docs: minimise the copy/think/paste needed to get the minimal impleme… (#2951)

* docs: minimise the copy/think/paste needed to get the minimal implementation working

* fix: revert tag name & add closing

---------

Co-authored-by: Ewan Nisbet <ewan-git@thatdogmachine.com>

docs/lib/snippets/setup/database.dart

@@ -1,21 +1,19 @@
+// #docregion after_generation
 // #docregion before_generation
 import 'package:drift/drift.dart';
 
 // #enddocregion before_generation
+// #enddocregion after_generation
 
-// #docregion open
-// These imports are necessary to open the sqlite3 database
+// #docregion after_generation
+// These additional imports are necessary to open the sqlite3 database
 import 'dart:io';
-
 import 'package:drift/native.dart';
 import 'package:path_provider/path_provider.dart';
 import 'package:path/path.dart' as p;
 import 'package:sqlite3/sqlite3.dart';
 import 'package:sqlite3_flutter_libs/sqlite3_flutter_libs.dart';
 
-// ... the TodoItems table definition stays the same
-// #enddocregion open
-
 // #docregion before_generation
 part 'database.g.dart';
 
@@ -27,25 +25,22 @@ class TodoItems extends Table {
   IntColumn get category => integer().nullable()();
 }
 // #enddocregion table
-// #docregion open
 
 @DriftDatabase(tables: [TodoItems])
 class AppDatabase extends _$AppDatabase {
-// #enddocregion open
+// #enddocregion before_generation
+// #enddocregion after_generation
   // After generating code, this class needs to define a `schemaVersion` getter
   // and a constructor telling drift where the database should be stored.
   // These are described in the getting started guide: https://drift.simonbinder.eu/getting-started/#open
-// #enddocregion before_generation
-// #docregion open
+// #docregion after_generation
   AppDatabase() : super(_openConnection());
 
   @override
   int get schemaVersion => 1;
 // #docregion before_generation
 }
-// #enddocregion before_generation, open
-
-// #docregion open
+// #enddocregion before_generation
 
 LazyDatabase _openConnection() {
   // the LazyDatabase util lets us find the right location for the file async.
@@ -70,7 +65,7 @@ LazyDatabase _openConnection() {
     return NativeDatabase.createInBackground(file);
   });
 }
-// #enddocregion open
+// #enddocregion after_generation
 
 class WidgetsFlutterBinding {
   static void ensureInitialized() {}

docs/pages/docs/setup.md

@@ -81,7 +81,7 @@ to store todo items for a todo list app.
 Everything there is to know about defining tables in Dart is described on the [Dart tables]({{'Dart API/tables.md' | pageUrl}}) page.
 If you prefer using SQL to define your tables, drift supports that too! You can read all about the [SQL API]({{ 'SQL API/index.md' | pageUrl }}) here.
 
-For now, the contents of `database.dart` are:
+For now, populate the contents of `database.dart` with:
 
 {% include "blocks/snippet" snippets = snippets name = 'before_generation' %}
 
@@ -97,10 +97,11 @@ After running either command, the `database.g.dart` file containing the generate
 class will have been generated.
 You will now see errors related to missing overrides and a missing constructor. The constructor
 is responsible for telling drift how to open the database. The `schemaVersion` getter is relevant
-for migrations after changing the database, we can leave it at `1` for now. The database class
-now looks like this:
-<a name="open">
-{% include "blocks/snippet" snippets = snippets name = 'open' %}
+for migrations after changing the database, we can leave it at `1` for now. Update `database.dart`
+so it now looks like this:
+
+<a name="open"></a>
+{% include "blocks/snippet" snippets = snippets name = 'after_generation' %}
 
 The Android-specific workarounds are necessary because sqlite3 attempts to use `/tmp` to store
 private data on unix-like systems, which is forbidden on Android. We also use this opportunity