Beginning app development with Flutterq : create cross-platform mobile apps

Create iOS and Android apps with Flutter using just one codebase. App development on multiple platforms has historically been difficult and complex. This book breaks down complex concepts and tasks into easily digestible segments with examples, pictures, and hands-on labs with starters and solutions. In doing so, you'll develop a basic understanding of the Dart programming language; the entire Flutter development toolchain; the differences between stateful and stateless widgets; and a working knowledge of the architecture of apps. All the most important parts of app development with Flutter are covered in this book. Work with themes and styles. Develop custom widgets. Teach your app to respond to gestures like taps, swipes, and pinches. Design, create and control the layout of your app. Create tools to handle form data entry from users. And ultimately create killer multiscreen apps with navigation, menus, and tabs. Flutter is Google's new framework for creating mobile apps that run on iOS and Android phones both.You had to be a super-developer to write apps for iOS or Android alone. But writing for both? Forget about it! You had to be familiar with Swift, Java/Kotlin, Xcode, Eclipse, and a bunch of other technologies simultaneously. Beginning App Development with Flutter simplifies the entire process. What You'll Learn Get the most out of great Flutter widgets Create custom widgets, both stateless and stateful Exercise expert control over your Flutter layouts Make your app respond to gestures like swiping, pinching and tapping Initiate async Ajax calls to RESTful APIs — including Google Firebase! Who This Book Is For Developers who have coded in Java, C#, C++, or any similar language. It brings app development within the reach of younger developers, so STEM groups are likely to pick up the technology. Managers, product owners, and business analysts need to understand Flutter's capabilities. Praise for Beginning App Development with Flutter 5 Table of Contents 7 About the Author 16 About the Technical Reviewer 17 Who is this book for? 18 Part I: Introduction to Flutter 23 Chapter 1: Hello Flutter 24 What is Flutter? 25 Why Flutter? 26 The other options 26 Native solutions 28 Conclusion 29 Chapter 2: Developing in Flutter 30 The Flutter toolchain 31 The Flutter SDK 31 Installing the flutter SDK 31 IDEs 31 VS Code from Microsoft 32 Android Studio/IntelliJ from JetBrains 32 Which IDE should I use? 32 IDE DevTools 33 Emulators 34 iOS simulator 34 Android emulator 35 Keeping the tools up to date 36 flutter doctor 37 flutter upgrade 38 The Flutter development process 39 Scaffolding the app and files 39 Anatomy of a Flutter project 40 Running your app 42 Running it as a web app 44 Running it on a tethered device 45 Hot reloading 45 Debugging 46 Conclusion 48 Part II: Foundational Flutter 49 Chapter 3: Everything Is Widgets 50 UI as code 52 Built-in Flutter widgets 54 Value widgets 55 Layout widgets 55 Navigation widgets 56 Other widgets 57 How to create your own stateless widgets 57 Widgets have keys 60 Passing a value into your widget 61 Stateless and Stateful widgets 64 So which one should I create? 64 Conclusion 65 Chapter 4: Value Widgets 66 The Text widget 66 The Icon widget 67 The Image widget 68 Embedded images 69 Network images 70 Sizing an image 70 Input widgets 73 Text fields 74 Making your TextField fancy 75 Checkboxes 79 Radio buttons 80 Sliders 81 Dropdowns 82 Putting the form widgets together 84 Form widget 84 FormField widget 86 onSaved 88 validator 88 Validate while typing 88 Validate only after submit attempt 90 One big Form example 90 Conclusion 95 Chapter 5: Responding to Gestures 96 Meet the button family 97 RaisedButton 99 FlatButton and IconButton 100 FloatingActionButton 100 CupertinoButton 101 Dismissible 102 Custom gestures for your custom widgets 102 Step 1: Decide on your gestures and behaviors 103 Step 2: Create your custom widget 104 Step 3: Add a GestureDetector widget 105 Step 4: Associate your gesture with its behavior 106 Example 1: Reacting to a long press 106 Example 2: Pinching to add a new item 108 Example 3: Swiping left or right 109 What if there are two or more gestures happening at the same time? 111 Conclusion 111 Chapter 6: Laying Out Your Widgets 112 Laying out the whole scene 119 MaterialApp widget 119 The Scaffold widget 120 The AppBar widget 121 SafeArea widget 123 SnackBar widget 124 How Flutter decides on a widget’s size 125 The dreaded “unbounded height” error 126 Flutter’s layout algorithm 127 Putting widgets next to or below others 129 Your widgets will never fit! 132 What if there’s extra space left over? 132 mainAxisAlignment 132 crossAxisAlignment 134 Expanded widget 136 What if there’s not enough space? 140 The ListView widget 140 Regular ListView: When you have a few widgets to display 141 ListView.builder: When you’re building widgets from a list of objects 142 Container widget and the box model 143 Alignment and positioning within a Container 145 So how do you determine the size of a Container? 147 Special layout widgets 149 Stack widget 149 GridView widget 150 GridView.extent() 150 GridView.count() 151 The Table widget 153 Conclusion 156 Chapter 7: Navigation and Routing 157 Stack navigation 158 Navigating forward and back 159 Get result after a scene is closed 161 Drawer navigation 162 The Drawer widget 164 Filling the drawer 166 Tab Navigation 168 TabController 169 TabBarView 169 TabBar and Tabs 170 TabBar at the bottom 171 The Dialog widget 171 showDialog() and AlertDialog 172 Responses with a Dialog 173 Navigation methods can be combined 175 Chapter 8: Styling Your Widgets 176 Thinking in Flutter Styles 177 A word about colors 178 Styling Text 180 TextStyle 180 Custom fonts 182 Container decorations 185 Border 187 BorderRadius 189 BoxShape 190 Stacking widgets 193 Positioned widget 195 Card widget 197 Themes 198 Applying theme properties 200 Conclusion 203 Chapter 9: Managing State 204 What is state? 204 What goes in a StatefulWidget? 206 The most important rule about state! 207 Passing state down 208 Lifting state back up 209 An example of state management 210 When should we use state? 215 Advanced state management 217 InheritedWidget 217 BLoC 217 ScopedModel 218 Hooks 218 Provider 219 Redux 219 Whoa! That’s a lot of packages! 220 Conclusion 220 Part III: Above and Beyond 221 Chapter 10: Your Flutter App Can Work with Files 222 Including libraries in your Flutter app 223 Finding a library 223 Adding it to pubspec.yaml 225 Importing the library 225 Using the library 226 Futures, async, and await 226 Why would it wait? 227 How do we get the data from a Future? 228 await 229 async 230 Including a file with your app 231 Writing a file 233 And reading it! 234 Using JSON 235 Writing your app’s memory to JSON 236 Reading JSON into your app’s memory 237 Shared preferences 238 To write preferences 239 To read preferences 239 Conclusion 240 Chapter 11: Making RESTful API Calls with HTTP 241 What is an API call? 242 The flavors of API requests 242 Making an HTTP GET or DELETE request 244 Making an HTTP PUT, POST, or PATCH request 245 HTTP responses to widgets 246 Brute force – The easy way 247 FutureBuilder – The clean way 248 StreamBuilder 250 Strongly typed classes 252 Create a business class 252 Write a .fromJSON() method 253 Use .fromJSON() to hydrate the object 254 One big example 254 Setting up 256 Create the Flutter app 257 Making a strongly typed business class 257 PeopleList.dart 258 A GET request in Flutter 261 A DELETE request in Flutter 261 PeopleUpsert.dart 262 A POST and PUT request in Flutter 266 Conclusion 268 Chapter 12: Using Firebase with Flutter 269 Introducing Firebase 270 Cloud Firestore 271 Cloud Functions 272 Authentication 273 Setting up Firebase itself 273 (1) Creating a Firebase project 274 (2) Creating the database 277 (3) Creating an iOS app 281 (4) Creating an Android app 287 Install the google-services.json file 289 Adding to the gradle files 290 (5) Adding FlutterFire plugins 291 Using Firestore 292 To get a collection 293 To query 295 To upsert 295 To delete 296 Where to go from here 297 Appendix A: Dart Language Overview 300 What is Dart? 300 Expected features – Dart Cheatsheet 301 Data types 301 Arrays/lists 302 Conditional expressions 302 Looping 303 Classes 303 Class constructors 304 Unexpected things about Dart 304 Type inference 305 final and const 305 Variables are initialized to null 306 String interpolation with $ 307 Multiline strings 307 Spread operator 307 Map 308 Functions are objects 308 Big arrow/Fat arrow 309 Named function parameters 309 Omitting “new” and “this.” 310 Class constructor parameter shorthand 311 Private class members 312 Mixins 312 The cascade operator (..) 313 No overloading 314 Named constructors 314 Index 316 "Create iOS and Android apps with Flutter using just one codebase. App development on multiple platforms has historically been difficult and complex. This book breaks down complex concepts and tasks into easily digestible segments with examples, pictures, and hands-on labs with starters and solutions. In doing so, you'll develop a basic understanding of the Dart programming language; the entire Flutter development toolchain; the differences between stateful and stateless widgets; and a working knowledge of the architecture of apps. All the most important parts of app development with Flutter are covered in this book. Work with themes and styles. Develop custom widgets. Teach your app to respond to gestures like taps, swipes, and pinches. Design, create and control the layout of your app. Create tools to handle form data entry from users. And ultimately create killer multiscreen apps with navigation, menus, and tabs. Flutter is Google's new framework for creating mobile apps that run on iOS and Android phones both. You had to be a super-developer to write apps for iOS or Android alone. But writing for both? Forget about it! You had to be familiar with Swift, Java/Kotlin, Xcode, Eclipse, and a bunch of other technologies simultaneously. Beginning App Development with Flutter simplifies the entire process. What You'll Learn: Get the most out of great Flutter widgets ; Create custom widgets, both stateless and stateful ; Exercise expert control over your Flutter layouts ; Make your app respond to gestures like swiping, pinching and tapping ; Initiate async Ajax calls to RESTful APIs--including Google Firebase! Who This Book Is For: Developers who have coded in Java, C#, C++, or any similar language. It brings app development within the reach of younger developers, so STEM groups are likely to pick up the technology. Managers, product owners, and business analysts need to understand Flutter's capabilities."--Amazon.com Front Matter ....Pages i-xxv Front Matter ....Pages 1-1 Hello Flutter (Rap Payne)....Pages 3-8 Developing in Flutter (Rap Payne)....Pages 9-27 Front Matter ....Pages 29-29 Everything Is Widgets (Rap Payne)....Pages 31-46 Value Widgets (Rap Payne)....Pages 47-76 Responding to Gestures (Rap Payne)....Pages 77-92 Laying Out Your Widgets (Rap Payne)....Pages 93-137 Navigation and Routing (Rap Payne)....Pages 139-157 Styling Your Widgets (Rap Payne)....Pages 159-186 Managing State (Rap Payne)....Pages 187-203 Front Matter ....Pages 205-205 Your Flutter App Can Work with Files (Rap Payne)....Pages 207-225 Making RESTful API Calls with HTTP (Rap Payne)....Pages 227-254 Using Firebase with Flutter (Rap Payne)....Pages 255-285 Back Matter ....Pages 287-309