book: init flutter snippets

.github/workflows/book.yml

@@ -44,6 +44,9 @@ jobs:
         distribution: "temurin"
         java-version: 17
 
+    # Required for dart/flutter snippets
+    - uses: subosito/flutter-action@v2
+
     - name: Check
       run: just check-book
 

book/snippets/flutter/.gitignore

@@ -0,0 +1,7 @@
+# https://dart.dev/guides/libraries/private-files
+# Created by `dart pub`
+.dart_tool/
+packages/
+.flutter-version
+.flutter-plugins
+.flutter-plugins-dependencies

book/snippets/flutter/analysis_options.yaml

@@ -0,0 +1,30 @@
+# This file configures the static analysis results for your project (errors,
+# warnings, and lints).
+#
+# This enables the 'recommended' set of lints from `package:lints`.
+# This set helps identify many issues that may lead to problems when running
+# or consuming Dart code, and enforces writing Dart using a single, idiomatic
+# style and format.
+#
+# If you want a smaller set of lints you can change this to specify
+# 'package:lints/core.yaml'. These are just the most critical lints
+# (the recommended set includes the core lints).
+# The core lints are also what is used by pub.dev for scoring packages.
+
+include: package:lints/recommended.yaml
+
+# Uncomment the following section to specify additional rules.
+
+# linter:
+#   rules:
+#     - camel_case_types
+
+analyzer:
+  exclude:
+    - packages/**
+
+# For more information about the core and recommended set of lints, see
+# https://dart.dev/go/core-lints
+
+# For additional information about configuring this file, see
+# https://dart.dev/guides/language/analysis-options

book/snippets/flutter/justfile

@@ -0,0 +1,5 @@
+#!/usr/bin/env just --justfile
+
+test:
+    flutter pub get
+    dart analyze --fatal-infos

book/snippets/flutter/lib/hello.dart

@@ -0,0 +1,25 @@
+// ANCHOR: full
+
+import 'package:nostr_sdk/nostr_sdk.dart';
+
+Future<void> hello() async {
+  // ANCHOR: client
+  Keys keys = Keys.generate();
+  NostrSigner signer = NostrSigner.keys(keys: keys);
+  Client client = Client.builder().signer(signer: signer).build();
+  // ANCHOR_END: client
+
+  // ANCHOR: connect
+  await client.addRelay(url: "wss://relay.damus.io");
+  await client.connect();
+  // ANCHOR_END: connect
+
+  // ANCHOR: publish
+  // TODO
+  // ANCHOR_END: publish
+
+  // ANCHOR: output
+  // TODO
+  // ANCHOR_END: output
+}
+// ANCHOR_END: full