponentElement.mount (package:flutter/src/widgets/framework.dart:4520:5)
#24 Element.inflateWidget (package:flutter/src/widgets/framework.dart:3490:14)
#25 Element.updateChild (package:flutter/src/widgets/framework.dart:3258:18)
#26 ComponentElement.performRebuild (package:flutter/src/widgets/framework.dart:4571:16)
#27 Element.rebuild (package:flutter/src/widgets/framework.dart:4262:5)
#28 ComponentElement._firstBuild (package:flutter/src/widgets/framework.dart:4525:5)
#29 ComponentElement.mount (package:flutter/src/widgets/framework.dart:4520:5)
#30 Element.inflateWidget (package:flutter/src/widgets/framework.dart:3490:14)
#31 MultiChildRenderObjectElement.mount (package:flutter/src/widgets/framework.dart:5991:32)
#32 Element.inflateWidget (package:flutter/src/widgets/framework.dart:3490:14)
#33 Element.updateChild (package:flutter/src/widgets/framework.dart:3258:18)
#34 ComponentElement.performRebuild (package:flutter/src/widgets/framework.dart:4571:16)
#35 StatefulElement.performRebuild (package:flutter/src/widgets/framework.dart:4719:11)
#36 Element.rebuild (package:flutter/src/widgets/framework.dart:4262:5)
#37 ComponentElement._firstBuild (package:flutter/src/widgets/framework.dart:4525:5)
#38 StatefulElement._firstBuild (package:flutter/src/widgets/framework.dart:4710:11)
#39 ComponentElement.mount (package:flutter/src/widgets/framework.dart:4520:5)
#40 Element.inflateWidget (package:flutter/src/widgets/framework.dart:3490:14)
#41 Element.updateChild (package:flutter/src/widgets/framework.dart:3258:18)
#42 ComponentElement.performRebuild (package:flutter/src/widgets/framework.dart:4571:16)
#43 Element.rebuild (package:flutter/src/widgets/framework.dart:4262:5)
#44 ComponentElement._firstBuild (package:flutter/src/widgets/framework.dart:4525:5)
#45 ComponentElement.mount (package:flutter/src/widgets/framework.dart:4520:5)

When I added print(shoppingList.length); this sentence to showData(), such as the following code:

The showData() method in build()：

showData() source code：

Add print(shoppingList.length); to showData()

Future showData() async { 
   await helper.openDb(); 
   shoppingList = await helper.getLists(); 
   // print here
   print(shoppingList.length);
   setState(() { 
     shoppingList = shoppingList; 
   }); 
 }

I found that showData() is actually being called repeatedly all the time.

It seems that showData is called in build, and setState in showData will cause build to be called again, which leads to a circular call.

This should be incorrect, right? Wouldn't this lead to a waste of resources due to non-stop rebuilding?