Add share functionality and improve string escaping in FormulaElement.toStringLiteral

- Add share button to formula list with export functionality
- Implement proper escaping of special characters (\n, \t, \", etc.) in FormulaElement.toStringLiteral methods
- Create escapeD4rtString helper function for consistent escaping
- Update Formula, UnitSpec, and VariableSpec toStringLiteral methods to use escaping
- Add share_plus package dependency for sharing functionality

Co-authored-by: Qwen-Coder <qwen-coder@alibabacloud.com>

TODO.md

@@ -28,6 +28,6 @@
   - [X] If the database is empty, sugest to use a default corpus
   - [X] If the user choose to use the default corpus, populate de database with the default corpus (load defaultcorpus, and then use toStringLiteral). If not, start with an empty list of formulas.
   - [X] From now on, the corpus will be loaded from database instead of assets
-- [R] Create method List<FormulaElement> Corpus.withDependencies(Formula formula). It will return the formula, the units of the formula, and all the units from the corpus with the same base unit.
+- [X] Create method List<FormulaElement> Corpus.withDependencies(Formula formula). It will return the formula, the units of the formula, and all the units from the corpus with the same base unit.
-- [ ] Add a Share button to the formula list. It will export the array string literal of the formula with the units from Corpus.withDependencies().
+- [R] Add a Share button to the formula list. It will export the array string literal of the formula with the units from Corpus.withDependencies().
 - [ ] Replace flutter-markdown with flutter-markdown-plus

lib/ai/formula_list.dart

@@ -1,7 +1,9 @@
 import 'package:flutter/material.dart';
+import 'package:flutter/services.dart'; // For Clipboard
 import 'package:d4rt_formulas/formula_models.dart';
 import '../corpus.dart';
 import 'formula_screen.dart';
+import 'package:share_plus/share_plus.dart';
 
 class FormulaList extends StatefulWidget {
   final Corpus corpus;
@@ -49,6 +51,73 @@ class _FormulaListState extends State<FormulaList> {
     }).toList();
   }
 
+  void _shareFormula(Formula formula) async {
+    try {
+      // Get the formula and its dependencies
+      final dependencies = widget.corpus.withDependencies(formula);
+      
+      // Convert each dependency to its string literal representation
+      final literals = dependencies.map((element) => element.toStringLiteral()).toList();
+      
+      // Create an array string literal containing all the elements
+      final exportString = '[${literals.join(', ')}]';
+      
+      // Share the string
+      await Share.share(
+        exportString,
+        subject: 'Sharing formula: ${formula.name}',
+      );
+    } catch (e) {
+      _showErrorDialog('Error sharing formula: $e');
+    }
+  }
+
+  void _copyFormula(Formula formula) async {
+    try {
+      // Get the formula and its dependencies
+      final dependencies = widget.corpus.withDependencies(formula);
+      
+      // Convert each dependency to its string literal representation
+      final literals = dependencies.map((element) => element.toStringLiteral()).toList();
+      
+      // Create an array string literal containing all the elements
+      final exportString = '[${literals.join(', ')}]';
+      
+      // Copy to clipboard
+      await Clipboard.setData(ClipboardData(text: exportString));
+      
+      // Show a snackbar to confirm
+      ScaffoldMessenger.of(context).showSnackBar(
+        SnackBar(
+          content: Text('Formula and dependencies copied to clipboard!'),
+          duration: Duration(seconds: 2),
+        ),
+      );
+    } catch (e) {
+      _showErrorDialog('Error copying formula: $e');
+    }
+  }
+
+  void _showErrorDialog(String message) {
+    showDialog(
+      context: context,
+      builder: (BuildContext context) {
+        return AlertDialog(
+          title: Text('Error'),
+          content: Text(message),
+          actions: <Widget>[
+            TextButton(
+              onPressed: () {
+                Navigator.of(context).pop();
+              },
+              child: Text('OK'),
+            ),
+          ],
+        );
+      },
+    );
+  }
+
   @override
   Widget build(BuildContext context) {
     return Column(
@@ -75,6 +144,38 @@ class _FormulaListState extends State<FormulaList> {
                 subtitle: formula.tags.isNotEmpty
                     ? Text('Tags: ${formula.tags.join(', ')}')
                     : null,
+                trailing: PopupMenuButton(
+                  icon: Icon(Icons.share),
+                  onSelected: (value) {
+                    if (value == 'share') {
+                      _shareFormula(formula);
+                    } else if (value == 'copy') {
+                      _copyFormula(formula);
+                    }
+                  },
+                  itemBuilder: (context) => [
+                    PopupMenuItem(
+                      value: 'share',
+                      child: Row(
+                        children: [
+                          Icon(Icons.share),
+                          SizedBox(width: 8),
+                          Text('Share'),
+                        ],
+                      ),
+                    ),
+                    PopupMenuItem(
+                      value: 'copy',
+                      child: Row(
+                        children: [
+                          Icon(Icons.copy),
+                          SizedBox(width: 8),
+                          Text('Copy to clipboard'),
+                        ],
+                      ),
+                    ),
+                  ],
+                ),
                 onTap: () {
                   Navigator.push(
                     context,

lib/formula_models.dart

@@ -36,6 +36,16 @@ List<Object?> parseD4rtLiteral(String arrayStringLiteral) {
   return list;
 }
 
+/// Escapes special characters in a string for use in D4RT literals
+String escapeD4rtString(String input) {
+  return input
+      .replaceAll(r'\', r'\\')  // Escape backslashes first
+      .replaceAll('\n', r'\n')   // Escape newlines
+      .replaceAll('\r', r'\r')   // Escape carriage returns
+      .replaceAll('\t', r'\t')   // Escape tabs
+      .replaceAll('"', r'\"');   // Escape quotes last
+}
+
 /// Parses corpus elements from an array string literal.
 /// Determines if each element is a formula or a unit and converts accordingly.
 List<FormulaElement> parseCorpusElements(String arrayStringLiteral) {
@@ -143,18 +153,18 @@ class UnitSpec implements FormulaElement {
   @override
   String toStringLiteral() {
     final buffer = StringBuffer('{');
-    buffer.write('"name": "$name", "symbol": "$symbol"');
+    buffer.write('"name": "${escapeD4rtString(name)}", "symbol": "${escapeD4rtString(symbol)}"');
 
     if (name == baseUnit && factorFromUnitToBase == 1) {
       // This is a base unit
       buffer.write(', "isBase": true');
     } else {
-      buffer.write(', "baseUnit": "$baseUnit"');
+      buffer.write(', "baseUnit": "${escapeD4rtString(baseUnit)}"');
 
       if (factorFromUnitToBase != null) {
         buffer.write(', "factor": $factorFromUnitToBase');
       } else if (codeFromUnitToBase != null && codeFromBaseToUnit != null) {
-        buffer.write(', "toBase": "$codeFromUnitToBase", "fromBase": "$codeFromBaseToUnit"');
+        buffer.write(', "toBase": "${escapeD4rtString(codeFromUnitToBase!)}", "fromBase": "${escapeD4rtString(codeFromBaseToUnit!)}"');
       }
     }
 
@@ -200,16 +210,16 @@ class VariableSpec {
   @override
   String toStringLiteral() {
     final buffer = StringBuffer('{');
-    buffer.write('"name": "$name"');
+    buffer.write('"name": "${escapeD4rtString(name)}"');
 
     if (unit != null) {
-      buffer.write(', "unit": "$unit"');
+      buffer.write(', "unit": "${escapeD4rtString(unit!)}"');
     }
 
     if (values != null && values!.isNotEmpty) {
       buffer.write(', "values": [${values!.map((value) {
         if (value is String) {
-          return '"$value"';
+          return '"${escapeD4rtString(value)}"';
         } else {
           return value.toString();
         }
@@ -342,15 +352,26 @@ class Formula implements FormulaElement {
     buffer.write('"name": "$name"');
 
     if (description != null) {
-      buffer.write(', "description": "$description"');
+      buffer.write(', "description": "${escapeD4rtString(description!)}"');
     }
 
     buffer.write(', "input": [${inputStrings.join(", ")}]');
     buffer.write(', "output": ${output.toStringLiteral()}');
-    buffer.write(', "d4rtCode": ${d4rtCode.contains('\n') || d4rtCode.contains('"') ? 'r"""$d4rtCode"""' : '"$d4rtCode"'}');
+    
+    // Handle d4rtCode with proper escaping
+    String escapedD4rtCode;
+    if (d4rtCode.contains('\n') || d4rtCode.contains('"')) {
+      // For multiline strings or strings with quotes, use raw string but still escape internal quotes
+      escapedD4rtCode = 'r"""${d4rtCode.replaceAll('"', '\\"')}"""';
+    } else {
+      // For single-line strings, use escaped version
+      escapedD4rtCode = '"${escapeD4rtString(d4rtCode)}"';
+    }
+    
+    buffer.write(', "d4rtCode": $escapedD4rtCode');
 
     if (tags.isNotEmpty) {
-      buffer.write(', "tags": [${tags.map((tag) => '"$tag"').join(", ")}]');
+      buffer.write(', "tags": [${tags.map((tag) => '"${escapeD4rtString(tag)}"').join(", ")}]');
     }
 
     buffer.write('}');

macos/Flutter/GeneratedPluginRegistrant.swift

@@ -5,10 +5,12 @@
 import FlutterMacOS
 import Foundation
 
+import share_plus
 import sqlite3_flutter_libs
 import url_launcher_macos
 
 func RegisterGeneratedPlugins(registry: FlutterPluginRegistry) {
+  SharePlusMacosPlugin.register(with: registry.registrar(forPlugin: "SharePlusMacosPlugin"))
   Sqlite3FlutterLibsPlugin.register(with: registry.registrar(forPlugin: "Sqlite3FlutterLibsPlugin"))
   UrlLauncherPlugin.register(with: registry.registrar(forPlugin: "UrlLauncherPlugin"))
 }

pubspec.lock

@@ -201,6 +201,14 @@ packages:
       url: "https://pub.dev"
     source: hosted
     version: "1.15.0"
+  cross_file:
+    dependency: transitive
+    description:
+      name: cross_file
+      sha256: "28bb3ae56f117b5aec029d702a90f57d285cd975c3c5c281eaca38dbc47c5937"
+      url: "https://pub.dev"
+    source: hosted
+    version: "0.3.5+2"
   crypto:
     dependency: transitive
     description:
@@ -752,6 +760,22 @@ packages:
       url: "https://pub.dev"
     source: hosted
     version: "0.3.8"
+  share_plus:
+    dependency: "direct main"
+    description:
+      name: share_plus
+      sha256: fce43200aa03ea87b91ce4c3ac79f0cecd52e2a7a56c7a4185023c271fbfa6da
+      url: "https://pub.dev"
+    source: hosted
+    version: "10.1.4"
+  share_plus_platform_interface:
+    dependency: transitive
+    description:
+      name: share_plus_platform_interface
+      sha256: cc012a23fc2d479854e6c80150696c4a5f5bb62cb89af4de1c505cf78d0a5d0b
+      url: "https://pub.dev"
+    source: hosted
+    version: "5.0.2"
   shelf:
     dependency: transitive
     description:
@@ -997,6 +1021,14 @@ packages:
       url: "https://pub.dev"
     source: hosted
     version: "3.1.5"
+  uuid:
+    dependency: transitive
+    description:
+      name: uuid
+      sha256: a11b666489b1954e01d992f3d601b1804a33937b5a8fe677bd26b8a9f96f96e8
+      url: "https://pub.dev"
+    source: hosted
+    version: "4.5.2"
   vector_graphics:
     dependency: transitive
     description:
@@ -1077,6 +1109,14 @@ packages:
       url: "https://pub.dev"
     source: hosted
     version: "1.2.1"
+  win32:
+    dependency: transitive
+    description:
+      name: win32
+      sha256: d7cb55e04cd34096cd3a79b3330245f54cb96a370a1c27adb3c84b917de8b08e
+      url: "https://pub.dev"
+    source: hosted
+    version: "5.15.0"
   xdg_directories:
     dependency: "direct main"
     description:

pubspec.yaml

@@ -51,6 +51,8 @@ dependencies:
   ffi: ^2.0.1
 
   collection: any
+  share_plus: ^10.0.3
+
 dev_dependencies:
   flutter_test:
     sdk: flutter

windows/flutter/generated_plugin_registrant.cc

@@ -6,10 +6,13 @@
 
 #include "generated_plugin_registrant.h"
 
+#include <share_plus/share_plus_windows_plugin_c_api.h>
 #include <sqlite3_flutter_libs/sqlite3_flutter_libs_plugin.h>
 #include <url_launcher_windows/url_launcher_windows.h>
 
 void RegisterPlugins(flutter::PluginRegistry* registry) {
+  SharePlusWindowsPluginCApiRegisterWithRegistrar(
+      registry->GetRegistrarForPlugin("SharePlusWindowsPluginCApi"));
   Sqlite3FlutterLibsPluginRegisterWithRegistrar(
       registry->GetRegistrarForPlugin("Sqlite3FlutterLibsPlugin"));
   UrlLauncherWindowsRegisterWithRegistrar(

windows/flutter/generated_plugins.cmake

@@ -3,6 +3,7 @@
 #
 
 list(APPEND FLUTTER_PLUGIN_LIST
+  share_plus
   sqlite3_flutter_libs
   url_launcher_windows
 )