- It is the file that directs requests to specific places based on their address passed.
- Instance Variables & :locals hash
## Models, Databases, Relationships in Rails | |
#### What is the difference between a primary key and a foreign key? Where would we find a primary key? What would it be called by default? Where would we find a foreign key? What is the naming convention for a foreign key? | |
* Primary key is a unique identifier in Table. It can exist as a foreign key in AnotherTable or other tables with which it has a relationship. "id" - default name. "table_id" in AnotherTable. | |
#### Write down one example of: | |
* Instructor has one office, computer has one charger | |
#### Write down two examples of a one-to-many relationship. | |
* Computer has many usb ports, company has many full time employees |
Group Member Names: Deb, Kris, Mark
import 'package:flutter/cupertino.dart'; | |
class UndoChangeNotifier<T> extends ChangeNotifier { | |
final List<T> _history; | |
int _historyIndex = -1; | |
UndoChangeNotifier(T initialState) : _history = [initialState]; | |
T get state => hasState ? _history[_historyIndex] : null; |